Once again, new research on items I have already written about is being reported at an overwhelming pace. This latest update includes alarming news about folic acid, (yes, I know I just wrote about it!) and current reports on aspirin, broccoli, diet, fish, green tea, vitamins, especially D, and alcohol and wine.
My reactions to new research – I will stay away from multi-vitamins, continue to drink red wine in moderation, keep drinking green tea.
Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer
A study led by researchers at the University of Southern California (USC) found that men who took a daily folic acid supplement of 1 mg daily had more than twice the risk of prostate cancer compared with men who took a placebo.
The finding came from a secondary analysis of the Aspirin/Folate Polyp Prevention Study (AFPP), a placebo-controlled randomized trial to determine the impact of aspirin and folic acid on colon polyps in men and women who were at high risk for the disease. The results appear in the March 10 online issue of the Journal of the National Cancer Institute.
Folic acid (folate) is a B vitamin found in many vegetables, beans, fruits and whole grains. While evidence of its ability to reduce neural tube defects in infants while taken by the mother before or during pregnancy has been well documented, its effects on other conditions are unclear.
“We know that adequate folate levels are important in the prevention of several cancer types, cardiovascular and neurological diseases,” says lead author Jane Figueiredo, Ph.D., assistant professor of preventive medicine at the Keck School of Medicine of USC. “However, little has been known about its role in prostate cancer. Our objective was to investigate the relationship between folic acid supplements and dietary folate and risk of prostate cancer.”
The AFPP study was conducted between 1994 and 2006 and found that aspirin reduced the risk of colon polyps while folic acid had a negative effect and increased the risk of advanced and multiple polyps. The first analysis did not address the impact of folic acid supplements on prostate cancer risk. Previous observational studies have been inconsistent. Some studies suggest that increased folate in the diet or in supplements might actually lower the risk of prostate cancer, and others have suggested no effect or even a potential harmful effect.
In the secondary analysis, researchers looked at prostate cancer incidence among 643 men who were randomly assigned to 1 mg daily folic acid supplements or placebo in the AFPP study and who enrolled in an extended follow-up study. The estimated prostate cancer risk was 9.7 percent at 10 years in men assigned to folate, compared with 3.3 percent in men assigned to placebo.
By contrast, dietary folate intake and plasma folate showed a trend toward reduced risk of prostate cancer, although the difference did not reach statistical significance. It remains unclear why dietary and circulating folate among non-multivitamin users may be inversely associated with risk, Figueiredo says.
“The synthetic form of folate, folic acid, found in supplements, is more bioavailable compared to folate from dietary sources and we know the amount of folate available is critical,” she says. “Adequate levels of folate may be beneficial, but too much folate is unlikely to be beneficial.”
Alternatively, these results may be due to chance, and replication by other studies is needed, she notes.
“These findings highlight the potentially complex role of folate in prostate cancer. The possibility of different effects from folic acid-containing supplements versus natural sources of folate definitely merits further investigation.”
Aspirin Improves Survival in Women with Stable Heart Disease, According to WHI Study
Less Than One-Half Report Regular Aspirin Use
New results from the Women’s Health Initiative (WHI) Observational Study provide additional evidence that aspirin may reduce the risk of death in postmenopausal women who have heart disease or who have had a stroke. Jacques Rossouw, M.D., chief of the Women’s Health Initiative Branch at the National Heart, Lung, and Blood Institute (NHLBI), is available to comment on these findings. NHLBI, part of the National Institutes of Health, funded the research.
The study also provides new insight into aspirin dosing for women, suggesting that a lower dose of aspirin (81 milligrams, or mg) is as effective as a higher dose (325 mg). This is good news for women who might be concerned with internal bleeding, a well-known risk of aspirin that may be more likely with higher doses of aspirin, according to other studies. However, randomized clinical trials are needed to determine the optimal doses of aspirin in women with cardiovascular disease.
“Aspirin Use, Dose, and Clinical Outcomes in Postmenopausal Women with Stable Cardiovascular Disease – The Women’s Health Initiative Observational Study,” appears in the March issue of the journal Circulation: Cardiovascular Quality and Outcomes and was published online March 5, 2009.
Scientific evidence indicates that, in general, aspirin lowers the risk of death and incidence of heart attack and stroke in patients with a history of cardiovascular disease; however, the benefits of aspirin in women with stable cardiovascular disease in particular are unknown. In this study, researchers analyzed data from 8,928 postmenopausal women who had previously had a heart attack, stroke or transient ischemic attack (TIA, or mini-stroke), angina, or angioplasty or coronary bypass surgery to improve blood flow. Participants were followed for an average of 6.5 years.
Compared to those who did not report taking aspirin, regular aspirin users had a 25 percent lower risk of death from cardiovascular disease and a 14 percent lower risk of death from any cause. Overall, aspirin use did not significantly decrease the risk of heart attack, stroke, or other cardiovascular events, except among women in their seventies. There were no significant differences in death rates or other outcomes between women taking 81 mg of aspirin compared to those taking 325 mg.
The size of the WHI Observational Study and the diversity of participants provide valuable insight into the use of medications in the primary care setting. For example, the study found that only 46 percent of women with stable cardiovascular disease in the study reported taking aspirin regularly, despite current guidelines recommendations. In addition, subgroup analyses indicate that black women and women with Medicaid insurance were less likely to use aspirin as recommended, compared to women of other ethnic groups and insurance status.
The WHI is a major, 15-year research program designed to address the most frequent causes of death, disability, and poor quality of life in postmenopausal women: cardiovascular disease, cancer, and osteoporosis. The WHI Observational Study is a nationwide, prospective study to examine the association between clinical, socioeconomic, behavioral, and dietary risk factors and the subsequent incidence of several health outcomes. The Observational Study followed 93,676 postmenopausal women between the ages of 50 and 79 for an average of 8 years. Participants filled out health forms and visited their clinic physician periodically; participants were not required to take any medication or change their health habits.
Broccoli may help protect against respiratory conditions like asthma
Here's another reason to eat your broccoli: UCLA researchers report that a naturally occurring compound found in broccoli and other cruciferous vegetables may help protect against respiratory inflammation that causes conditions like asthma, allergic rhinitis and chronic obstructive pulmonary disease.
Published in the March edition of the journal Clinical Immunology, the research shows that sulforaphane, a chemical in broccoli, triggers an increase of antioxidant enzymes in the human airway that offers protection against the onslaught of free radicals that we breathe in every day in polluted air, pollen, diesel exhaust and tobacco smoke. A supercharged form of oxygen, free radicals can cause oxidative tissue damage, which leads to inflammation and respiratory conditions like asthma.
"This is one of the first studies showing that broccoli sprouts — a readily available food source — offered potent biologic effects in stimulating an antioxidant response in humans," said Dr. Marc Riedl, the study's principal investigator and an assistant professor of clinical immunology and allergy at the David Geffen School of Medicine at UCLA.
"We found a two- to three-fold increase in antioxidant enzymes in the nasal airway cells of study participants who had eaten a preparation of broccoli sprouts," Riedl said. "This strategy may offer protection against inflammatory processes and could lead to potential treatments for a variety of respiratory conditions."
The UCLA team worked with 65 volunteers who were given varying oral doses of either broccoli or alfalfa sprout preparations for three days. Broccoli sprouts are the richest natural source of sulforaphane; the alfalfa sprouts, which do not contain the compound, served as a placebo.
Rinses of nasal passages were collected at the beginning and end of the study to assess the gene expression of antioxidant enzymes in cells of the upper airways. Researchers found significant increases of antioxidant enzymes at broccoli sprout doses of 100 grams and higher, compared with the placebo group.
The maximum broccoli sprout dosage of 200 grams generated a 101-percent increase of an antioxidant enzyme called GSTP1 and a 199-percent increase of another key enzyme called NQO1.
"A major advantage of sulforaphane is that it appears to increase a broad array of antioxidant enzymes, which may help the compound's effectiveness in blocking the harmful effects of air pollution," Riedl said.
According to the authors, no serious side effects occurred in study participants receiving broccoli sprouts, demonstrating that this may be an effective, safe antioxidant strategy to help reduce the inflammatory impact of free radicals.
Riedl notes that more research needs to be done to examine the benefits of sulforaphane for specific respiratory conditions. It is too early to recommend a particular dosage.
Riedl recommends including broccoli and other cruciferous vegetables as part of a healthy diet.
Vegetable-based drug could inhibit melanoma
Compounds extracted from green vegetables such as broccoli and cabbage could be a potent drug against melanoma, according to cancer researchers. Tests on mice suggest that these compounds, when combined with selenium, target tumors more safely and effectively than conventional therapy.
"There are currently no drugs to target the proteins that trigger melanoma," said Gavin Robertson, associate professor of pharmacology, pathology and dermatology, Penn State College of Medicine. "We have developed drugs from naturally occurring compounds that can inhibit the growth of tumors in mice by 50 to 60 percent with a very low dose."
Robertson and his colleagues previously showed the therapeutic potential of targeting the Akt3 protein in inhibiting the development of melanoma. The search for a drug to block the protein led them to a class of compounds called isothiocyanates.
These naturally occurring chemicals found in cruciferous vegetables are known to have certain cancer-fighting properties. However, the potency of these compounds is so low that a successful drug would require large impractical amounts of these compounds.
Instead, the Penn State researchers rewired the compounds by replacing their sulfur bonds with selenium. The result, they believe, is a more potent drug that can be delivered intravenously in low doses.
"Selenium deficiency is common in cancer patients, including those diagnosed with metastatic melanoma," explained Robertson, whose findings appear in the March edition of Clinical Cancer Research. "Besides, selenium is known to destabilize Akt proteins in prostate cancer cells."
To study the effectiveness of the new drug -- isoselenocyanate -- researchers injected mice with 10 million cancer cells. Six days later, when the animals developed large tumors, they were divided into two groups and treated separately with either the vegetable compounds or the compounds supplemented with selenium.
"We found that the selenium-enhanced compounds significantly reduced the production of Akt3 protein and shut down its signaling network," explained Robertson, who is also associate director of translational research and leader of the experimental therapeutics program at Penn State Hershey Cancer Institute. The modified compounds also reduced the growth of tumors by 60 percent, compared to the vegetable-based compounds alone.
When the researchers exposed three different human melanoma cell lines to the two compounds, the selenium-enhanced drug worked better on some cell lines than others. The efficiency was from 30 to 70 percent depending on the cell line.
The exact mechanism of how selenium inhibits cancer remains unclear. However Robertson, who has a filed provisional patent on the discovery, is convinced that the use of naturally occurring compounds that target cancer-causing proteins could lead to more effective ways of treating melanoma.
"We have harnessed something found in nature to target melanoma," said Robertson. "And since we only need tiny amounts to kill the cancer cells, it means even less toxic side-effects for the patient."
Human trials of the new drug are still some years away, but the Penn State researcher envisions a drug that could be delivered either intravenously to treat melanoma, or added to sunscreen lotion to prevent the disease.
The impact of a high-fat diet on the spread of cancer
Researchers at Purdue University have precisely measured the impact of a high-fat diet on the spread of cancer, finding that excessive dietary fat caused a 300 percent increase in metastasizing tumor cells in laboratory animals.
The researchers used an imaging technique to document how increasing fat content causes cancer cells to undergo changes essential to metastasis. Then they used another technique to count the number of cancer cells in the bloodstream of mice fed a high-fat diet compared to animals fed a lean diet.
The findings suggest that the combined tools represent a possible new diagnostic technique to determine whether a patient's cancer is spreading, said Ji-Xin Cheng, an assistant professor in Purdue's Weldon School of Biomedical Engineering and Department of Chemistry.
"It is generally accepted that diet and obesity are accountable for 30 percent of preventable causes of cancer, but nobody really knows why," Cheng said. "These findings demonstrate that an increase in lipids leads directly to a rise in cancer metastasis."
Researchers have theorized that tumor cells need more lipids than ordinary tissues to provide energy and material for tumor growth and metastasis.
"Before this work, however, most of the evidence was anecdotal, but here we present a mechanistic study," said Thuc T. Le, a National Institutes of Health postdoctoral fellow at Purdue who is working with Cheng.
Findings were detailed in a paper published on Jan. 30 in the journal BMC Cancer. The paper was written by Le; Terry B. Huff, a graduate research assistant in Purdue's Department of Chemistry; and Cheng. The research is supported by the Purdue Cancer Center.
The researchers implanted a cancerous lung tumor under the skin in each of the mice studied, and the animals were separated into two groups: one fed a high-fat diet and the other a lean diet.
The researchers then used an imaging method called coherent anti-Stokes Raman scattering, or CARS, to document how increasing lipids from fat intake induces changes to cancer cell membranes. Those changes, including processes called membrane phase separation and membrane rounding, enhance cancer metastasis.
"If the cancer cells don't have excess lipids they stick together and form very tight junctions in tumors, but increasing lipids causes them to take on a rounded shape and separate from each other," Le said.
The change in shape is critical to the ability of cancer cells to separate and spread throughout the body via the bloodstream.
The researchers then used another technique, called intravital flow cytometry, to count the number of cancer cells in the bloodstream of the mice. The technique works by shining a laser though the skin and into blood vessels, where the dyed cancer cells are visible.
Results showed the increase in lipids had no impact on the original tumors implanted in the mice. However, the rate of metastasis rose a dramatic 300 percent in the mice fed a high-fat diet.
The researchers later also examined the animals' lungs and counted the number of cancer cells that had migrated to the lungs as a result of metastasis. Those findings supported the other results showing increased metastasis in animals fed a high-fat diet.
The researches used the imaging and cell-counting tools to document that linoleic acid, which is predominant in polyunsaturated fats, caused increasing membrane phase separation, whereas oleic acid, found in monounsaturated fats, did not. Increased membrane phase separation could improve the opportunity of circulating tumor cells to adhere to blood vessel walls and escape to organs far from the original tumor site. The new findings support earlier evidence from other research that consuming high amounts of polyunsaturated fat may increase the risk of cancer spreading.
The findings suggest that combining CARS and intravital flow cytometry represents a possible new diagnostic tool to screen patients for cancer. The tool can be used to count lipid-rich tumor cells circulating in a patient's blood by shining a laser through the skin and into blood vessels. Because lipids can be detected without the need for dyes, the technique might be developed into a convenient method to diagnose whether a patient's cancer is spreading aggressively, Cheng said.
"These findings open the possibility of an entirely new, relatively simple method for diagnosing whether cancer is metastasizing," he said.
Future work will focus on not only how obesity increases metastasis but also how it might play a direct role in initiating the development of cancers.
Data Suggests a Diet High in Vegetable Intake Can Reduce Risk of Prostate Cancer
In the online edition of Molecular Nutrition and Food Research, Ruth Chan and collaborators provided a review on prostate cancer (CaP) and vegetable consumption. There is data that suggests a diet high in vegetable intake can reduce the risk of CaP. The primary mechanism of this protective vegetable effect is antioxidant protection against DNA and cell damage.
Available literature was identified for this review. Of the available studies, 29 were cohort studies, 69 case-control studies, and 4 randomized clinical trials. Highlights of this extensive review are presented herein. Tomatoes and their byproducts contain the carotenoid antioxidant lycopene. Two cohort studies reported tomatoes decreased CaP risk and 3 cohort studies reported a non-significant association. For case-control studies, 2 showed significant decreased risk and 5 showed a non-significant association. One study suggested that the potential benefit was greater in advanced as compared to localized CaP. Overall, studies for tomatoes and lycopenes show inconsistent results on decreasing CaP risk, but lycopene based foods are probably protective.
Yellow orange vegetables contain the antioxidant _-carotene. Data on _-carotene and CaP risk from cohort and case-control studies were inconclusive for a protective effect. Supplemental use of _-carotene was not shown to be protective. Flavonoids are a carbon structure compound ubiquitously present in plant foods and have anti-oxidative and anti-inflammatory properties. They may suppress angiogenesis, induction of apoptosis and down-regulation of hormone receptors expression. Overall there is some evidence suggesting that consumption of legumes, including soy and soy products, is protective against CaP.
Regarding vitamins, vitamin C has had limited study, but with the data available there is no evidence of a protective effect. Vitamin E is a naturally occurring fat-soluble vitamin found predominantly in plant foods and some animal foods. In a supplementation trial, there was suggestion that vitamin E was of benefit, but all the participants were smokers. Two other publications failed to show a benefit, and a preliminary report from the selenium and vitamin E trial does not suggest a benefit. As for allium vegetables which include garlic, onions, leeks, chives, scallions and shallots, while in vitro data suggest a protective benefit, population based studies are limited and a protective effect remains to be determined. Finally, cruciferous vegetables include broccoli, cauliflower Brussels sprouts, cabbage, bok choy, collard greens and kale. These are rich in sulforaphane and indole-3 carbinol, which have anticarcinogenic properties. To date, population-based studies are limited and a positive protective benefit remains to be determined.
Building Strong Bones: Running May Provide More Benefits Than Resistance Training, MU Study Finds
Osteoporosis affects more than 200 million people worldwide and is a serious public health concern, according to the National Osteoporosis Foundation. Resistance training often is recommended to increase and prevent loss of bone mineral density (BMD), although previous studies that examined the effects of resistance training in men produced varied results. Now, in a new study, University of Missouri researchers have found that high-impact activities, such as running, might have a greater positive effect on BMD than resistance training.
“The results of the study confirm that both resistance training and high-impact endurance activities increase bone mineral density. However, high-impact sports, like running, appear to have a greater beneficial effect,” said Pam Hinton, associate professor in the Department of Nutrition and Exercise Physiology in the MU College of Human Environmental Sciences.
According to the researchers, the true effects of weight-bearing or resistance exercise are only apparent when controlling for differences in body weight or composition. People who primarily perform non weight-bearing activities will benefit from resistance training that increases lean body mass, Hinton said. People who engage in activities, such as cycling, swimming, or rowing, should add bone-strengthening activities, such as resistance training or running, to their exercise regimens.
“Exercise programs to increase bone strength should be designed using what is known about how bones respond to exercise,” Hinton said. “Only the skeletal sites that experience increased stress from exercise will become stronger. For example, performing upper body resistance exercises will not increase bone mineral density of the hips. The response of bone to loading is determined by the magnitude of the force, and the rate and direction(s) at which it is applied. Therefore, high-impact, dynamic, multi-directional activities, including structured jump-training (plyometrics), result in greater gains in bone strength. Playing basketball, volleyball, or soccer are also good options.”
In the study, the researchers determined the effects of long-term running, cycling, and resistance training on whole-body and regional BMD, taking into account the effects of body weight and composition, in men ages 19 to 45. After adjusting for differences in lean body mass, the researchers found that runners had greater spine BMD than cyclists. Lean body mass was positively associated with BMD in both resistance-trained individuals and cyclists but not in runners; therefore, high-impact activity may override the benefits of lean body mass on BMD, Hinton said.
The study, “Lean body mass and weight-bearing activity in the prediction of bone mineral density in physically active men,” was published in the February issue of the Journal of Strength Conditioning.
New study shows how spikes in nitrite can have
(BOSTON) - A new study provides insight into how a short burst in nitrite can exert lasting beneficial effects on the heart, protecting it from stress and assaults such as heart attacks. In this study, just published in Circulation Research, researchers at Boston University School of Medicine have demonstrated for the first time that short elevations in circulating levels of this simple anion are sufficient to have a lasting impact on the heart by modulating its oxidation status and its protein machinery.
Nitrite, an oxidation product of the ubiquitous short-lived cell signaling molecule, nitric oxide (NO), was until recently thought to be biologically inert at the relatively low levels found in the body. Traces of nitrite are present in our diet and significant amounts are continuously produced from nitrate, another oxidation product of NO and a constituent of green, leafy vegetables. The suspicion that high levels of nitrite and nitrate may cause cancer, as well as concerns about their risk to compromise the ability of red blood cells to deliver oxygen to tissues, have led to strict regulations aimed at limiting our exposure to these substances through drinking water and food products.
In the past few years, however, multiple research groups have shown that low concentrations of nitrite exert numerous beneficial effects, ranging from anti-bacterial activities to increases in local blood flow, and that they can somehow protect tissues from damage when oxygen is suddenly cut off and then rapidly restored, as occurs during heart attacks and strokes.
To study the molecular underpinnings of this protective effect of nitrite, the researchers at Boston University School of Medicine used a rat model in which they administered nitrite only once, causing a short spike in circulating levels, as a way to simulate the types of naturally occurring increases in nitrite that follow exercise or consumption of a meal rich in nitrate.
The researchers used a systems-biology approach in which changes in multiple biological and biochemical systems (e.g., the composition of a large number of proteins, the concentration of several small molecule metabolites, and functional outcomes) are simultaneously monitored and then integrated to produce one final picture in order to provide a broader view of the impact of this treatment on the heart. They tested their theory that following these changes over time and at different doses of nitrite might help to explain the protective effects of nitrite on the heart.
"What we found was that a single brief nitrite treatment elicited persisting changes in the heart's oxidation status together with lasting alterations to numerous proteins involved in the heart's energy metabolism, redox regulation, and signaling," said David H. Perlman, a post-doctoral research associate in the Cardiovascular Proteomics Center at Boston University School of Medicine, and lead author of the study. "These alterations were particularly striking because they persisted at least 24 hours after the actual nitrite levels had returned back to normal, and they were correlated strongly with the improvements in heart function observed at the same time."
He noted that this type of protection, called 'cardiac preconditioning', is a recently discovered phenomenon shown to be caused by numerous pharmacological agents.
"The proteins we have implicated include some key proteins, such as mitochondrial aldehyde dehydrogenase, that have been shown by others to be critical to cardiac protection afforded by other agents and triggers," added Perlman. "This is exciting because it ties nitrite-triggered cardioprotection into the broader preconditioning field. Our study complements and extends other work, and identifies new players of potential importance for protection of the heart."
Perlman explained that nitrite levels in our bodies change under a number of circumstances, such as when we run up a flight of stairs or eat a big serving of salad.
"For years, the resulting bursts in nitrite were considered to be of little if any physiological relevance. Now we have good reason to believe that even small spikes in nitrite concentration can alter protein function in the heart in ways that afford protection," noted Perlman.
"We are intrigued by the breadth and magnitude of the proteomic changes in heart mitochondria elicited by a single, short-lasting elevation in nitrite concentration and believe that our findings will have broad implications for mitochondrial signalling and cardiac energetics," commented Martin Feelisch, senior author of the study. "It looks as though nitrite is triggering an ancient program aimed at fine-tuning mitochondrial function. Although the present study focussed on the heart, our observations may extend to other tissues and translate into relevant changes in muscle function elsewhere. If true, this may help explain, for example, the training effects of very short periods of exercise, which are known to be associated with elevations in circulating nitrite concentrations."
Interestingly, only low and high doses of nitrite, but not those in-between, were found to be protective. Although further studies will be needed to fully delineate the mechanisms of nitrite-induced cardioprotection, this study informs ongoing basic and translational studies by highlighting the importance of the dose-effect relationship for nitrite and the broad array of downstream targets possibly involved in its cardioprotective efficacy, the researchers concluded.
Health campaigns that promote exercise may cause people to eat more
New research from the University of Illinois suggests that campaigns that promote exercise may actually cause people to eat more.
People who viewed posters suggesting that they "join a gym" or "take a walk" ate more food after looking at the posters than people who saw similarly designed posters prompting them to "make friends" or "be in a group," the researchers found.
Subliminal words about being active had a similar effect on study participants, said psychology professor Dolores Albarracín, who led the research.
"Viewers of the exercise messages ate significantly more (than their peers, who viewed other types of messages)," she said. "They ate one-third more when exposed to the exercise ads." Those exposed to subliminal words about activity during a computer task ate about 20 percent more than those exposed to neutral words, she said.
The study, which appears in the journal Obesity, builds on previous research by Albarracín that suggests that general messages to be active can prompt people to behave in a variety of ways, some of which may have negative consequences.
Those designing public health campaigns are in the habit of trying to change one behavior at a time, Albarracín said. They should be aware that "whatever they communicate is likely to influence not only the behavior they had in mind but other behaviors that might be somewhat remotely linked," she said.
Teenage boys who eat fish at least once a week achieve higher intelligence scores
Fifteen-year-old males who ate fish at least once a week displayed higher cognitive skills at the age of 18 than those who it ate it less frequently, according to a study of nearly 4,000 teenagers published in the March issue of Acta Paediatrica.
Eating fish once a week was enough to increase combined, verbal and visuospatial intelligence scores by an average of six per cent, while eating fish more than once a week increased them by just under 11 per cent.
Swedish researchers compared the responses of 3,972 males who took part in the survey with the cognitive scores recorded in their Swedish Military Conscription records three years later.
"We found a clear link between frequent fish consumption and higher scores when the teenagers ate fish at least once a week" says Professor Kjell Torén from the Sahlgrenska Academy at the University of Gothenburg, one of the senior scientists involved in the study. "When they ate fish more than once a week the improvement almost doubled.
"These findings are significant because the study was carried out between the ages of 15 and 18 when educational achievements can help to shape the rest of a young man's life."
The research team found that:
0. 58 per cent of the boys who took part in the study ate fish at least once a week and a further 20 per cent ate fish more than once a week.
0.
0. When male teenagers ate fish more than once a week their combined intelligence scores were on average 12 per cent higher than those who ate fish less than once a week. Teenagers who ate fish once a week scored seven per cent higher.
0.
0. The verbal intelligence scores for teenagers who ate fish more than once a week were on average nine per cent higher than those who ate fish less than once a week. Those who ate fish once a week scored four per cent higher.
0.
0. The same pattern was seen in the visuospatial intelligence scores, with teenagers who ate fish more than once a week scoring on average 11 per cent higher than those who ate fish less than once a week. Those who ate fish once a week scored seven per cent higher.
0.
"A number of studies have already shown that fish can help neurodevelopment in infants, reduce the risk of impaired cognitive function from middle age onwards and benefit babies born to women who ate fish during pregnancy" says Professor Torén.
"However we believe that this is the first large-scale study to explore the effect on adolescents."
The exact mechanism that links fish consumption to improved cognitive performance is still not clear.
"The most widely held theory is that it is the long-chain polyunsaturated fatty acids found in fish that have positive effects on cognitive performance" explains Professor Torén.
"Fish contains both omega-3 and omega-6 fatty acids which are known to accumulate in the brain when the foetus is developing. Other theories have been put forward that highlight their vascular and anti-inflammatory properties and their role in suppressing cytokines, chemicals that can affect the immune system."
In order to isolate the effect of fish consumption on the study subjects, the research team looked at a wide range of variables, including ethnicity, where they lived, their parents' educational level, the teenagers' well-being, how frequently they exercised and their weight.
"Having looked very carefully at the wide range of variables explored by this study it was very clear that there was a significant association between regular fish consumption at 15 and improved cognitive performance at 18" concludes lead author Dr Maria Aberg from the Centre for Brain Repair and Rehabilitation at the University of Gothenburg.
"We also found the same association between fish and intelligence in the teenagers regardless of their parents' level of education."
The researchers are now keen to carry out further research to see if the kind of fish consumed - for example lean fish in fish fingers or fatty fish such as salmon - makes any difference to the results.
"But for the time being it appears that including fish in a diet can make a valuable contribution to cognitive performance in male teenagers" says Dr Aberg.
Go green for healthy teeth and gums
Recent study suggests that antioxidants in green tea may help reduce periodontal disease
With origins dating back over 4,000 years, green tea has long been a popular beverage in Asian culture, and is increasingly gaining popularity in the United States. And while ancient Chinese and Japanese medicine believed green tea consumption could cure disease and heal wounds, recent scientific studies are beginning to establish the potential health benefits of drinking green tea, especially in weight loss, heart health, and cancer prevention. A study recently published in the Journal of Periodontology, the official publication of the American Academy of Periodontology (AAP), uncovered yet another benefit of green tea consumption. Researchers found that routine intake of green tea may also help promote healthy teeth and gums. The study analyzed the periodontal health of 940 men, and found that those who regularly drank green tea had superior periodontal health than subjects that consumed less green tea.
"It has been long speculated that green tea possesses a host of health benefits," said study author Dr. Yoshihiro Shimazaki of Kyushu University in Fukuoka, Japan. "And since many of us enjoy green tea on a regular basis, my colleagues and I were eager to investigate the impact of green tea consumption on periodontal health, especially considering the escalating emphasis on the connection between periodontal health and overall health."
Male participants aged 49 through 59 were examined on three indicators of periodontal disease: periodontal pocket depth (PD), clinical attachment loss (CAL) of gum tissue, and bleeding on probing (BOP) of the gum tissue. Researchers observed that for every one cup of green tea consumed per day, there was a decrease in all three indicators, therefore signifying a lower instance of periodontal disease in those subjects who regularly drank green tea.
Green tea's ability to help reduce symptoms of periodontal disease may be due to the presence of the antioxidant catechin. Previous research has demonstrated antioxidants' ability to reduce inflammation in the body, and the indicators of periodontal disease measured in this study, PD, CAL and BOP, suggest the existence of an inflammatory response to periodontal bacteria in the mouth. By interfering with the body's inflammatory response to periodontal bacteria, green tea may actually help promote periodontal health, and ward off further disease. Periodontal disease is a chronic inflammatory disease that affects the gums and bone supporting the teeth, and has been associated with the progression of other diseases such as cardiovascular disease and diabetes.
"Periodontists believe that maintaining healthy gums is absolutely critical to maintaining a healthy body," says Dr. David Cochran, DDS, PhD, President of the AAP and Chair of the Department of Periodontics at the University of Texas Health Science Center at San Antonio. "That is why it is so important to find simple ways to boost periodontal health, such as regularly drinking green tea – something already known to possess certain health-related benefits."
1 in 7 U.S. Teens Is Vitamin D Deficient
Weill Cornell Medical College Study Finds Prevalence Highest Among African-Americans
One in seven American adolescents is vitamin D deficient, according to a new study by researchers in the Department of Public Health at Weill Cornell Medical College. The findings are published in the March issue of the journal Pediatrics and were presented at the Pediatric Academic Societies' Annual Meeting in May 2008.
In children, vitamin D deficiency can interfere with bone mineralization, leading to rickets. In adults, it is linked to cardiovascular disease, cancer, diabetes, immune dysfunction and hypertension.
The study employs a new definition of vitamin D deficiency recommended by a group of scientists attending the 13th Workshop Consensus for Vitamin D Nutritional Guidelines in 2007. These experts collectively proposed that the minimum acceptable serum vitamin D level be raised from 11 nanograms per milliliter (ng/mL) to at least 20 ng/mL.
Using the newer criteria, the study finds more than half of African-American teens are vitamin D deficient. Girls had more than twice the risk of deficiency compared with boys. And overweight teens had nearly double the risk of their normal-weight counterparts.
"These are alarming findings. We need to do a better job of educating the public on the importance of vitamin D, and the best ways to get it. To meet minimum nutritional requirements teens would need to consume at least four glasses of fortified milk daily or its dietary equivalent. Other foods rich in vitamin D include salmon, tuna, eggs and fortified cereals. A vitamin supplement containing 400 IU of vitamin D is another alternative," says Dr. Sandy Saintonge, assistant professor of clinical pediatrics and assistant professor of clinical public health at Weill Cornell Medical College, and a pediatric emergency physician at New York Hospital Queens, a member of the NewYork-Presbyterian Hospital Healthcare System. "We should also consider a national fortification strategy, perhaps including routine supplementation and monitoring of serum levels, but more research is needed to determine optimal vitamin D levels."
Of the specific findings, the authors were particularly concerned about the role of weight in deficiency. "Because vitamin D is stored in body fat, simply increasing the dosage of vitamin D may not be effective in overweight adolescents," notes senior author Dr. Linda M. Gerber, professor of public health in the Division of Biostatistics and Epidemiology and professor of epidemiology in medicine at Weill Cornell Medical College. "As the prevalence of childhood obesity increases, vitamin D deficiency may increase as well. In this group, appropriate nutrition could solve both problems."
Another concern is the increased risk of deficiency in girls, some of whom may become pregnant during adolescence. The authors note that a lack of vitamin D may increase maternal risk of preeclampsia and gestational diabetes and may be associated with reduced bone mineralization in the offspring.
Data was obtained from National Health and Nutrition Examination Survey III, a cross-sectional survey administered to a nationally representative sample of persons aged 2 months and older. Analyses were restricted to 2,955 participants aged 12 to 19.
Low vitamin D levels associated with several risk factors in teenagers
Study highlights:
• Low levels of vitamin D were associated with increased risk of high blood pressure, high blood sugar and metabolic syndrome in teenagers.
• The highest levels of vitamin D were found in whites, the lowest levels in blacks and intermediate levels in Mexican-Americans.
Low levels of vitamin D were associated with an increased risk of high blood pressure, high blood sugar and metabolic syndrome in teenagers, researchers reported at the American Heart Association’s 49th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.
In the study, researchers analyzed 3,577 adolescents, 12 to 19 years old (51 percent boys), who participated in the nationally representative National Health and Nutrition Examination Survey (NHANES) conducted from 2001–2004.
After adjusting for age, sex, race/ethnicity, body mass index, socioeconomic status and physical activity, researchers found the adolescents with the lowest levels of vitamin D were:
• 2.36 times more likely to have high blood pressure;
• 2.54 times more likely to have high blood sugar; and
• 3.99 times more likely to have metabolic syndrome.
Metabolic syndrome is a cluster of cardiovascular disease and diabetes risk factors including elevated waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or “good”) cholesterol and high fasting glucose levels. The presence of three or more of the factors increases a person’s risk of developing diabetes and cardiovascular disease.
“We showed strong associations between low levels of vitamin D and higher risk of high blood pressure, hyperglycemia and metabolic syndrome among adolescents, confirming the results of studies among adults,” said Jared P. Reis, Ph.D., the study’s lead author and post-doctoral research fellow at Johns Hopkins Bloomberg School of Public Health in Baltimore.
Researchers used a biomarker of vitamin D to measure levels in blood. The biomarker measures vitamin D obtained from food, vitamin supplementation and exposure to sunlight.
The ethnic breakdown was similar to the general U.S. population: 64.7 percent non-Hispanic whites; 13.5 percent non-Hispanic blacks; and 11 percent Mexican Americans.
The study highlights the association between high levels of vitamin D and lower risk of heart disease. The highest levels of vitamin D were found in whites, the lowest levels in blacks and intermediate levels in Mexican Americans. Whites had almost twice as high levels as blacks.
In whites, the average level of vitamin D was 28.0 nanograms per milliliter (ng/mL); in blacks, 15.5 ng/mL; and in Mexican Americans, 21.5 ng/mL.
“Although our study is important, we believe clinical trials designed to determine the effects of vitamin D supplementation on the risk of heart disease risk factors in adolescents should be conducted before recommendations can be made for vitamin D in the prevention of cardiovascular disease,” Reis said.
The Institute of Medicine recommends a daily intake of vitamin D of 200 International Units (IU) for those less than 50 years, which includes children and adolescents. More recent recommendations, however, from the American Academy of Pediatrics suggests a daily intake of 400 IU daily. While these intakes have been shown to be important in the prevention of skeletal conditions such as rickets in children and osteoporosis in adults, some specialists have suggested intakes of at least 1,000 IU daily may be needed for overall health.
Low levels of vitamin D are strongly associated with overweight and abdominal obesity. Since vitamin D is a fat-soluble vitamin, it may be sequestered within adipose tissue. This may explain why those who are obese are more likely to be vitamin D deficient, Reis said.
Vitamin D plays a useful role in general human health, particularly in bone health. Other roles are emerging, Reis said. “This is an exciting time; since we are just now beginning to understand the role that vitamin D may play in cardiovascular health.”
“These data on serum vitamin D levels in young people raise some concern about their food choices and even the amount of time they spend in the sunshine,” said Robert H. Eckel, M.D., American Heart Association past president. “The American Heart Association recommends an overall healthy diet and lifestyle, and that people get their nutrients primarily from food sources rather than supplements.”
Not enough vitamin D in the diet could mean too much fat on adolescents
Too little vitamin D could be bad for more than your bones; it may also lead to fatter adolescents, researchers say.
A Medical College of Georgia study of more than 650 teens age 14-19 has found that those who reported higher vitamin D intakes had lower overall body fat and lower amounts of the fat in the abdomen, a type of fat known as visceral fat, which has been associated with health risks such as heart disease, stroke, diabetes and hypertension.
The group with the lowest vitamin D intake, black females, had higher percentages of both body fat and visceral fat, while black males had the lowest percentages of body and visceral fat, even though their vitamin D intake was below the recommended levels. Only one group – white males – was getting the recommended minimum intake of vitamin D.
“This study was a cross-section so, while it cannot prove that higher intake of vitamin D caused the lower body fat, we know there is a relationship that needs to be explored further," says Dr. Yanbin Dong, a molecular geneticist and cardiologist at the MCG Gerogia Prevention Institute.
Dr. Dong, who also co-directs the MCG Diabetes & Obesity Discovery Institute, and Inger Stallman-Jorgensen, a research dietician at the GPI, present their findings this week at the American Heart Association’s Joint 49th Conference on Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism in Palm Harbor, Fla.
The pair will next study whether it is feasible for teens to take a daily vitamin D supplement in pill form. Those results will help them design a larger study to explore the relationship between vitamin D intake and body fat levels in teens.
“We already know that encouraging teens to get an adequate amount of vitamin D in their diets will help promote a healthy body as they grow and develop,” Ms. Stallman-Jorgensen says. “Now we need to do intervention studies where we give teens vitamin D supplements to determine if there is a cause and effect relationship between vitamin D intake and fat.”
The American Academy of Pediatrics recommends adolescents get at least 400 units of vitamin D per day – either from milk or sun exposure. There are typically 100 units in one 8-ounce glass of whole milk. The recommended daily dose from the sun would require at least 30 minutes of adequate exposure to direct sunlight two or three times a week at peak hours, between noon and 3 p.m.
Ms. Stallman-Jorgensen said there are many reasons teens don't get enough vitamin D, which has been linked to the prevention of diabetes, cancer and cardiovascular disease.
“As humans, our largest source of vitamin D should be the sun. But we don’t spend enough time outdoors to get enough sun exposure and when we do, we’re often covered up and wearing sunscreen," she said. "We can get vitamin D from certain foods, like fatty fish and liver, but it’s not in a lot of foods that we commonly consume. In this country, our milk is fortified with vitamin D. Unfortunately, teens just don’t drink enough milk to get their daily requirements.”
She points out that low sunlight during the winter months reduces the amount of vitamin D the skin produces, and that darker-skinned people obtain less vitamin D from the sun because the extra melanin in their skin filters out more sunlight.
Some people can't tolerate milk because they lack the enzyme that processes lactose, the natural sugar in milk, though "most people can handle it in small amounts,” Ms. Stallman says.
Cultural issues may also be at play, Ms. Stallman-Jorgensen says.
“Most teens want to drink sodas and sugary drinks. It’s not cool to drink milk – they think of it as more of a food for babies,” she said.
Potential study participants had their weekday and weekend diets tracked by researchers seven times during a three-month period. Those who provided at least four diet reports were included in the final group of 659.
Body fat percentages were measured by dual energy X-ray absorptiometry scans, which can measure total body composition. Visceral fat was measured in a subset of 432 teens.
Long-Term Use Of Nutrient Supplements May Increase Cancer Risk
Long-term use of beta carotene and some other carotenoid-containing dietary supplements may increase the risk of lung cancer, especially among smokers, according to a study by University of North Carolina at Chapel Hill researchers. The study, which also examined use of retinol, vitamin A, lycopene and lutein, appears in the February issue of the American Journal of Epidemiology.
Researchers used questionnaires to assess use of dietary supplements, including multi-vitamins and individual nutrients, by more than 77,000 Americans over 10 years, and matched the results against data from the Surveillance, Epidemiology and End Results (SEER) cancer registry to track the rates of lung cancer among them.
They found that certain people – especially smokers – who took dietary supplements containing these nutrients, were at higher risk of developing lung cancer than the general population.
“In the 1980s, studies began showing the link between diet and cancers, and showing that eating fruits and vegetables could lower your risk of certain cancers, including lung cancer,” said Jessie Satia, Ph.D., associate professor of epidemiology and nutrition at the UNC Gillings School of Global Public Health and member of UNC’s Lineberger Comprehensive Cancer Center. “Scientists wondered, then, if you took the beneficial nutrients from fruits and vegetables and gave high doses of them to persons at high risk for lung cancer, such as smokers, if you could decrease the risk of lung cancer.”
However, subsequent clinical trials proved that high doses of beta carotene actually seemed to increase the risk of developing lung cancer, Satia said, and trials in the United States and Sweden were stopped when the increased risk was detected.
“But that was in clinical trials, under controlled circumstances,” Satia said. “We wanted to see if the same results would be found if we looked at use of these supplements in the general population.”
Satia and colleagues from UNC and the University of Washington in Seattle gave questionnaires to men and women, aged 50 to 76, in western Washington state. Participants were asked about their use of multivitamins and individual nutrient supplements over the past 10 years (including frequency and dose), as well as about their health history and risk factors. Participants were followed for the next four years, at which time lung cancer rates were obtained.
The results show that smokers’ risk of developing lung cancer increased with the length of time they took dietary supplements containing beta carotene, retinol and lutein.
“The risk increased the longer the person had taken the supplements,” Satia said. “The amount of time the person took supplements seemed to have a greater effect than the dose. Even a modest dose, if taken for a long time, can increase the risks of lung cancer, especially among smokers.”
For example, the study found that use of retinol and lutein supplements for four years or longer was associated with increases in lung cancer risk of 53 percent and 102 percent, respectively.
The risk for nonsmokers could not be determined because lung cancer cases among nonsmokers was small, Satia said.
“We believe beta-carotene is an antioxidant, but it seems that if you take too much, at some point it can have pro-oxidant effects, which can result in elevated cancer risk.”
Vitamin C intake associated with lower risk of gout in men
Men with higher vitamin C intake appear less likely to develop gout, a painful type of arthritis, according to a report in the March 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
"Gout is the most common type of inflammatory arthritis in men," the authors write as background information in the article. "Epidemiologic studies suggest that the overall disease burden of gout is substantial and growing. The identification of the risk factors for gout that are modifiable with available measures is an important first step in the prevention and management of this common and excruciatingly painful condition."
Hyon K. Choi, M.D., Dr.P.H., then of University of British Columbia, Vancouver, and now of Boston University School of Medicine, and colleagues examined the relationship between vitamin C intake and gout in 46,994 men between 1986 and 2006. Every four years, the men completed a dietary questionnaire, and their vitamin C intake through food and supplements was computed. Every two years, participants reported whether they had been diagnosed with or developed symptoms of gout.
During 20 years of follow-up, 1,317 men developed gout. Compared with men who had a vitamin C intake of less than 250 milligrams per day, the relative risk of gout was 17 percent lower for those with a daily intake of 500 to 999 milligrams, 34 percent lower for those with an intake of 1,000 to 1,499 milligrams per day and 45 percent lower for those with an intake of 1,500 milligrams per day or higher. For every 500-milligram increase in their vitamin C intake, men's risk for gout appeared to decrease by 17 percent. Compared with men who did not take vitamin C supplements, those who took 1,000 to 1,499 supplemental milligrams per day had a 34 percent lower risk of gout and those who took 1,500 supplemental milligrams per day had a 45 percent lower risk.
Vitamin C appears to reduce levels of uric acid in the blood, the authors note; a buildup of this naturally occurring compound can form crystal deposits in and around joints, leading to the pain, inflammation and swelling associated with gout. Vitamin C may affect reabsorption of uric acid by the kidneys, increase the speed at which the kidneys work or protect against inflammation, all of which may reduce gout risk, the authors note.
"Given the general safety profile associated with vitamin C intake, particularly in the generally consumed ranges as in the present study (e.g., tolerable upper intake level of vitamin C of less than 2,000 milligrams in adults according to the Food and Nutrition Board, Institute of Medicine), vitamin C intake may provide a useful option in the prevention of gout," they conclude.
Drinking wine lowers risk of Barrett's esophagus, precursor to nation's fastest growing cancer
Kaiser Permanente study is first & largest to examine connection between alcohol & Barrett's esophagus
Drinking one glass of wine a day may lower the risk of Barrett's Esophagus by 56 percent, according to a new study by the Kaiser Permanente Division of Research in the March issue of Gastroenterology. Barrett's Esophagus is a precursor to esophageal cancer, the nation's fastest growing cancer with an incidence rate that's jumped 500 percent in the last 30 years.
Barrett's Esophagus affects 5 percent of the population and occurs when heartburn or acid reflux permanently damages the esophageal lining. People with Barrett's Esophagus have a 30- to 40-fold higher risk of developing esophageal adenocarcinoma (a type of esophageal cancer) because the Barrett's Esophagus cells can grow into cancer cells.
Because there are no symptoms or warning signs of Barrett's Esophagus, people discover they have Barrett's Esophagus when an endoscopy for anemia, heartburn or a bleeding ulcer reveals esophageal cells that were damaged, then changed form during the healing process. Currently nothing can be done to treat Barrett's Esophagus; it can only be monitored.
This is the first and largest population-based study to examine the connection between alcohol consumption and risk of Barrett's Esophagus. Funded in part by the National Institutes of Health, the Kaiser Permanente study looked at 953 men and women in Northern California between 2002 and 2005 and found that people who drank one or more glasses of red or white wine a day had less than half the risk (or 56 percent reduced risk) of Barrett's Esophagus. There was no reduction of Barrett's Esophagus risk among people who drank beer or liquor.
"The rate of esophageal adenocarcinoma in this country is skyrocketing yet very little is known about its precursor, Barrett's Esophagus. We are trying to figure out how to prevent changes that may lead to esophageal cancer." said Douglas A. Corley, MD, a Kaiser Permanente gastroenterologist and the study's principal investigator.
The study findings are echoed by two other studies published in the same issue of the Gastroenterology journal: Australian researchers found that people who drank wine were at a lower risk of esophageal adenocarcinoma, and Irish researchers found that people who drank wine were at a lower risk for esophagitis, an irritation of the esophagus that follows chronic heartburn and often precedes Barrett's Esophagus and cancer.
Researchers are not certain why wine reduces the risk of Barrett's Esophagus and esophageal cancer. One theory is that the wine's antioxidants neutralize the oxidative damage caused by gastroesophageal reflux disease, a risk factor for Barrett's Esophagus. Another theory is that wine drinkers typically consume food with their wine as opposed to drinking straight liquor without food, thereby reducing the potentially damaging effect of alcohol on esophageal tissue, said Ai Kubo, MD, an epidemiologist at Kaiser Permanente and lead author on the study. "But we cannot preclude the possibility that wine drinking is a proxy for other 'health-seeking' behavior," Kubo added.
This study is part of larger, case-controlled Kaiser Permanente study led by Dr. Corley that looked at abdominal obesity and consumption of dietary antioxidants, fruits and vegetables in connection with Barrett's Esophagus. It found that people can reduce their risk of Barrett's Esophagus by eating eight servings of fruits and vegetables a day and maintaining a normal body weight.
"My advice to people trying to prevent Barrett's Esophagus is: keep a normal body weight and follow a diet high in antioxidants and high in fruits and vegetables," Corley said. "We already knew that red wine was good for the heart, so perhaps here is another added benefit of a healthy lifestyle and a single glass of wine a day."
Researchers noted, though, that the protective effect of wine in terms of preventing Barrett's Esophagus was greatest with just one or two glasses a day. The protective effect of wine did not increase with higher consumption.
"It's not actually clear that treating the acid reflux will necessarily prevent getting someone from getting Barrett's Esophagus," said Dr. Corley. "The best way to prevent reflux is to maintain a normal weight."
Moderate alcohol intake associated with bone protection
Epidemiological study examines effects of beer, wine and liquor on BMD
In an epidemiological study of men and post-menopausal women primarily over 60 years of age, regular moderate alcohol intake was associated with greater bone mineral density (BMD). Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University found associations were strongest for beer and wine and, importantly, BMD was significantly lower in men drinking more than two servings of liquor per day. The results suggest that regular moderate consumption of beer or wine may have protective effects on bone, but that heavy drinking may contribute to bone loss.
"Previous research suggests that moderate alcohol consumption in older men and post-menopausal women may protect against BMD loss, a major risk factor for osteoporosis," said Katherine L. Tucker, PhD, corresponding author and director of the Dietary Assessment and Epidemiology Research Program at the USDA HNRCA. The 2005 Dietary Guidelines issued by the federal government defines moderate alcohol consumption as one drink per day for women and two drinks per day for men.
"Our study also looks at the possible effects of the three alcohol classes, beer, wine and liquor on BMD," Tucker continued. "We saw stronger associations between higher BMD and beer drinkers, who were mostly men, and wine drinkers, who were mostly women, compared to liquor drinkers." The results were published online February 25 by the American Journal of Clinical Nutrition.
Tucker, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts, and colleagues analyzed BMD measurements taken at three hip sites and the lumbar spine in 1,182 men, 1,289 post-menopausal women, and 248 pre-menopausal women whose parents or in-laws participated in the original Framingham Heart Study. There was not enough data to determine the effects of more than two servings of alcohol per day in post-menopausal women or the effects of daily alcohol consumption on BMD in pre-menopausal women. Participants self-reported their alcohol intake on dietary questionnaires. One serving of beer equaled a glass, bottle or can (356 mL), one serving of wine equaled a 4-oz. glass (118 mL), and one serving of liquor equaled one mixed drink or shot (42 mL).
After adjusting for several other factors that may have accounted for the higher BMD, such as silicon intake, calcium intake and smoking history, the authors still saw an association between higher BMD and moderate alcohol consumption. One of the strongest associations was seen in men who reported consuming one or two servings of total alcohol (a combination of beer, wine and liquor) or one or two servings of beer per day. Hip BMD in this group was significantly greater compared to non-drinkers.
In contrast, the authors observed significantly lower BMD at the hip and spine in men who consumed more than two servings of liquor per day compared to men who consumed one or two servings of liquor per day. "There is a body of research showing alcoholism is devastating to bones," Tucker said. "It's a major risk factor for osteoporosis. No one should depend solely on alcohol to maintain bone health."
The authors hypothesize that the silicon found in beer is contributing to the higher BMD scores in the men who reported consuming one or two servings of total alcohol or beer per day, citing previous studies finding silicon has greater bioavailability as a liquid. It is less clear why liquor and wine might protect BMD.
"We cannot say definitively what component of these alcoholic drinks might be beneficial to bone health because our findings are from an observational study, as opposed to a clinical trial," Tucker said. "Future studies might dig deeper into patterns of alcohol consumption, as we relied on a self-reported dietary questionnaire. Another component of data worthy of exploration is whether the antioxidants found in wine, such as revesterol or polyphenols, have a protective effect on bone in addition to other health benefits."
Georgetown researcher: 2 or more drinks a day may increase pancreatic cancer risk
Men and women who consume two or more alcoholic drinks a day could increase their risk of developing pancreatic cancer, according to a study published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
Previous studies have been unable to confirm the association between drinking and the risk of pancreatic cancer, but most studies depended on a person's recall of alcohol intake. Still, many hypothesize about the relationship between alcohol and pancreatic cancer because drinking is associated with the risk of pancreatitis and diabetes, and both of these conditions are known risk factors for developing the disease.
Unlike the previous studies, this current research pools data collected prospectively from 14 research studies, which included 862,664 individuals (319,716 men and 542,948 women). Data collected prospectively means information about dietary and environmental exposures were collected prior to diagnosis with pancreatic cancer. Researchers identified 2,187 individuals diagnosed with pancreatic cancer during the study.
"This is one of the largest studies ever to look at dietary factors in relation to pancreatic cancer risk," says lead author Jeanine M. Genkinger, Ph.D., an assistant professor at Georgetown University's Lombardi Comprehensive Cancer Center.
If individuals consumed 30 or more grams of alcohol per day (approximately two drinks), compared with no alcohol per day, their risk of pancreatic cancer was slightly increased, researchers said. A drink is defined as 12 ounces of beer, four ounces of wine, or 1.5 ounces of 80-proof distilled liquor.
Although, there was no statistically significant difference between men and women when comparing alcohol intake with risk of pancreatic cancer, the association was seen in women at two or more drinks per day. Comparatively, the researchers observed a higher risk among men who consumed three or more drinks a day.
No difference was observed by type of alcohol when comparing beer, distilled liquor or wine, according to Genkinger.
"Despite being a deadly disease, there are few known risk factors for developing pancreatic cancer," explains Genkinger. "At this point, it's important to understand any protective or risk factors for this dangerous disease even if the risks are weak or modest."
Red wine vs. white? It makes no difference when it comes to breast-cancer risk
The largest study of its kind to evaluate the effect of red versus white wine on breast-cancer risk concludes that both are equal offenders when it comes to increasing breast-cancer risk. The results of the study, led by researchers at Fred Hutchinson Cancer Research Center, were published in the March issue of Cancer Epidemiology, Biomarkers and Prevention.
"We were interested in teasing out red wine's effects on breast-cancer risk. There is reason to suspect that red wine might have beneficial effects based on previous studies of heart disease and prostate cancer," said lead author Polly Newcomb, Ph.D., M.P.H., head of the Cancer Prevention Program in the Public Health Sciences Division at the Hutchinson Center. "The general evidence is that alcohol consumption overall increases breast-cancer risk, but the other studies made us wonder whether red wine might in fact have some positive value."
Instead, Newcomb and colleagues found no compelling reason to choose Chianti over Chardonnay.
"We found no difference between red or white wine in relation to breast-cancer risk. Neither appears to have any benefits," Newcomb said. "If a woman drinks, she should do so in moderation – no more than one drink a day. And if a woman chooses red wine, she should do so because she likes the taste, not because she thinks it may reduce her risk of breast cancer," she said.
The researchers found that women who consumed 14 or more drinks per week, regardless of the type (wine, liquor or beer), faced a 24 percent increase in breast cancer compared with non-drinkers.
For the study, the researchers interviewed 6,327 women with breast cancer and 7,558 age-matched controls about their frequency of alcohol consumption (red wine, white wine, liquor and beer) and other breast-cancer risk factors, such as age at first pregnancy, family history of breast cancer and postmenopausal hormone use. The study participants, ages 20 to 69, were from Wisconsin, Massachusetts and New Hampshire. The frequency of alcohol consumption was similar in both groups, and equal proportions of women in both groups reported consuming red and white wine.
My reactions to new research – I will stay away from multi-vitamins, continue to drink red wine in moderation, keep drinking green tea.
Folic Acid Supplements Linked To Higher Risk Of Prostate Cancer
A study led by researchers at the University of Southern California (USC) found that men who took a daily folic acid supplement of 1 mg daily had more than twice the risk of prostate cancer compared with men who took a placebo.
The finding came from a secondary analysis of the Aspirin/Folate Polyp Prevention Study (AFPP), a placebo-controlled randomized trial to determine the impact of aspirin and folic acid on colon polyps in men and women who were at high risk for the disease. The results appear in the March 10 online issue of the Journal of the National Cancer Institute.
Folic acid (folate) is a B vitamin found in many vegetables, beans, fruits and whole grains. While evidence of its ability to reduce neural tube defects in infants while taken by the mother before or during pregnancy has been well documented, its effects on other conditions are unclear.
“We know that adequate folate levels are important in the prevention of several cancer types, cardiovascular and neurological diseases,” says lead author Jane Figueiredo, Ph.D., assistant professor of preventive medicine at the Keck School of Medicine of USC. “However, little has been known about its role in prostate cancer. Our objective was to investigate the relationship between folic acid supplements and dietary folate and risk of prostate cancer.”
The AFPP study was conducted between 1994 and 2006 and found that aspirin reduced the risk of colon polyps while folic acid had a negative effect and increased the risk of advanced and multiple polyps. The first analysis did not address the impact of folic acid supplements on prostate cancer risk. Previous observational studies have been inconsistent. Some studies suggest that increased folate in the diet or in supplements might actually lower the risk of prostate cancer, and others have suggested no effect or even a potential harmful effect.
In the secondary analysis, researchers looked at prostate cancer incidence among 643 men who were randomly assigned to 1 mg daily folic acid supplements or placebo in the AFPP study and who enrolled in an extended follow-up study. The estimated prostate cancer risk was 9.7 percent at 10 years in men assigned to folate, compared with 3.3 percent in men assigned to placebo.
By contrast, dietary folate intake and plasma folate showed a trend toward reduced risk of prostate cancer, although the difference did not reach statistical significance. It remains unclear why dietary and circulating folate among non-multivitamin users may be inversely associated with risk, Figueiredo says.
“The synthetic form of folate, folic acid, found in supplements, is more bioavailable compared to folate from dietary sources and we know the amount of folate available is critical,” she says. “Adequate levels of folate may be beneficial, but too much folate is unlikely to be beneficial.”
Alternatively, these results may be due to chance, and replication by other studies is needed, she notes.
“These findings highlight the potentially complex role of folate in prostate cancer. The possibility of different effects from folic acid-containing supplements versus natural sources of folate definitely merits further investigation.”
Aspirin Improves Survival in Women with Stable Heart Disease, According to WHI Study
Less Than One-Half Report Regular Aspirin Use
New results from the Women’s Health Initiative (WHI) Observational Study provide additional evidence that aspirin may reduce the risk of death in postmenopausal women who have heart disease or who have had a stroke. Jacques Rossouw, M.D., chief of the Women’s Health Initiative Branch at the National Heart, Lung, and Blood Institute (NHLBI), is available to comment on these findings. NHLBI, part of the National Institutes of Health, funded the research.
The study also provides new insight into aspirin dosing for women, suggesting that a lower dose of aspirin (81 milligrams, or mg) is as effective as a higher dose (325 mg). This is good news for women who might be concerned with internal bleeding, a well-known risk of aspirin that may be more likely with higher doses of aspirin, according to other studies. However, randomized clinical trials are needed to determine the optimal doses of aspirin in women with cardiovascular disease.
“Aspirin Use, Dose, and Clinical Outcomes in Postmenopausal Women with Stable Cardiovascular Disease – The Women’s Health Initiative Observational Study,” appears in the March issue of the journal Circulation: Cardiovascular Quality and Outcomes and was published online March 5, 2009.
Scientific evidence indicates that, in general, aspirin lowers the risk of death and incidence of heart attack and stroke in patients with a history of cardiovascular disease; however, the benefits of aspirin in women with stable cardiovascular disease in particular are unknown. In this study, researchers analyzed data from 8,928 postmenopausal women who had previously had a heart attack, stroke or transient ischemic attack (TIA, or mini-stroke), angina, or angioplasty or coronary bypass surgery to improve blood flow. Participants were followed for an average of 6.5 years.
Compared to those who did not report taking aspirin, regular aspirin users had a 25 percent lower risk of death from cardiovascular disease and a 14 percent lower risk of death from any cause. Overall, aspirin use did not significantly decrease the risk of heart attack, stroke, or other cardiovascular events, except among women in their seventies. There were no significant differences in death rates or other outcomes between women taking 81 mg of aspirin compared to those taking 325 mg.
The size of the WHI Observational Study and the diversity of participants provide valuable insight into the use of medications in the primary care setting. For example, the study found that only 46 percent of women with stable cardiovascular disease in the study reported taking aspirin regularly, despite current guidelines recommendations. In addition, subgroup analyses indicate that black women and women with Medicaid insurance were less likely to use aspirin as recommended, compared to women of other ethnic groups and insurance status.
The WHI is a major, 15-year research program designed to address the most frequent causes of death, disability, and poor quality of life in postmenopausal women: cardiovascular disease, cancer, and osteoporosis. The WHI Observational Study is a nationwide, prospective study to examine the association between clinical, socioeconomic, behavioral, and dietary risk factors and the subsequent incidence of several health outcomes. The Observational Study followed 93,676 postmenopausal women between the ages of 50 and 79 for an average of 8 years. Participants filled out health forms and visited their clinic physician periodically; participants were not required to take any medication or change their health habits.
Broccoli may help protect against respiratory conditions like asthma
Here's another reason to eat your broccoli: UCLA researchers report that a naturally occurring compound found in broccoli and other cruciferous vegetables may help protect against respiratory inflammation that causes conditions like asthma, allergic rhinitis and chronic obstructive pulmonary disease.
Published in the March edition of the journal Clinical Immunology, the research shows that sulforaphane, a chemical in broccoli, triggers an increase of antioxidant enzymes in the human airway that offers protection against the onslaught of free radicals that we breathe in every day in polluted air, pollen, diesel exhaust and tobacco smoke. A supercharged form of oxygen, free radicals can cause oxidative tissue damage, which leads to inflammation and respiratory conditions like asthma.
"This is one of the first studies showing that broccoli sprouts — a readily available food source — offered potent biologic effects in stimulating an antioxidant response in humans," said Dr. Marc Riedl, the study's principal investigator and an assistant professor of clinical immunology and allergy at the David Geffen School of Medicine at UCLA.
"We found a two- to three-fold increase in antioxidant enzymes in the nasal airway cells of study participants who had eaten a preparation of broccoli sprouts," Riedl said. "This strategy may offer protection against inflammatory processes and could lead to potential treatments for a variety of respiratory conditions."
The UCLA team worked with 65 volunteers who were given varying oral doses of either broccoli or alfalfa sprout preparations for three days. Broccoli sprouts are the richest natural source of sulforaphane; the alfalfa sprouts, which do not contain the compound, served as a placebo.
Rinses of nasal passages were collected at the beginning and end of the study to assess the gene expression of antioxidant enzymes in cells of the upper airways. Researchers found significant increases of antioxidant enzymes at broccoli sprout doses of 100 grams and higher, compared with the placebo group.
The maximum broccoli sprout dosage of 200 grams generated a 101-percent increase of an antioxidant enzyme called GSTP1 and a 199-percent increase of another key enzyme called NQO1.
"A major advantage of sulforaphane is that it appears to increase a broad array of antioxidant enzymes, which may help the compound's effectiveness in blocking the harmful effects of air pollution," Riedl said.
According to the authors, no serious side effects occurred in study participants receiving broccoli sprouts, demonstrating that this may be an effective, safe antioxidant strategy to help reduce the inflammatory impact of free radicals.
Riedl notes that more research needs to be done to examine the benefits of sulforaphane for specific respiratory conditions. It is too early to recommend a particular dosage.
Riedl recommends including broccoli and other cruciferous vegetables as part of a healthy diet.
Vegetable-based drug could inhibit melanoma
Compounds extracted from green vegetables such as broccoli and cabbage could be a potent drug against melanoma, according to cancer researchers. Tests on mice suggest that these compounds, when combined with selenium, target tumors more safely and effectively than conventional therapy.
"There are currently no drugs to target the proteins that trigger melanoma," said Gavin Robertson, associate professor of pharmacology, pathology and dermatology, Penn State College of Medicine. "We have developed drugs from naturally occurring compounds that can inhibit the growth of tumors in mice by 50 to 60 percent with a very low dose."
Robertson and his colleagues previously showed the therapeutic potential of targeting the Akt3 protein in inhibiting the development of melanoma. The search for a drug to block the protein led them to a class of compounds called isothiocyanates.
These naturally occurring chemicals found in cruciferous vegetables are known to have certain cancer-fighting properties. However, the potency of these compounds is so low that a successful drug would require large impractical amounts of these compounds.
Instead, the Penn State researchers rewired the compounds by replacing their sulfur bonds with selenium. The result, they believe, is a more potent drug that can be delivered intravenously in low doses.
"Selenium deficiency is common in cancer patients, including those diagnosed with metastatic melanoma," explained Robertson, whose findings appear in the March edition of Clinical Cancer Research. "Besides, selenium is known to destabilize Akt proteins in prostate cancer cells."
To study the effectiveness of the new drug -- isoselenocyanate -- researchers injected mice with 10 million cancer cells. Six days later, when the animals developed large tumors, they were divided into two groups and treated separately with either the vegetable compounds or the compounds supplemented with selenium.
"We found that the selenium-enhanced compounds significantly reduced the production of Akt3 protein and shut down its signaling network," explained Robertson, who is also associate director of translational research and leader of the experimental therapeutics program at Penn State Hershey Cancer Institute. The modified compounds also reduced the growth of tumors by 60 percent, compared to the vegetable-based compounds alone.
When the researchers exposed three different human melanoma cell lines to the two compounds, the selenium-enhanced drug worked better on some cell lines than others. The efficiency was from 30 to 70 percent depending on the cell line.
The exact mechanism of how selenium inhibits cancer remains unclear. However Robertson, who has a filed provisional patent on the discovery, is convinced that the use of naturally occurring compounds that target cancer-causing proteins could lead to more effective ways of treating melanoma.
"We have harnessed something found in nature to target melanoma," said Robertson. "And since we only need tiny amounts to kill the cancer cells, it means even less toxic side-effects for the patient."
Human trials of the new drug are still some years away, but the Penn State researcher envisions a drug that could be delivered either intravenously to treat melanoma, or added to sunscreen lotion to prevent the disease.
The impact of a high-fat diet on the spread of cancer
Researchers at Purdue University have precisely measured the impact of a high-fat diet on the spread of cancer, finding that excessive dietary fat caused a 300 percent increase in metastasizing tumor cells in laboratory animals.
The researchers used an imaging technique to document how increasing fat content causes cancer cells to undergo changes essential to metastasis. Then they used another technique to count the number of cancer cells in the bloodstream of mice fed a high-fat diet compared to animals fed a lean diet.
The findings suggest that the combined tools represent a possible new diagnostic technique to determine whether a patient's cancer is spreading, said Ji-Xin Cheng, an assistant professor in Purdue's Weldon School of Biomedical Engineering and Department of Chemistry.
"It is generally accepted that diet and obesity are accountable for 30 percent of preventable causes of cancer, but nobody really knows why," Cheng said. "These findings demonstrate that an increase in lipids leads directly to a rise in cancer metastasis."
Researchers have theorized that tumor cells need more lipids than ordinary tissues to provide energy and material for tumor growth and metastasis.
"Before this work, however, most of the evidence was anecdotal, but here we present a mechanistic study," said Thuc T. Le, a National Institutes of Health postdoctoral fellow at Purdue who is working with Cheng.
Findings were detailed in a paper published on Jan. 30 in the journal BMC Cancer. The paper was written by Le; Terry B. Huff, a graduate research assistant in Purdue's Department of Chemistry; and Cheng. The research is supported by the Purdue Cancer Center.
The researchers implanted a cancerous lung tumor under the skin in each of the mice studied, and the animals were separated into two groups: one fed a high-fat diet and the other a lean diet.
The researchers then used an imaging method called coherent anti-Stokes Raman scattering, or CARS, to document how increasing lipids from fat intake induces changes to cancer cell membranes. Those changes, including processes called membrane phase separation and membrane rounding, enhance cancer metastasis.
"If the cancer cells don't have excess lipids they stick together and form very tight junctions in tumors, but increasing lipids causes them to take on a rounded shape and separate from each other," Le said.
The change in shape is critical to the ability of cancer cells to separate and spread throughout the body via the bloodstream.
The researchers then used another technique, called intravital flow cytometry, to count the number of cancer cells in the bloodstream of the mice. The technique works by shining a laser though the skin and into blood vessels, where the dyed cancer cells are visible.
Results showed the increase in lipids had no impact on the original tumors implanted in the mice. However, the rate of metastasis rose a dramatic 300 percent in the mice fed a high-fat diet.
The researchers later also examined the animals' lungs and counted the number of cancer cells that had migrated to the lungs as a result of metastasis. Those findings supported the other results showing increased metastasis in animals fed a high-fat diet.
The researches used the imaging and cell-counting tools to document that linoleic acid, which is predominant in polyunsaturated fats, caused increasing membrane phase separation, whereas oleic acid, found in monounsaturated fats, did not. Increased membrane phase separation could improve the opportunity of circulating tumor cells to adhere to blood vessel walls and escape to organs far from the original tumor site. The new findings support earlier evidence from other research that consuming high amounts of polyunsaturated fat may increase the risk of cancer spreading.
The findings suggest that combining CARS and intravital flow cytometry represents a possible new diagnostic tool to screen patients for cancer. The tool can be used to count lipid-rich tumor cells circulating in a patient's blood by shining a laser through the skin and into blood vessels. Because lipids can be detected without the need for dyes, the technique might be developed into a convenient method to diagnose whether a patient's cancer is spreading aggressively, Cheng said.
"These findings open the possibility of an entirely new, relatively simple method for diagnosing whether cancer is metastasizing," he said.
Future work will focus on not only how obesity increases metastasis but also how it might play a direct role in initiating the development of cancers.
Data Suggests a Diet High in Vegetable Intake Can Reduce Risk of Prostate Cancer
In the online edition of Molecular Nutrition and Food Research, Ruth Chan and collaborators provided a review on prostate cancer (CaP) and vegetable consumption. There is data that suggests a diet high in vegetable intake can reduce the risk of CaP. The primary mechanism of this protective vegetable effect is antioxidant protection against DNA and cell damage.
Available literature was identified for this review. Of the available studies, 29 were cohort studies, 69 case-control studies, and 4 randomized clinical trials. Highlights of this extensive review are presented herein. Tomatoes and their byproducts contain the carotenoid antioxidant lycopene. Two cohort studies reported tomatoes decreased CaP risk and 3 cohort studies reported a non-significant association. For case-control studies, 2 showed significant decreased risk and 5 showed a non-significant association. One study suggested that the potential benefit was greater in advanced as compared to localized CaP. Overall, studies for tomatoes and lycopenes show inconsistent results on decreasing CaP risk, but lycopene based foods are probably protective.
Yellow orange vegetables contain the antioxidant _-carotene. Data on _-carotene and CaP risk from cohort and case-control studies were inconclusive for a protective effect. Supplemental use of _-carotene was not shown to be protective. Flavonoids are a carbon structure compound ubiquitously present in plant foods and have anti-oxidative and anti-inflammatory properties. They may suppress angiogenesis, induction of apoptosis and down-regulation of hormone receptors expression. Overall there is some evidence suggesting that consumption of legumes, including soy and soy products, is protective against CaP.
Regarding vitamins, vitamin C has had limited study, but with the data available there is no evidence of a protective effect. Vitamin E is a naturally occurring fat-soluble vitamin found predominantly in plant foods and some animal foods. In a supplementation trial, there was suggestion that vitamin E was of benefit, but all the participants were smokers. Two other publications failed to show a benefit, and a preliminary report from the selenium and vitamin E trial does not suggest a benefit. As for allium vegetables which include garlic, onions, leeks, chives, scallions and shallots, while in vitro data suggest a protective benefit, population based studies are limited and a protective effect remains to be determined. Finally, cruciferous vegetables include broccoli, cauliflower Brussels sprouts, cabbage, bok choy, collard greens and kale. These are rich in sulforaphane and indole-3 carbinol, which have anticarcinogenic properties. To date, population-based studies are limited and a positive protective benefit remains to be determined.
Building Strong Bones: Running May Provide More Benefits Than Resistance Training, MU Study Finds
Osteoporosis affects more than 200 million people worldwide and is a serious public health concern, according to the National Osteoporosis Foundation. Resistance training often is recommended to increase and prevent loss of bone mineral density (BMD), although previous studies that examined the effects of resistance training in men produced varied results. Now, in a new study, University of Missouri researchers have found that high-impact activities, such as running, might have a greater positive effect on BMD than resistance training.
“The results of the study confirm that both resistance training and high-impact endurance activities increase bone mineral density. However, high-impact sports, like running, appear to have a greater beneficial effect,” said Pam Hinton, associate professor in the Department of Nutrition and Exercise Physiology in the MU College of Human Environmental Sciences.
According to the researchers, the true effects of weight-bearing or resistance exercise are only apparent when controlling for differences in body weight or composition. People who primarily perform non weight-bearing activities will benefit from resistance training that increases lean body mass, Hinton said. People who engage in activities, such as cycling, swimming, or rowing, should add bone-strengthening activities, such as resistance training or running, to their exercise regimens.
“Exercise programs to increase bone strength should be designed using what is known about how bones respond to exercise,” Hinton said. “Only the skeletal sites that experience increased stress from exercise will become stronger. For example, performing upper body resistance exercises will not increase bone mineral density of the hips. The response of bone to loading is determined by the magnitude of the force, and the rate and direction(s) at which it is applied. Therefore, high-impact, dynamic, multi-directional activities, including structured jump-training (plyometrics), result in greater gains in bone strength. Playing basketball, volleyball, or soccer are also good options.”
In the study, the researchers determined the effects of long-term running, cycling, and resistance training on whole-body and regional BMD, taking into account the effects of body weight and composition, in men ages 19 to 45. After adjusting for differences in lean body mass, the researchers found that runners had greater spine BMD than cyclists. Lean body mass was positively associated with BMD in both resistance-trained individuals and cyclists but not in runners; therefore, high-impact activity may override the benefits of lean body mass on BMD, Hinton said.
The study, “Lean body mass and weight-bearing activity in the prediction of bone mineral density in physically active men,” was published in the February issue of the Journal of Strength Conditioning.
New study shows how spikes in nitrite can have
(BOSTON) - A new study provides insight into how a short burst in nitrite can exert lasting beneficial effects on the heart, protecting it from stress and assaults such as heart attacks. In this study, just published in Circulation Research, researchers at Boston University School of Medicine have demonstrated for the first time that short elevations in circulating levels of this simple anion are sufficient to have a lasting impact on the heart by modulating its oxidation status and its protein machinery.
Nitrite, an oxidation product of the ubiquitous short-lived cell signaling molecule, nitric oxide (NO), was until recently thought to be biologically inert at the relatively low levels found in the body. Traces of nitrite are present in our diet and significant amounts are continuously produced from nitrate, another oxidation product of NO and a constituent of green, leafy vegetables. The suspicion that high levels of nitrite and nitrate may cause cancer, as well as concerns about their risk to compromise the ability of red blood cells to deliver oxygen to tissues, have led to strict regulations aimed at limiting our exposure to these substances through drinking water and food products.
In the past few years, however, multiple research groups have shown that low concentrations of nitrite exert numerous beneficial effects, ranging from anti-bacterial activities to increases in local blood flow, and that they can somehow protect tissues from damage when oxygen is suddenly cut off and then rapidly restored, as occurs during heart attacks and strokes.
To study the molecular underpinnings of this protective effect of nitrite, the researchers at Boston University School of Medicine used a rat model in which they administered nitrite only once, causing a short spike in circulating levels, as a way to simulate the types of naturally occurring increases in nitrite that follow exercise or consumption of a meal rich in nitrate.
The researchers used a systems-biology approach in which changes in multiple biological and biochemical systems (e.g., the composition of a large number of proteins, the concentration of several small molecule metabolites, and functional outcomes) are simultaneously monitored and then integrated to produce one final picture in order to provide a broader view of the impact of this treatment on the heart. They tested their theory that following these changes over time and at different doses of nitrite might help to explain the protective effects of nitrite on the heart.
"What we found was that a single brief nitrite treatment elicited persisting changes in the heart's oxidation status together with lasting alterations to numerous proteins involved in the heart's energy metabolism, redox regulation, and signaling," said David H. Perlman, a post-doctoral research associate in the Cardiovascular Proteomics Center at Boston University School of Medicine, and lead author of the study. "These alterations were particularly striking because they persisted at least 24 hours after the actual nitrite levels had returned back to normal, and they were correlated strongly with the improvements in heart function observed at the same time."
He noted that this type of protection, called 'cardiac preconditioning', is a recently discovered phenomenon shown to be caused by numerous pharmacological agents.
"The proteins we have implicated include some key proteins, such as mitochondrial aldehyde dehydrogenase, that have been shown by others to be critical to cardiac protection afforded by other agents and triggers," added Perlman. "This is exciting because it ties nitrite-triggered cardioprotection into the broader preconditioning field. Our study complements and extends other work, and identifies new players of potential importance for protection of the heart."
Perlman explained that nitrite levels in our bodies change under a number of circumstances, such as when we run up a flight of stairs or eat a big serving of salad.
"For years, the resulting bursts in nitrite were considered to be of little if any physiological relevance. Now we have good reason to believe that even small spikes in nitrite concentration can alter protein function in the heart in ways that afford protection," noted Perlman.
"We are intrigued by the breadth and magnitude of the proteomic changes in heart mitochondria elicited by a single, short-lasting elevation in nitrite concentration and believe that our findings will have broad implications for mitochondrial signalling and cardiac energetics," commented Martin Feelisch, senior author of the study. "It looks as though nitrite is triggering an ancient program aimed at fine-tuning mitochondrial function. Although the present study focussed on the heart, our observations may extend to other tissues and translate into relevant changes in muscle function elsewhere. If true, this may help explain, for example, the training effects of very short periods of exercise, which are known to be associated with elevations in circulating nitrite concentrations."
Interestingly, only low and high doses of nitrite, but not those in-between, were found to be protective. Although further studies will be needed to fully delineate the mechanisms of nitrite-induced cardioprotection, this study informs ongoing basic and translational studies by highlighting the importance of the dose-effect relationship for nitrite and the broad array of downstream targets possibly involved in its cardioprotective efficacy, the researchers concluded.
Health campaigns that promote exercise may cause people to eat more
New research from the University of Illinois suggests that campaigns that promote exercise may actually cause people to eat more.
People who viewed posters suggesting that they "join a gym" or "take a walk" ate more food after looking at the posters than people who saw similarly designed posters prompting them to "make friends" or "be in a group," the researchers found.
Subliminal words about being active had a similar effect on study participants, said psychology professor Dolores Albarracín, who led the research.
"Viewers of the exercise messages ate significantly more (than their peers, who viewed other types of messages)," she said. "They ate one-third more when exposed to the exercise ads." Those exposed to subliminal words about activity during a computer task ate about 20 percent more than those exposed to neutral words, she said.
The study, which appears in the journal Obesity, builds on previous research by Albarracín that suggests that general messages to be active can prompt people to behave in a variety of ways, some of which may have negative consequences.
Those designing public health campaigns are in the habit of trying to change one behavior at a time, Albarracín said. They should be aware that "whatever they communicate is likely to influence not only the behavior they had in mind but other behaviors that might be somewhat remotely linked," she said.
Teenage boys who eat fish at least once a week achieve higher intelligence scores
Fifteen-year-old males who ate fish at least once a week displayed higher cognitive skills at the age of 18 than those who it ate it less frequently, according to a study of nearly 4,000 teenagers published in the March issue of Acta Paediatrica.
Eating fish once a week was enough to increase combined, verbal and visuospatial intelligence scores by an average of six per cent, while eating fish more than once a week increased them by just under 11 per cent.
Swedish researchers compared the responses of 3,972 males who took part in the survey with the cognitive scores recorded in their Swedish Military Conscription records three years later.
"We found a clear link between frequent fish consumption and higher scores when the teenagers ate fish at least once a week" says Professor Kjell Torén from the Sahlgrenska Academy at the University of Gothenburg, one of the senior scientists involved in the study. "When they ate fish more than once a week the improvement almost doubled.
"These findings are significant because the study was carried out between the ages of 15 and 18 when educational achievements can help to shape the rest of a young man's life."
The research team found that:
0. 58 per cent of the boys who took part in the study ate fish at least once a week and a further 20 per cent ate fish more than once a week.
0.
0. When male teenagers ate fish more than once a week their combined intelligence scores were on average 12 per cent higher than those who ate fish less than once a week. Teenagers who ate fish once a week scored seven per cent higher.
0.
0. The verbal intelligence scores for teenagers who ate fish more than once a week were on average nine per cent higher than those who ate fish less than once a week. Those who ate fish once a week scored four per cent higher.
0.
0. The same pattern was seen in the visuospatial intelligence scores, with teenagers who ate fish more than once a week scoring on average 11 per cent higher than those who ate fish less than once a week. Those who ate fish once a week scored seven per cent higher.
0.
"A number of studies have already shown that fish can help neurodevelopment in infants, reduce the risk of impaired cognitive function from middle age onwards and benefit babies born to women who ate fish during pregnancy" says Professor Torén.
"However we believe that this is the first large-scale study to explore the effect on adolescents."
The exact mechanism that links fish consumption to improved cognitive performance is still not clear.
"The most widely held theory is that it is the long-chain polyunsaturated fatty acids found in fish that have positive effects on cognitive performance" explains Professor Torén.
"Fish contains both omega-3 and omega-6 fatty acids which are known to accumulate in the brain when the foetus is developing. Other theories have been put forward that highlight their vascular and anti-inflammatory properties and their role in suppressing cytokines, chemicals that can affect the immune system."
In order to isolate the effect of fish consumption on the study subjects, the research team looked at a wide range of variables, including ethnicity, where they lived, their parents' educational level, the teenagers' well-being, how frequently they exercised and their weight.
"Having looked very carefully at the wide range of variables explored by this study it was very clear that there was a significant association between regular fish consumption at 15 and improved cognitive performance at 18" concludes lead author Dr Maria Aberg from the Centre for Brain Repair and Rehabilitation at the University of Gothenburg.
"We also found the same association between fish and intelligence in the teenagers regardless of their parents' level of education."
The researchers are now keen to carry out further research to see if the kind of fish consumed - for example lean fish in fish fingers or fatty fish such as salmon - makes any difference to the results.
"But for the time being it appears that including fish in a diet can make a valuable contribution to cognitive performance in male teenagers" says Dr Aberg.
Go green for healthy teeth and gums
Recent study suggests that antioxidants in green tea may help reduce periodontal disease
With origins dating back over 4,000 years, green tea has long been a popular beverage in Asian culture, and is increasingly gaining popularity in the United States. And while ancient Chinese and Japanese medicine believed green tea consumption could cure disease and heal wounds, recent scientific studies are beginning to establish the potential health benefits of drinking green tea, especially in weight loss, heart health, and cancer prevention. A study recently published in the Journal of Periodontology, the official publication of the American Academy of Periodontology (AAP), uncovered yet another benefit of green tea consumption. Researchers found that routine intake of green tea may also help promote healthy teeth and gums. The study analyzed the periodontal health of 940 men, and found that those who regularly drank green tea had superior periodontal health than subjects that consumed less green tea.
"It has been long speculated that green tea possesses a host of health benefits," said study author Dr. Yoshihiro Shimazaki of Kyushu University in Fukuoka, Japan. "And since many of us enjoy green tea on a regular basis, my colleagues and I were eager to investigate the impact of green tea consumption on periodontal health, especially considering the escalating emphasis on the connection between periodontal health and overall health."
Male participants aged 49 through 59 were examined on three indicators of periodontal disease: periodontal pocket depth (PD), clinical attachment loss (CAL) of gum tissue, and bleeding on probing (BOP) of the gum tissue. Researchers observed that for every one cup of green tea consumed per day, there was a decrease in all three indicators, therefore signifying a lower instance of periodontal disease in those subjects who regularly drank green tea.
Green tea's ability to help reduce symptoms of periodontal disease may be due to the presence of the antioxidant catechin. Previous research has demonstrated antioxidants' ability to reduce inflammation in the body, and the indicators of periodontal disease measured in this study, PD, CAL and BOP, suggest the existence of an inflammatory response to periodontal bacteria in the mouth. By interfering with the body's inflammatory response to periodontal bacteria, green tea may actually help promote periodontal health, and ward off further disease. Periodontal disease is a chronic inflammatory disease that affects the gums and bone supporting the teeth, and has been associated with the progression of other diseases such as cardiovascular disease and diabetes.
"Periodontists believe that maintaining healthy gums is absolutely critical to maintaining a healthy body," says Dr. David Cochran, DDS, PhD, President of the AAP and Chair of the Department of Periodontics at the University of Texas Health Science Center at San Antonio. "That is why it is so important to find simple ways to boost periodontal health, such as regularly drinking green tea – something already known to possess certain health-related benefits."
1 in 7 U.S. Teens Is Vitamin D Deficient
Weill Cornell Medical College Study Finds Prevalence Highest Among African-Americans
One in seven American adolescents is vitamin D deficient, according to a new study by researchers in the Department of Public Health at Weill Cornell Medical College. The findings are published in the March issue of the journal Pediatrics and were presented at the Pediatric Academic Societies' Annual Meeting in May 2008.
In children, vitamin D deficiency can interfere with bone mineralization, leading to rickets. In adults, it is linked to cardiovascular disease, cancer, diabetes, immune dysfunction and hypertension.
The study employs a new definition of vitamin D deficiency recommended by a group of scientists attending the 13th Workshop Consensus for Vitamin D Nutritional Guidelines in 2007. These experts collectively proposed that the minimum acceptable serum vitamin D level be raised from 11 nanograms per milliliter (ng/mL) to at least 20 ng/mL.
Using the newer criteria, the study finds more than half of African-American teens are vitamin D deficient. Girls had more than twice the risk of deficiency compared with boys. And overweight teens had nearly double the risk of their normal-weight counterparts.
"These are alarming findings. We need to do a better job of educating the public on the importance of vitamin D, and the best ways to get it. To meet minimum nutritional requirements teens would need to consume at least four glasses of fortified milk daily or its dietary equivalent. Other foods rich in vitamin D include salmon, tuna, eggs and fortified cereals. A vitamin supplement containing 400 IU of vitamin D is another alternative," says Dr. Sandy Saintonge, assistant professor of clinical pediatrics and assistant professor of clinical public health at Weill Cornell Medical College, and a pediatric emergency physician at New York Hospital Queens, a member of the NewYork-Presbyterian Hospital Healthcare System. "We should also consider a national fortification strategy, perhaps including routine supplementation and monitoring of serum levels, but more research is needed to determine optimal vitamin D levels."
Of the specific findings, the authors were particularly concerned about the role of weight in deficiency. "Because vitamin D is stored in body fat, simply increasing the dosage of vitamin D may not be effective in overweight adolescents," notes senior author Dr. Linda M. Gerber, professor of public health in the Division of Biostatistics and Epidemiology and professor of epidemiology in medicine at Weill Cornell Medical College. "As the prevalence of childhood obesity increases, vitamin D deficiency may increase as well. In this group, appropriate nutrition could solve both problems."
Another concern is the increased risk of deficiency in girls, some of whom may become pregnant during adolescence. The authors note that a lack of vitamin D may increase maternal risk of preeclampsia and gestational diabetes and may be associated with reduced bone mineralization in the offspring.
Data was obtained from National Health and Nutrition Examination Survey III, a cross-sectional survey administered to a nationally representative sample of persons aged 2 months and older. Analyses were restricted to 2,955 participants aged 12 to 19.
Low vitamin D levels associated with several risk factors in teenagers
Study highlights:
• Low levels of vitamin D were associated with increased risk of high blood pressure, high blood sugar and metabolic syndrome in teenagers.
• The highest levels of vitamin D were found in whites, the lowest levels in blacks and intermediate levels in Mexican-Americans.
Low levels of vitamin D were associated with an increased risk of high blood pressure, high blood sugar and metabolic syndrome in teenagers, researchers reported at the American Heart Association’s 49th Annual Conference on Cardiovascular Disease Epidemiology and Prevention.
In the study, researchers analyzed 3,577 adolescents, 12 to 19 years old (51 percent boys), who participated in the nationally representative National Health and Nutrition Examination Survey (NHANES) conducted from 2001–2004.
After adjusting for age, sex, race/ethnicity, body mass index, socioeconomic status and physical activity, researchers found the adolescents with the lowest levels of vitamin D were:
• 2.36 times more likely to have high blood pressure;
• 2.54 times more likely to have high blood sugar; and
• 3.99 times more likely to have metabolic syndrome.
Metabolic syndrome is a cluster of cardiovascular disease and diabetes risk factors including elevated waist circumference, high blood pressure, elevated triglycerides, low levels of high-density lipoprotein (HDL or “good”) cholesterol and high fasting glucose levels. The presence of three or more of the factors increases a person’s risk of developing diabetes and cardiovascular disease.
“We showed strong associations between low levels of vitamin D and higher risk of high blood pressure, hyperglycemia and metabolic syndrome among adolescents, confirming the results of studies among adults,” said Jared P. Reis, Ph.D., the study’s lead author and post-doctoral research fellow at Johns Hopkins Bloomberg School of Public Health in Baltimore.
Researchers used a biomarker of vitamin D to measure levels in blood. The biomarker measures vitamin D obtained from food, vitamin supplementation and exposure to sunlight.
The ethnic breakdown was similar to the general U.S. population: 64.7 percent non-Hispanic whites; 13.5 percent non-Hispanic blacks; and 11 percent Mexican Americans.
The study highlights the association between high levels of vitamin D and lower risk of heart disease. The highest levels of vitamin D were found in whites, the lowest levels in blacks and intermediate levels in Mexican Americans. Whites had almost twice as high levels as blacks.
In whites, the average level of vitamin D was 28.0 nanograms per milliliter (ng/mL); in blacks, 15.5 ng/mL; and in Mexican Americans, 21.5 ng/mL.
“Although our study is important, we believe clinical trials designed to determine the effects of vitamin D supplementation on the risk of heart disease risk factors in adolescents should be conducted before recommendations can be made for vitamin D in the prevention of cardiovascular disease,” Reis said.
The Institute of Medicine recommends a daily intake of vitamin D of 200 International Units (IU) for those less than 50 years, which includes children and adolescents. More recent recommendations, however, from the American Academy of Pediatrics suggests a daily intake of 400 IU daily. While these intakes have been shown to be important in the prevention of skeletal conditions such as rickets in children and osteoporosis in adults, some specialists have suggested intakes of at least 1,000 IU daily may be needed for overall health.
Low levels of vitamin D are strongly associated with overweight and abdominal obesity. Since vitamin D is a fat-soluble vitamin, it may be sequestered within adipose tissue. This may explain why those who are obese are more likely to be vitamin D deficient, Reis said.
Vitamin D plays a useful role in general human health, particularly in bone health. Other roles are emerging, Reis said. “This is an exciting time; since we are just now beginning to understand the role that vitamin D may play in cardiovascular health.”
“These data on serum vitamin D levels in young people raise some concern about their food choices and even the amount of time they spend in the sunshine,” said Robert H. Eckel, M.D., American Heart Association past president. “The American Heart Association recommends an overall healthy diet and lifestyle, and that people get their nutrients primarily from food sources rather than supplements.”
Not enough vitamin D in the diet could mean too much fat on adolescents
Too little vitamin D could be bad for more than your bones; it may also lead to fatter adolescents, researchers say.
A Medical College of Georgia study of more than 650 teens age 14-19 has found that those who reported higher vitamin D intakes had lower overall body fat and lower amounts of the fat in the abdomen, a type of fat known as visceral fat, which has been associated with health risks such as heart disease, stroke, diabetes and hypertension.
The group with the lowest vitamin D intake, black females, had higher percentages of both body fat and visceral fat, while black males had the lowest percentages of body and visceral fat, even though their vitamin D intake was below the recommended levels. Only one group – white males – was getting the recommended minimum intake of vitamin D.
“This study was a cross-section so, while it cannot prove that higher intake of vitamin D caused the lower body fat, we know there is a relationship that needs to be explored further," says Dr. Yanbin Dong, a molecular geneticist and cardiologist at the MCG Gerogia Prevention Institute.
Dr. Dong, who also co-directs the MCG Diabetes & Obesity Discovery Institute, and Inger Stallman-Jorgensen, a research dietician at the GPI, present their findings this week at the American Heart Association’s Joint 49th Conference on Cardiovascular Disease Epidemiology and Prevention and Nutrition, Physical Activity and Metabolism in Palm Harbor, Fla.
The pair will next study whether it is feasible for teens to take a daily vitamin D supplement in pill form. Those results will help them design a larger study to explore the relationship between vitamin D intake and body fat levels in teens.
“We already know that encouraging teens to get an adequate amount of vitamin D in their diets will help promote a healthy body as they grow and develop,” Ms. Stallman-Jorgensen says. “Now we need to do intervention studies where we give teens vitamin D supplements to determine if there is a cause and effect relationship between vitamin D intake and fat.”
The American Academy of Pediatrics recommends adolescents get at least 400 units of vitamin D per day – either from milk or sun exposure. There are typically 100 units in one 8-ounce glass of whole milk. The recommended daily dose from the sun would require at least 30 minutes of adequate exposure to direct sunlight two or three times a week at peak hours, between noon and 3 p.m.
Ms. Stallman-Jorgensen said there are many reasons teens don't get enough vitamin D, which has been linked to the prevention of diabetes, cancer and cardiovascular disease.
“As humans, our largest source of vitamin D should be the sun. But we don’t spend enough time outdoors to get enough sun exposure and when we do, we’re often covered up and wearing sunscreen," she said. "We can get vitamin D from certain foods, like fatty fish and liver, but it’s not in a lot of foods that we commonly consume. In this country, our milk is fortified with vitamin D. Unfortunately, teens just don’t drink enough milk to get their daily requirements.”
She points out that low sunlight during the winter months reduces the amount of vitamin D the skin produces, and that darker-skinned people obtain less vitamin D from the sun because the extra melanin in their skin filters out more sunlight.
Some people can't tolerate milk because they lack the enzyme that processes lactose, the natural sugar in milk, though "most people can handle it in small amounts,” Ms. Stallman says.
Cultural issues may also be at play, Ms. Stallman-Jorgensen says.
“Most teens want to drink sodas and sugary drinks. It’s not cool to drink milk – they think of it as more of a food for babies,” she said.
Potential study participants had their weekday and weekend diets tracked by researchers seven times during a three-month period. Those who provided at least four diet reports were included in the final group of 659.
Body fat percentages were measured by dual energy X-ray absorptiometry scans, which can measure total body composition. Visceral fat was measured in a subset of 432 teens.
Long-Term Use Of Nutrient Supplements May Increase Cancer Risk
Long-term use of beta carotene and some other carotenoid-containing dietary supplements may increase the risk of lung cancer, especially among smokers, according to a study by University of North Carolina at Chapel Hill researchers. The study, which also examined use of retinol, vitamin A, lycopene and lutein, appears in the February issue of the American Journal of Epidemiology.
Researchers used questionnaires to assess use of dietary supplements, including multi-vitamins and individual nutrients, by more than 77,000 Americans over 10 years, and matched the results against data from the Surveillance, Epidemiology and End Results (SEER) cancer registry to track the rates of lung cancer among them.
They found that certain people – especially smokers – who took dietary supplements containing these nutrients, were at higher risk of developing lung cancer than the general population.
“In the 1980s, studies began showing the link between diet and cancers, and showing that eating fruits and vegetables could lower your risk of certain cancers, including lung cancer,” said Jessie Satia, Ph.D., associate professor of epidemiology and nutrition at the UNC Gillings School of Global Public Health and member of UNC’s Lineberger Comprehensive Cancer Center. “Scientists wondered, then, if you took the beneficial nutrients from fruits and vegetables and gave high doses of them to persons at high risk for lung cancer, such as smokers, if you could decrease the risk of lung cancer.”
However, subsequent clinical trials proved that high doses of beta carotene actually seemed to increase the risk of developing lung cancer, Satia said, and trials in the United States and Sweden were stopped when the increased risk was detected.
“But that was in clinical trials, under controlled circumstances,” Satia said. “We wanted to see if the same results would be found if we looked at use of these supplements in the general population.”
Satia and colleagues from UNC and the University of Washington in Seattle gave questionnaires to men and women, aged 50 to 76, in western Washington state. Participants were asked about their use of multivitamins and individual nutrient supplements over the past 10 years (including frequency and dose), as well as about their health history and risk factors. Participants were followed for the next four years, at which time lung cancer rates were obtained.
The results show that smokers’ risk of developing lung cancer increased with the length of time they took dietary supplements containing beta carotene, retinol and lutein.
“The risk increased the longer the person had taken the supplements,” Satia said. “The amount of time the person took supplements seemed to have a greater effect than the dose. Even a modest dose, if taken for a long time, can increase the risks of lung cancer, especially among smokers.”
For example, the study found that use of retinol and lutein supplements for four years or longer was associated with increases in lung cancer risk of 53 percent and 102 percent, respectively.
The risk for nonsmokers could not be determined because lung cancer cases among nonsmokers was small, Satia said.
“We believe beta-carotene is an antioxidant, but it seems that if you take too much, at some point it can have pro-oxidant effects, which can result in elevated cancer risk.”
Vitamin C intake associated with lower risk of gout in men
Men with higher vitamin C intake appear less likely to develop gout, a painful type of arthritis, according to a report in the March 9 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
"Gout is the most common type of inflammatory arthritis in men," the authors write as background information in the article. "Epidemiologic studies suggest that the overall disease burden of gout is substantial and growing. The identification of the risk factors for gout that are modifiable with available measures is an important first step in the prevention and management of this common and excruciatingly painful condition."
Hyon K. Choi, M.D., Dr.P.H., then of University of British Columbia, Vancouver, and now of Boston University School of Medicine, and colleagues examined the relationship between vitamin C intake and gout in 46,994 men between 1986 and 2006. Every four years, the men completed a dietary questionnaire, and their vitamin C intake through food and supplements was computed. Every two years, participants reported whether they had been diagnosed with or developed symptoms of gout.
During 20 years of follow-up, 1,317 men developed gout. Compared with men who had a vitamin C intake of less than 250 milligrams per day, the relative risk of gout was 17 percent lower for those with a daily intake of 500 to 999 milligrams, 34 percent lower for those with an intake of 1,000 to 1,499 milligrams per day and 45 percent lower for those with an intake of 1,500 milligrams per day or higher. For every 500-milligram increase in their vitamin C intake, men's risk for gout appeared to decrease by 17 percent. Compared with men who did not take vitamin C supplements, those who took 1,000 to 1,499 supplemental milligrams per day had a 34 percent lower risk of gout and those who took 1,500 supplemental milligrams per day had a 45 percent lower risk.
Vitamin C appears to reduce levels of uric acid in the blood, the authors note; a buildup of this naturally occurring compound can form crystal deposits in and around joints, leading to the pain, inflammation and swelling associated with gout. Vitamin C may affect reabsorption of uric acid by the kidneys, increase the speed at which the kidneys work or protect against inflammation, all of which may reduce gout risk, the authors note.
"Given the general safety profile associated with vitamin C intake, particularly in the generally consumed ranges as in the present study (e.g., tolerable upper intake level of vitamin C of less than 2,000 milligrams in adults according to the Food and Nutrition Board, Institute of Medicine), vitamin C intake may provide a useful option in the prevention of gout," they conclude.
Drinking wine lowers risk of Barrett's esophagus, precursor to nation's fastest growing cancer
Kaiser Permanente study is first & largest to examine connection between alcohol & Barrett's esophagus
Drinking one glass of wine a day may lower the risk of Barrett's Esophagus by 56 percent, according to a new study by the Kaiser Permanente Division of Research in the March issue of Gastroenterology. Barrett's Esophagus is a precursor to esophageal cancer, the nation's fastest growing cancer with an incidence rate that's jumped 500 percent in the last 30 years.
Barrett's Esophagus affects 5 percent of the population and occurs when heartburn or acid reflux permanently damages the esophageal lining. People with Barrett's Esophagus have a 30- to 40-fold higher risk of developing esophageal adenocarcinoma (a type of esophageal cancer) because the Barrett's Esophagus cells can grow into cancer cells.
Because there are no symptoms or warning signs of Barrett's Esophagus, people discover they have Barrett's Esophagus when an endoscopy for anemia, heartburn or a bleeding ulcer reveals esophageal cells that were damaged, then changed form during the healing process. Currently nothing can be done to treat Barrett's Esophagus; it can only be monitored.
This is the first and largest population-based study to examine the connection between alcohol consumption and risk of Barrett's Esophagus. Funded in part by the National Institutes of Health, the Kaiser Permanente study looked at 953 men and women in Northern California between 2002 and 2005 and found that people who drank one or more glasses of red or white wine a day had less than half the risk (or 56 percent reduced risk) of Barrett's Esophagus. There was no reduction of Barrett's Esophagus risk among people who drank beer or liquor.
"The rate of esophageal adenocarcinoma in this country is skyrocketing yet very little is known about its precursor, Barrett's Esophagus. We are trying to figure out how to prevent changes that may lead to esophageal cancer." said Douglas A. Corley, MD, a Kaiser Permanente gastroenterologist and the study's principal investigator.
The study findings are echoed by two other studies published in the same issue of the Gastroenterology journal: Australian researchers found that people who drank wine were at a lower risk of esophageal adenocarcinoma, and Irish researchers found that people who drank wine were at a lower risk for esophagitis, an irritation of the esophagus that follows chronic heartburn and often precedes Barrett's Esophagus and cancer.
Researchers are not certain why wine reduces the risk of Barrett's Esophagus and esophageal cancer. One theory is that the wine's antioxidants neutralize the oxidative damage caused by gastroesophageal reflux disease, a risk factor for Barrett's Esophagus. Another theory is that wine drinkers typically consume food with their wine as opposed to drinking straight liquor without food, thereby reducing the potentially damaging effect of alcohol on esophageal tissue, said Ai Kubo, MD, an epidemiologist at Kaiser Permanente and lead author on the study. "But we cannot preclude the possibility that wine drinking is a proxy for other 'health-seeking' behavior," Kubo added.
This study is part of larger, case-controlled Kaiser Permanente study led by Dr. Corley that looked at abdominal obesity and consumption of dietary antioxidants, fruits and vegetables in connection with Barrett's Esophagus. It found that people can reduce their risk of Barrett's Esophagus by eating eight servings of fruits and vegetables a day and maintaining a normal body weight.
"My advice to people trying to prevent Barrett's Esophagus is: keep a normal body weight and follow a diet high in antioxidants and high in fruits and vegetables," Corley said. "We already knew that red wine was good for the heart, so perhaps here is another added benefit of a healthy lifestyle and a single glass of wine a day."
Researchers noted, though, that the protective effect of wine in terms of preventing Barrett's Esophagus was greatest with just one or two glasses a day. The protective effect of wine did not increase with higher consumption.
"It's not actually clear that treating the acid reflux will necessarily prevent getting someone from getting Barrett's Esophagus," said Dr. Corley. "The best way to prevent reflux is to maintain a normal weight."
Moderate alcohol intake associated with bone protection
Epidemiological study examines effects of beer, wine and liquor on BMD
In an epidemiological study of men and post-menopausal women primarily over 60 years of age, regular moderate alcohol intake was associated with greater bone mineral density (BMD). Researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University found associations were strongest for beer and wine and, importantly, BMD was significantly lower in men drinking more than two servings of liquor per day. The results suggest that regular moderate consumption of beer or wine may have protective effects on bone, but that heavy drinking may contribute to bone loss.
"Previous research suggests that moderate alcohol consumption in older men and post-menopausal women may protect against BMD loss, a major risk factor for osteoporosis," said Katherine L. Tucker, PhD, corresponding author and director of the Dietary Assessment and Epidemiology Research Program at the USDA HNRCA. The 2005 Dietary Guidelines issued by the federal government defines moderate alcohol consumption as one drink per day for women and two drinks per day for men.
"Our study also looks at the possible effects of the three alcohol classes, beer, wine and liquor on BMD," Tucker continued. "We saw stronger associations between higher BMD and beer drinkers, who were mostly men, and wine drinkers, who were mostly women, compared to liquor drinkers." The results were published online February 25 by the American Journal of Clinical Nutrition.
Tucker, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts, and colleagues analyzed BMD measurements taken at three hip sites and the lumbar spine in 1,182 men, 1,289 post-menopausal women, and 248 pre-menopausal women whose parents or in-laws participated in the original Framingham Heart Study. There was not enough data to determine the effects of more than two servings of alcohol per day in post-menopausal women or the effects of daily alcohol consumption on BMD in pre-menopausal women. Participants self-reported their alcohol intake on dietary questionnaires. One serving of beer equaled a glass, bottle or can (356 mL), one serving of wine equaled a 4-oz. glass (118 mL), and one serving of liquor equaled one mixed drink or shot (42 mL).
After adjusting for several other factors that may have accounted for the higher BMD, such as silicon intake, calcium intake and smoking history, the authors still saw an association between higher BMD and moderate alcohol consumption. One of the strongest associations was seen in men who reported consuming one or two servings of total alcohol (a combination of beer, wine and liquor) or one or two servings of beer per day. Hip BMD in this group was significantly greater compared to non-drinkers.
In contrast, the authors observed significantly lower BMD at the hip and spine in men who consumed more than two servings of liquor per day compared to men who consumed one or two servings of liquor per day. "There is a body of research showing alcoholism is devastating to bones," Tucker said. "It's a major risk factor for osteoporosis. No one should depend solely on alcohol to maintain bone health."
The authors hypothesize that the silicon found in beer is contributing to the higher BMD scores in the men who reported consuming one or two servings of total alcohol or beer per day, citing previous studies finding silicon has greater bioavailability as a liquid. It is less clear why liquor and wine might protect BMD.
"We cannot say definitively what component of these alcoholic drinks might be beneficial to bone health because our findings are from an observational study, as opposed to a clinical trial," Tucker said. "Future studies might dig deeper into patterns of alcohol consumption, as we relied on a self-reported dietary questionnaire. Another component of data worthy of exploration is whether the antioxidants found in wine, such as revesterol or polyphenols, have a protective effect on bone in addition to other health benefits."
Georgetown researcher: 2 or more drinks a day may increase pancreatic cancer risk
Men and women who consume two or more alcoholic drinks a day could increase their risk of developing pancreatic cancer, according to a study published in Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research.
Previous studies have been unable to confirm the association between drinking and the risk of pancreatic cancer, but most studies depended on a person's recall of alcohol intake. Still, many hypothesize about the relationship between alcohol and pancreatic cancer because drinking is associated with the risk of pancreatitis and diabetes, and both of these conditions are known risk factors for developing the disease.
Unlike the previous studies, this current research pools data collected prospectively from 14 research studies, which included 862,664 individuals (319,716 men and 542,948 women). Data collected prospectively means information about dietary and environmental exposures were collected prior to diagnosis with pancreatic cancer. Researchers identified 2,187 individuals diagnosed with pancreatic cancer during the study.
"This is one of the largest studies ever to look at dietary factors in relation to pancreatic cancer risk," says lead author Jeanine M. Genkinger, Ph.D., an assistant professor at Georgetown University's Lombardi Comprehensive Cancer Center.
If individuals consumed 30 or more grams of alcohol per day (approximately two drinks), compared with no alcohol per day, their risk of pancreatic cancer was slightly increased, researchers said. A drink is defined as 12 ounces of beer, four ounces of wine, or 1.5 ounces of 80-proof distilled liquor.
Although, there was no statistically significant difference between men and women when comparing alcohol intake with risk of pancreatic cancer, the association was seen in women at two or more drinks per day. Comparatively, the researchers observed a higher risk among men who consumed three or more drinks a day.
No difference was observed by type of alcohol when comparing beer, distilled liquor or wine, according to Genkinger.
"Despite being a deadly disease, there are few known risk factors for developing pancreatic cancer," explains Genkinger. "At this point, it's important to understand any protective or risk factors for this dangerous disease even if the risks are weak or modest."
Red wine vs. white? It makes no difference when it comes to breast-cancer risk
The largest study of its kind to evaluate the effect of red versus white wine on breast-cancer risk concludes that both are equal offenders when it comes to increasing breast-cancer risk. The results of the study, led by researchers at Fred Hutchinson Cancer Research Center, were published in the March issue of Cancer Epidemiology, Biomarkers and Prevention.
"We were interested in teasing out red wine's effects on breast-cancer risk. There is reason to suspect that red wine might have beneficial effects based on previous studies of heart disease and prostate cancer," said lead author Polly Newcomb, Ph.D., M.P.H., head of the Cancer Prevention Program in the Public Health Sciences Division at the Hutchinson Center. "The general evidence is that alcohol consumption overall increases breast-cancer risk, but the other studies made us wonder whether red wine might in fact have some positive value."
Instead, Newcomb and colleagues found no compelling reason to choose Chianti over Chardonnay.
"We found no difference between red or white wine in relation to breast-cancer risk. Neither appears to have any benefits," Newcomb said. "If a woman drinks, she should do so in moderation – no more than one drink a day. And if a woman chooses red wine, she should do so because she likes the taste, not because she thinks it may reduce her risk of breast cancer," she said.
The researchers found that women who consumed 14 or more drinks per week, regardless of the type (wine, liquor or beer), faced a 24 percent increase in breast cancer compared with non-drinkers.
For the study, the researchers interviewed 6,327 women with breast cancer and 7,558 age-matched controls about their frequency of alcohol consumption (red wine, white wine, liquor and beer) and other breast-cancer risk factors, such as age at first pregnancy, family history of breast cancer and postmenopausal hormone use. The study participants, ages 20 to 69, were from Wisconsin, Massachusetts and New Hampshire. The frequency of alcohol consumption was similar in both groups, and equal proportions of women in both groups reported consuming red and white wine.
