Archive for April 2010

Low vitamin D levels are related to ms brain atrophy, cognitive function

Thursday, April 29, 2010

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Low vitamin D levels may be associated with more advanced physical disability and cognitive impairment in persons with multiple sclerosis, studies conducted by neurologists at the University at Buffalo have shown.

Their results, reported at the American Academy of Neurology meeting, held earlier this month, indicated that:

The majority of MS patients and healthy controls had insufficient vitamin D levels.
Clinical evaluation and magnetic resonance imaging (MRI) images show low blood levels of total vitamin D and certain active vitamin D byproducts are associated with increased disability, brain atrophy and brain lesion load in MS patients.
A potential association exists between cognitive impairment in MS patients and low vitamin D levels.
The MRI study involved 236 MS patients -- 208 diagnosed with the relapsing-remitting type and 28 with secondary progressive, a more destructive form of MS -- and 22 persons without MS.

All participants provided blood serum samples, which were analyzed for total vitamin D (D2 and D3) levels as well as levels of active vitamin D byproducts. MRI scans performed within three months of blood sampling were available for 163 of the MS patients.

Results showed that only seven percent of persons with secondary-progressive MS showed sufficient vitamin D, compared to 18.3 percent of patients with the less severe relapsing-remitting type.

Higher levels of vitamin D3 and vitamin D3 metabolism byproducts (analyzed as a ratio) also were associated with better scores on disability tests, results showed, and with less brain atrophy and fewer lesions on MRI scans.

Bianca Weinstock-Guttman, MD, UB associate professor of neurology/Jacobs Neurological Institute and director of the Baird Multiple Sclerosis Center, is first author on the study. Commenting on these results, Weinstock-Guttman said: "Clinical studies are necessary to assess vitamin D supplementation and the underlying mechanism that contributes to MS disease progression."

While lower-than-normal vitamin D status is known to be associated with a higher risk of developing MS, little is known about its relationship to cognitive impairment.

Sarah A. Morrow, MD, UB assistant research professor of neurology/Jacobs Neurological Institute and lead author on the cognitive-impairment study, compared vitamin D levels in blood samples of 136 MS patients with the results of their neuropsychological assessments that tested multiple types of cognition affected by MS.

"Results showed that MS patients who were impaired on tests of executive function --critical reasoning and abstract thinking -- and the ability to plan and organize, were more likely to be deficient in vitamin D," said Morrow.

"This relationship held true when controlling for the season during which vitamin D was measured, as well as depression, which is known to be associated with lower vitamin D levels." Morrow noted there also was a suggestion that verbal fluency (word generation) and visual-spatial memory (learning and memory of shapes and figures) is more likely to be affected when vitamin D levels are not sufficient.
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Peppers May Help Lose Weight

Imagine your delight while enjoying your favorite Mexican food -- perhaps a fully loaded bean burrito topped with an ample supply of thinly sliced jalepeño peppers. What happens when you bite into a few more peppers than you bargained for? Does this thought conjure up the thought of a little heat? Perhaps even a bit of sweat on the brow?

Indeed, food scientists can tell you that hot peppers contain a substance called capsaicin that not only adds spice to our foods but can actually cause your body to heat up. They hypothesize that plants evolved to contain capsaicin because it protected them from being eaten by insects and other pesky predators. On the contrary, cuisines worldwide rely on capsaicin-packing peppers to add pungency and zing to many traditional foods, and "pepperheads" often choose their meal to purposefully turn up the heat.

But scientists are learning there is more than meets the eye (or should we say taste buds) when it comes to peppers. In fact, there is growing evidence that the body-heat-generating power of peppers might even lend a hand in our quest to lose those extra inches accumulating around our collective national waistline. And fortunately for those of us who don't appreciate the "burn" of hot peppers, there are plants that make a non-burning version of capsaicin called dihydrocapsiate (DCT) that could have the benefits of peppers without the pungency.

In a study designed to test the weight-loss potential of this DCT containing, non-spicy cousin of hot peppers, researchers at the UCLA Center for Human Nutrition set out to document its ability to increase heat production in human subjects consuming a weight-loss diet. Under the direction of David Heber (Professor of Medicine and Public Health), they recruited 34 men and women who were willing to consume a very low-calorie liquid meal replacement product for 28 days. The researchers then randomized the subjects to take either placebo pills or supplements containing the non-burning DCT pepper analog. Two dosage levels of DCT were tested. At the beginning and end of the study, body weight and body fat were assessed, and the researchers determined energy expenditure (heat production) in each subject after he or she consumed one serving of the test meal.

On April 27, Heber and his research team presented their results at the Experimental Biology 2010 meeting in Anaheim, CA. This presentation is part of the scientific program of the American Society for Nutrition, home to the world's leading nutrition researchers.

Their data provided convincing evidence that, at least for several hours after the test meal was consumed, energy expenditure was significantly increased in the group consuming the highest amount of DCT. In fact, it was almost double that of the placebo group. This suggests that eating this pepper-derived substance that doesn't burn can have the same potential benefit as hot peppers at least in part by increasing food-induced heat production. They were also able to show that DCT significantly increased fat oxidation, pushing the body to use more fat as fuel. This may help people lose weight when they consume a low-calorie diet by increasing metabolism.

Note, however, that a limitation to this study was that the researchers only tested the effect of DCT on the thermic response to a single meal. Heber and colleagues also point out that that there might be a different effect in lean vs. obese subjects. But to their credit, this was the first study ever conducted to examine the potential health benefits of DCT consumed together with a very low calorie diet. The bottom line: don't be afraid to pile on the peppers.
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No way to avoid Alzheimer's disease?

Many preventive measures for cognitive decline and for preventing Alzheimer's disease -- mental stimulation, exercise, and a variety of dietary supplements -- have been studied over the years. However, an independent panel convened by the National Institutes of Health determined that the value of these strategies for delaying the onset and/or reducing the severity of decline or disease hasn't been demonstrated in rigorous studies.

"Alzheimer's disease is a feared and heart-breaking disease," said Dr. Martha L. Daviglus, conference panel chair and professor of preventive medicine and medicine at Northwestern University, Chicago. "We wish we could tell people that taking a pill or doing a puzzle every day would prevent this terrible disease, but current evidence doesn't support this."

The panel's assessment of the available evidence revealed that progress to understand how the onset of these conditions might be delayed or prevented is limited by inconsistent definitions of what constitutes Alzheimer's disease and cognitive decline. Other factors include incomplete understanding of the natural history of the disease and limited understanding of the aging process in general. The panel recommended that the research community and clinicians collaborate to develop, test, and uniformly adopt objective measures of baseline cognitive function and changes over time.

Although many non-modifiable risk factors have been examined, age is the strongest known risk factor for Alzheimer's disease. Additionally, a genetic variant of a cholesterol-ferrying protein (apolipoprotein E), has strong evidence of association with the risk for developing Alzheimer's disease. Although it is hoped that improved understanding of genetic risk factors may ultimately lead to effective therapies, currently these associations are primarily useful in the clinical research setting.

The panel determined that there is currently no evidence of even moderate scientific quality supporting the association of any modifiable factor -- dietary supplement intake, use of prescription or non-prescription drugs, diet, exercise, and social engagement -- with reduced risk of Alzheimer's disease. The evidence surrounding risk reduction for cognitive decline is similarly limited. Low-grade evidence shows weak associations between many lifestyle choices and reduced risk of Alzheimer's disease and cognitive decline.

Although there is little evidence that these interventions lessen cognitive decline, some are not necessarily harmful and may confer other benefits. However, the panel also emphasized the need for enhanced public understanding that these proposed prevention strategies are currently, at best, only loosely associated with improved outcomes. This means that carefully-designed randomized studies may reveal that these modifiable factors enhance, detract, or have no effect on preventing Alzheimer's disease and cognitive decline.

"These associations are examples of the classic chicken or the egg quandary. Are people able to stay mentally sharp over time because they are physically active and socially engaged or are they simply more likely to stay physically active and socially engaged because they are mentally sharp?" added Dr. Daviglus. "An association only tells us that these things are related, not that one causes the other."

The panel found that certain chronic diseases, such as diabetes and depression, and risk factors such as smoking are associated with increased risk of both Alzheimer's disease and cognitive decline. However, studies have not yet demonstrated that these medical or lifestyle factors actually cause or prevent Alzheimer's disease or cognitive decline, only that they are related.

There is insufficient evidence to support the use of pharmaceuticals or dietary supplements to prevent Alzheimer's disease or cognitive decline. Ongoing studies exploring factors including but not limited to physical activity, omega-3 fatty acids (typically found in fish), antihypertensive medications, and cognitive engagement may provide new insight into Alzheimer's disease and cognitive decline prevention.

The panel made a variety of recommendations to shape the future research agenda and fill identified gaps, while acknowledging that advancing our understanding of these complex conditions in order to develop conclusive, evidence-based prevention recommendations will require considerable time and resources. For example, the panel advocated launching long-term, longitudinal studies to better characterize the natural history and progression of these diseases in the community. They also recommended the establishment of registries for Alzheimer's disease and cognitive decline, modeled on existing registries for cancer.

Extensive research over the past 20 years has provided important insights on the nature of Alzheimer's disease and cognitive decline and the magnitude of the problem. Nevertheless, there remain important and formidable challenges in conducting research on these diseases, particularly in the area of prevention. There are numerous ongoing or planned investigations which may offer promising new insights regarding the causes and prevention of these diseases.

An updated version of the panel's draft consensus statement, which incorporates comments received during the public session, is posted at http://consensus.nih.gov.

The conference was sponsored by the NIH Office of Medical Applications of Research and the National Institute on Aging, along with other NIH and Department of Health and Human Services components. This conference was conducted under the NIH Consensus Development Program, which convenes conferences to assess the available scientific evidence and develop objective statements on controversial medical issues.

The 15-member panel included experts in the fields of preventive medicine, geriatrics, internal medicine, neurology, neurological surgery, psychiatry, mental health, human nutrition, pharmacology, genetic medicine, nursing, health economics, health services research, and family caregiving. A complete listing of the panel members and their institutional affiliations is included in the draft conference statement. Additional materials, including panel bios, photos, and other related resources, are available at http://consensus.nih.gov/2010/alzmedia.htm.

The conference was webcast live and archived. Links to the archived webcast are available at http://consensus.nih.gov/2010/alz.htm.

Individuals interested in obtaining resources for patients and families affected by Alzheimer's disease may wish to contact the National Institute on Aging's Alzheimer's Disease Education and Referral Center at 1-800-438-4380 or http://www.nia.nih.gov/alzheimers.

In addition to the material presented at the conference by speakers and the comments of conference participants presented during discussion periods, the panel considered pertinent research from the published literature and the results of a systematic review of the literature. The systematic review was prepared through the Agency for Healthcare Research and Quality Evidence-based Practice Centers (EPC) program, by the Duke University Evidence-based Practice Center. The EPCs develop evidence reports and technology assessments based on rigorous, comprehensive syntheses and analyses of the scientific literature, emphasizing explicit and detailed documentation of methods, rationale, and assumptions. The evidence report on preventing Alzheimer's disease and cognitive decline is available at http://www.ahrq.gov/clinic/tp/alzcogtp.htm.

The panel's statement is an independent report and is not a policy statement of the NIH or the federal government. The NIH Consensus Development Program was established in 1977 as a mechanism to judge controversial topics in medicine and public health in an unbiased, impartial manner. NIH has conducted 122 consensus development conferences, and 34 state-of-the-science (formerly "technology assessment") conferences, addressing a wide range of issues. A backgrounder on the NIH Consensus Development Program process is available at http://consensus.nih.gov/backgrounder.htm.
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Restraining Calories Boosts Immunity

Scientists funded by the Agricultural Research Service (ARS) found that volunteers who followed a low-calorie diet or a very low-calorie diet not only lost weight, but also significantly enhanced their immune response. The study may be the first to demonstrate the interaction between calorie restriction and immune markers among humans.

The lead researcher, Simin Nikbin Meydani, is director of the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Mass., and also of the HNRCA’s Nutritional Immunology Laboratory.

The study is part of the “Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy” trial conducted at the HNRCA. As people age, their immune response generally declines. Calorie restriction has been shown to boost these immune responses in animal models.

In the study, 46 overweight (but not obese) men and women aged 20 to 40 years were required to consume either a 30-percent or 10-percent calorie-restricted diet for six months.

Prior to being randomly assigned to one of the two groups, each volunteer participated in an initial 6-week period during which measures of all baseline study outcomes were obtained. All food was provided to participants.

For the study, the researchers looked at specific biologic markers. A skin test used called DTH (delayed-type hypersensitivity) is a measure of immune response at the whole body level.

The researchers also examined effects of calorie restriction on function of T-cells--a major type of white blood cell--and other factors on the volunteer’s immune system.

DTH and T-cell response indicate the strength of cell-mediated immunity. One positive was that DTH and T-cell proliferative response were significantly increased in both calorie-restrained groups.

These results show for the first time that short-term calorie restriction for six months in humans improves the function of T-cells.
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Jon's Health Tips - Latest Health Research

Wednesday, April 28, 2010

Previous health research posts:

April 21

April 13

April 1

March 9

February 20

February 3

January 15

So many new research reports have come out this week that I'm doing a new report much sooner than usual (click on links for details.)

Lots of research on what's good for you:
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Vitamin D

and drinking alcohol doesn't reduce value of Vitamin D

100 Percent Fruit Juice

Green tea

Seeing sick people



Just seeing someone who looks sick is enough to make your immune system work harder. (Even looking at a picture works!)



Keeping food off the table



"When we kept the serving dishes off the table, people ate 20% fewer calories. Men ate close to 29% less."




Brown rice



Brown rice may decrease the activity of a protein known to induce high blood pressure and cardiovascular disease.




Exercise

Exercise can forestall osteoporosis

Regular aerobic exercise is good for the brain

But lack of exercise combined with other bad behaviors, is really bad



Four unhealthy behaviors—smoking, lack of physical activity, poor diet and alcohol consumption—appear to be associated with a substantially increased risk of death when combined.Individuals with four compared with zero poor health behaviors had about three times the risk of dying of cardiovascular disease or cancer, four times the risk of dying from other causes and an overall death risk equivalent to being 12 years older.




More good:

Grapes



Findings show grape consumption lowered blood pressure, improved heart function and reduced other risk factors for heart disease and metabolic syndrome




But blueberries are better. Also extra good are sweet potatoes, papaya, kale, raspberries and watercress.



"Americans could improve their phytonutrient intake by choosing to eat more concentrated sources of phytonutrients as well as a wider variety," said Keith Randolph, Ph.D., Technology Strategist for Nutrilite. "For example, grapes are the top contributor of the phytonutrient family of anthocyanidins in most Americans' diets, but blueberries actually contain higher amounts of this phytonutrient. Research suggests anthocyanidins support heart health," Randolph added.

Phytonutrients are compounds that naturally occur in plants and provide a range of potential health benefits from promoting eye, bone and heart health to supporting immune and brain function. It's widely believed that the health benefits that phytonutrients may offer come from the pigments in fruits and vegetables that give these foods their vibrant reds, yellows, greens and other rich colors. Certain fruits and vegetables contain higher levels of these compounds, making them more concentrated and potentially more effective sources of phytonutrients.

For 10 of the 14 phytonutrients included in the analysis, a single food type accounted for approximately two-thirds or more of an individual's intake of the specific phytonutrient, regardless of whether that person was a high or low fruit and vegetable consumer. Based on the current study, the top food sources consumed by Americans for some selected phytonutrients were as follows:

Beta-carotene – carrots
Beta-cryptoxanthin – oranges/orange juice
Lutein/zeaxanthin – spinach
Ellagic acid – strawberries
Isothiocyanates – mustard

For each of these phytonutrients, however, there is a more highly concentrated food that could be chosen instead:

Beta-carotene – sweet potatoes
Sweet potatoes have nearly double the beta-carotene compared to carrots in a single serving.
Beta-cryptoxanthin – papaya
A serving of fresh papaya has roughly 15 times the beta-cryptoxanthin of an orange.
Lutein/zeaxanthin – kale
By substituting cooked kale for raw spinach, it is possible to triple lutein/zeaxanthin intake.
Ellagic acid – raspberries
Serving per serving, raspberries have roughly three times the ellagic acid compared to strawberries.
Isothiocyanates – watercress
Just one cup of watercress as the basis for a salad has about the same level of isothiocyanates as four teaspoons of mustard.



Here's something we all need more of:

Laughter



Norman Cousins first suggested the idea that humor and the associated laughter can benefit a person's health in the 1970s. His ground-breaking work, as a layperson diagnosed with an autoimmune disease, documented his use of laughter in treating himself—with medical approval and oversight—into remission. He published his personal research results in the New England Journal of Medicine and is considered one of the original architects of mind-body medicine.

Laughter helps optimize the hormones in the endocrine system, including decreasing the levels of cortisol and epinephrine, which lead to stress reduction. They have also shown that laughter has a positive effect on modulating components of the immune system, including increased production of antibodies and activation of the body's protective cells, including T-cells and especially Natural Killer cells' killing activity of tumor cells. Their studies have shown that repetitious "mirthful laughter" enhances your mood, decreases stress hormones, enhances immune activity, lowers bad cholesterol and systolic blood pressure, and raises good cholesterol (HDL).




and another supplement that's apparently particularly good for me - I'm an over 50 cyclist:

L-Arginine supplements

Taking L-arginine supplements can improve the cycling ability of over-50s.



Arginine is abundant in many different types of foods, and your body can also make it. Arginine-rich foods include red meat, fish, poultry, wheat germ, grains, nuts and seeds, and dairy products.

Although it has been suggested that arginine may treat asthma, studies in humans have actually found that arginine worsens inflammation in the lungs and contributes to asthma symptoms. Therefore, taking arginine by mouth or by inhalation is not recommended in people with asthma.



And some things bad for me -

Soda (I don't drink it)



Phosphorous in sodas and processed foods accelerates signs of aging.




Sugar (I probably still eat too much)



Consuming a higher amount of added sugars in processed or prepared foods is associated with lower levels of high-density lipoprotein cholesterol (HDL-C, the “good cholesterol”) and higher levels of triglycerides, which are important risk factors for cardiovascular disease.



Sodium (I'm really trying to cut down - I'm buying only unsalted nuts now)



Sodium is a major culprit in our nation's epidemic of high blood pressure—a disease that can start in childhood and will afflict nine out of 10 Americans over the course of their lifetimes. A 35 percent reduction in Americans' average daily sodium intake could save billions of dollars annually on health costs—and save upwards of 90,000 lives—by lowering people's blood pressure, and in turn, their risk of heart disease and stroke.


Some tuna sushi (This is going to be hard for me to figure out and give up)




Mercury levels are significantly higher in bluefin akami (sushi from lean, dark red tuna) and all bigeye tuna samples than in bluefin toro (sushi from fatty tuna) and yellowfin tuna akami samples. This is probably because mercury accumulates differently in different tissue types: mercury has an affinity for muscle and not fatty tissue, so the leanest fish tend to have the highest concentration.

But there also seem to be other factors in play. Although yellowfin tuna is very lean, this species tends to have lower accumulation of mercury, likely because yellowfin are typically smaller than other tuna and are harvested at a younger age.
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Keeping Food Off The Table Reduces Consumption

Tuesday, April 27, 2010

Can eating less be as simple as leaving serving dishes on the stove and off the table? According to a team of researchers from Cornell University, it can.

At this week's Experimental Biology conference in Anaheim, Calif., researchers led by Brian Wansink, director of the Cornell Food and Brand Lab, shared findings of their "Serve Here; Eat There" study of 78 adults.

"We looked at whether serving foods from the kitchen counter, instead of at the table, would reduce the number of times a person refilled his or her plate," Wansink said.

"Quite simply, it is a case of 'out of sight, out of mind,'" he continued. "When we kept the serving dishes off the table, people ate 20% fewer calories. Men ate close to 29% less."

The same strategy can be used to help increase the consumption of healthier foods, Wansink explained.

"If fruits and vegetables are kept in plain sight, we'll be much more likely to choose them, rather than a piece of cake hidden in the refrigerator."

Dining environment, plate and portion size, and other hidden cues that determine what, when and how much we eat are familiar topics in Wansink's work. He is the author of Mindless Eating: Why We Eat More Than We Think.
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low-moderate alcohol consumption does not impair vitamin D status in women

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For as long as our ancestors have been drawing pictograms or writing prose about food and culture, humans have been imbibing various forms of alcohol. Once simply a process by which nutritious beverages could be preserved and stored for later use, there is no doubt that the production and consumption of wines, beers, and spirits now provides integral texture to the fabric of many cultures. However, whether alcoholic drinks provide health benefits is an area of active and on-going debate and research among health and nutrition experts. For instance, moderate alcohol consumption is linked to increased risks of some forms of cancer. Conversely, drinking in reasonable amounts is associated with protection from cardiovascular disease and premature death.

Because many of the studies that have been conducted on this topic have utilized epidemiologic (observational) study designs, they unfortunately cannot provide definitive information on whether alcohol actually influences health or is just related to other lifestyle factors that are actually more physiologically relevant. Indeed, one of the basic tenets of scientific method is the phrase "correlation does not infer causation." In other words, just because people who drink alcohol tend to have fewer heart attacks does not mean that drinking alcohol actually prevents heart disease. In addition, there is a relative dearth of information on low to moderate alcohol consumption and bone health, especially in women. This may be particularly important because alcoholics tend to have weak bones – possibly due to low levels of vitamin D which would hinder absorption of dietary calcium in the small intestine.

To help fill in a knowledge gap in this area, researchers at the National Cancer Institute (NCI) and the US Department of Agriculture ARS Beltsville Human Nutrition Research Center teamed up to rigorously test whether they could demonstrate any negative effects of low to moderate alcohol consumption on bone health in postmenopausal women. As part of the scientific program of the American Society for Nutrition, home to the world's leading nutrition researchers, results from this study will be presented on April 27, 2010 at the Experimental Biology 2010 meeting in Anaheim by Dr. Somdat Mahabir.

This study was part of the Women's Alcohol Study which involved 51 postmenopausal women who did not smoke or use hormone replacement therapy. The research team measured the effects of controlled alcohol consumption during three periods of time. In one of these experimental periods, subjects consumed an alcohol-free beverage once each day. During the other two, they consumed either 15 or 30 g of nearly pure alcohol (Everclear) served up in orange juice. These amounts of alcohol are equivalent to 1 or 2 glasses, respectively, of wine or a bottle of beer. Each study period lasted for 8 weeks, during which time all meals were also provided to the women– either in the USDA's Beltsville Human Nutrition Research Center or provided as "take-out" for the weekends.

The good news for those of us who enjoy a glass or two of wine or beer with dinner or at the football game, is that the scientists did not find any negative effects of either dose of alcohol on circulating levels of vitamin D. Low to moderate intake also did not affect a variety of markers (single-nucleotide polymorphisms or SNPs) which influence alcohol metabolism. These results suggest that the relationship previously documented between alcohol consumption and bone disease in alcoholics may only be seen in very heavy drinkers, or may be due to something other than the alcohol itself.

Dr. Mahabir concluded that "It looks like low to moderate alcohol consumption, at least over the short term, does not harm bone health. Collectively, when all the available published epidemiologic data are considered, it looks like low to moderate alcohol may actually have a beneficial effect." In the end, nutritional scientists once again remind us that all foods and beverages can be part of a healthful diet and urge us to carefully balance the risks against the benefits of our daily dietary choices.
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Merely Seeing Disease Symptoms May Promote Aggressive Immune Response

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Just seeing someone who looks sick is enough to make your immune system work harder, according to a new study in which volunteers looked at pictures of sick people. This may help fight off pathogens, says Mark Schaller from the University of British Columbia who conducted the research. "It seems like it's probably good for the immune system to be responding especially aggressively at times when it looks like you are likely to be coming into contact with something that might make you sick."

Previous research has found that, when people see someone who looks sick, they have a psychological response – they feel disgusted and want to stay away. Schaller, Gregory E. Miller, Will M. Gervais, Sarah Yager, and Edith Chen, all at the University of British Columbia, wanted to go one step farther, to see if looking at sick people might also affect how the immune system itself works.

For this study, published in Psychological Science, a journal of the Association for Psychological Science, volunteers were shown two 10-minute slide shows on two different days. The first one was a neutral slide show, with pictures of furniture. The second was one of two options: a disease slide show, showing people with pox, blowing their noses, sneezing, and so forth, or a slide show of guns. Before and after the slide shows, a blood sample was taken from each volunteer. A little bacteria was added to the blood sample, then the researchers measured the strength of the immune response (specifically, how much of a substance called interleukin-6 the immune cells produced).

People who had looked at the pictures of people sneezing, coughing, or otherwise showing signs of disease had a stronger immune response than people who had looked at pictures of men aiming guns at them. This kind of response to the sight of diseased people may have been evolutionarily adaptive, according to Schaller and his colleagues. Although an aggressive immune response has infection-fighting benefits, it's also costly – it consumes energy and can be temporarily debilitating. It may have been adaptive for the immune system to react especially aggressively when additional information indicates that the threat of infection appears high. According to Schaller, "The things we see around us, such as the sight of sick people, can provide that kind of information. And it makes sense for the immune system to respond to it."
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Better vitamin D status could mean better quality of life for seniors

Monday, April 26, 2010

According to legend, it was The Fountain of Youth that the famed Spanish explorer Ponce de Leon was seeking when he landed on the Floridian coast in 1513. It has long been said that he who drinks from the Fountain will have his youth restored. Without a doubt, the quest for eternal youth is as ancient as any pursuit. However, although we are now living longer than ever, there is now growing concern that quantity of years is not nearly as important as quality of those years. Indeed, as we experience the many joys of living longer, we also must deal with myriad consequences accompanying this aging trend. For instance, osteoporosis, arthritis, and other serious and often painful bone and joint diseases are much more common as we get older. And, not surprisingly, seniors often struggle daily with what was once the simple task of getting around. Hence, the obvious question in today's society concerning our longevity is "What choices can we make to help ease these inconveniences of aging?"

One area of particular interest is the role that diet plays in keeping bones and muscles strong from infancy to old age. For instance, a limited number of studies point to the possibility that optimal intake of vitamin D (the "sunshine" vitamin) might help keep our muscles strong and preserve physical function. Although there are only few longitudinal studies investigating this relationship, their findings have been mixed. To help understand this diet-health association, Dr. Denise Houston from the Sticht Center on Aging at Wake Forest University and her collaborators studied the relationship between vitamin D status and physical function in a group of relatively healthy seniors living in Memphis, TN and Pittsburgh, PA. Their results will be presented on Sunday, April 25 as part of the scientific program of the American Society for Nutrition, composed of the world's leading nutrition researchers, at the Experimental Biology 2010 meeting in Anaheim.

This study was part of the Health, Aging, and Body Composition (Health ABC) study initially designed to assess the associations among body composition, long-term health conditions, and mobility in older adults. For Houston's segment of the investigation, she studied 2788 seniors (mean age: ~75 years) for 4 years. At the beginning of the study, they assessed vitamin D status by analyzing each person's blood for 25-hydroxyvitamin D, a precursor for activated vitamin D. At baseline and then 2 and 4 years later, the research team then determined whether circulating 25-hydroxyvitamin D was related to the participants' physical function. Specifically, they looked at how quickly each participant could walk a short distance (6 meters) and rise from a chair five times as well as maintain his or her balance in progressively more challenging positions. Each participant was also put through a battery of tests assessing endurance and strength.

When the results were tabulated, participants with the highest levels of 25-hydroxyvitamin D had better physical function. And, although physical function declined over the course of the study, it remained significantly higher among those with the highest vitamin D levels at the beginning of the study compared to those with the lowest vitamin D levels. The scientists were not surprised to learn that, in general, vitamin D consumption was very low in this group of otherwise healthy seniors. In fact, more than 90% of them consumed less vitamin D than currently recommended, and many were relying on dietary supplements.

The good news: higher circulating 25-hydroxyvitamin D is related to better physical function in seniors. But it's impossible to tell from this type of research whether increasing vitamin D intake will actually lead to stronger muscles and preserve physical function. This is partly due to the fact that our bodies can make vitamin D if they get enough sunlight. So, it is possible that the participants with better physical function had higher vitamin D status simply because they were able to go outside more often. Indeed, the ominous "chicken-or-the-egg" question can only be answered by carefully controlled clinical intervention trials. Nonetheless, it is possible that getting more vitamin D from foods (like fortified milk and oily fish) or supplements will help maintain youth and vitality as we enjoy longer lifespans. As Houston points out: "Current dietary recommendations are based primarily on vitamin D's effects on bone health. It is possible that higher amounts of vitamin D are needed for the preservation of muscle strength and physical function as well as other health conditions. However, clinical trials are needed to definitively determine whether increasing 25-hydroxyvitamin D concentrations through diet or supplements has an effect on these non-traditional outcomes."

Will vitamin D research lead us to The Fountain of Youth? Probably not. But paying attention to how much vitamin D we get is likely important at every age and will help enhance the "quality" component of life as we enter our senior years.
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Laughter is good for you

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Study finds body's response to repetitive laughter is similar to the effect of repetitive exercise

Laughter is a highly complex process. Joyous or mirthful laughter is considered a positive stress (eustress) that involves complicated brain activities leading to a positive effect on health. Norman Cousins first suggested the idea that humor and the associated laughter can benefit a person's health in the 1970s. His ground-breaking work, as a layperson diagnosed with an autoimmune disease, documented his use of laughter in treating himself—with medical approval and oversight—into remission. He published his personal research results in the New England Journal of Medicine and is considered one of the original architects of mind-body medicine.

Dr. Lee S. Berk, a preventive care specialist and psychoneuroimmunology researcher at Loma Linda University's Schools of Allied Health (SAHP) and Medicine, and director of the molecular research lab at SAHP, Loma Linda, CA, and Dr. Stanley Tan have picked up where Cousins left off. Since the 1980s, they have been studying the human body's response to mirthful laughter and have found that laughter helps optimize many of the functions of various body systems. Berk and his colleagues were the first to establish that laughter helps optimize the hormones in the endocrine system, including decreasing the levels of cortisol and epinephrine, which lead to stress reduction. They have also shown that laughter has a positive effect on modulating components of the immune system, including increased production of antibodies and activation of the body's protective cells, including T-cells and especially Natural Killer cells' killing activity of tumor cells. Their studies have shown that repetitious "mirthful laughter," which they call Laughercise©, causes the body to respond in a way similar to moderate physical exercise. Laughercise© enhances your mood, decreases stress hormones, enhances immune activity, lowers bad cholesterol and systolic blood pressure, and raises good cholesterol (HDL).

As Berk explains, "We are finally starting to realize that our everyday behaviors and emotions are modulating our bodies in many ways." His latest research expands the role of laughter even further.

A New Study: Humor versus Distress, Effect on and Appetite Hormones

Berk, along with his colleague Dr. Jerry Petrofsky at Loma Linda University, and their team have recently completed a new study, which is being presented at the 2010 Experimental Biology conference in Anaheim, CA between April 24-28, 2010.

In the current study, 14 healthy volunteers were recruited to a three-week study to examine the effects that eustress (mirthful laughter) and distress have on modulating the key hormones that control appetite. During the study, each subject was required to watch one 20-minute video at random that was either upsetting (distress) or humorous (eustress) in nature. The study was a cross-over design, meaning that the volunteers waited one week after watching the first video to eliminate its effect, then watched the opposite genre of video.

For a distressing video clip, the researchers had the volunteer subjects watch the tense first 20 minutes of the movie Saving Private Ryan. This highly emotional video clip is known to distress viewers substantially and equally.

For the eustress video, the researchers had each volunteer choose a 20-minute video clip from a variety of humorous options including stand-up comedians and movie comedies. Allowing the volunteers to "self-select" the eustress that most appealed to them guaranteed their maximum humor response.

During the study, the researchers measured each subject's blood pressure and took blood samples immediately before and after watching the respective videos. Each blood sample was separated out into its components and the liquid serum was examined for the levels of two hormones involved in appetite, leptin and ghrelin, for each time point used in the study.

When the researchers compared the hormone levels pre- and post-viewing, they found that the volunteers who watched the distressing video showed no statistically significant change in their appetite hormone levels during the 20-minutes they spent watching the video.

In contrast, the subjects who watched the humorous video had changes in blood pressure and also changes in the leptin and ghrelin levels. Specifically, the level of leptin decreased as the level of ghrelin increased, much like the acute effect of moderate physical exercise that is often associated with increased appetite.

Berk explains that this research does not conclude that humor increases appetite. He explains, "The ultimate reality of this research is that laughter causes a wide variety of modulation and that the body's response to repetitive laughter is similar to the effect of repetitive exercise. The value of the research is that it may provide for those who are health care providers with new insights and understandings, and thus further potential options for patients who cannot use physical activity to normalize or enhance their appetite."

Appetite Loss may have a new Treatment Option

For example, many elderly patients often suffer from what is known as "wasting disease." They become depressed and, combined with a lack of physical activity, lose their appetite and jeopardize their health and well-being. Based on Berk's current research, these patients may be able to use Laughercise© as an alternative, initially less strenuous, activity to regain their appetite.

A similar loss of appetite is often seen in widowers, who typically suffer depression after the loss of a spouse. This often results in decreased immune-system function and subsequent illness in the surviving spouse. Chronic pain patients also suffer from appetite loss due to the chemical changes in their body that cause intolerable discomfort.

While laughter may seem unimaginable in the face of deep depression or intense chronic pain, it may be an accessible alternative starting point for these patients to regain appetite and consequently, improve and enhance their recovery to health.

Berk's current research expands the role of laughter on the human body and whole-person care, but also complicates an already complicated emotion. He acknowledges, "I am more amazed by the interrelatedness of laughter and body responses with the more evidence and knowledge we collect. It's fascinating that positive emotions resulting from behaviors such as music playing or singing, and now mirthful laughter, translate into so many types of [biological] mechanism optimizations. As the old biblical wisdom states, it may indeed be true that laughter is a good medicine."
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Brown rice and cardiovascular protection

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Brown or half-milled rice may decrease the activity of a protein known to induce high blood pressure and cardiovascular disease

Rice is generally thought to be a healthy addition to the diet because it is a source of fiber. However, not all rice is equally nutritious, and brown rice might have an advantage over white rice by offering protection from high blood pressure and atherosclerosis ("hardening of the arteries"), say researchers at the Cardiovascular Research Center and Department of Physiology at Temple University School of Medicine in Philadelphia.

New research by Satoru Eguchi, Associate Professor of Physiology, suggests that a component in a layer of tissue surrounding grains of brown rice may work against angiotensin II. Angiotensin II is an endocrine protein and a known culprit in the development of high blood pressure and atherosclerosis.

The findings are contained in a study conducted by Dr. Eguchi and his colleague at the Temple lab, Akira Takaguri. The research team is also composed of Hirotoshi Utsunomiya and Ryohei Kono of the Department of Pathology, School of Medicine, Wakayana Medical University, Wakayama, Japan; and Shin-ichi Akazawa, Department of Materials Engineering, Nagaoka National College of Technology, Nagaoka, Japan. Dr. Takaguri will present the team's findings at the annual 2010 Experimental Biology conference in Anaheim, CA on April 24-28. This presentation is sponsored by The American Physiological Society (APS; www.the-aps.org). The full meeting program can be viewed at http://experimentalbiology.org/content/default.aspx.

Brown Rice and Angiotensin II

The subaleurone layer of Japanese rice, which is located between the white center of the grain and the brown fibrous outer layer, is rich in oligosaccharides and dietary fibers, making it particularly nutritious. However, when brown rice is polished to make white rice, the subaleurone layer is stripped away and the rice loses some of its nutrients. The subaleurone layer can be preserved in half-milled (Haigamai) rice or incompletely-milled (Kinmemai) rice. These types of rice are popular in Japan because many people there believe they are healthier than white rice.

The Temple team and their colleagues at the Wakayama Medical University Department of Pathology and the Nagaoka National College of Technology Department of Materials Engineering in Japan sought to delve into the mysteries of the subaleurone layer and perhaps make a case for leaving it intact when rice is processed. Because angiotensin II is a perpetrator in such lethal cardiovascular diseases, the team chose to focus on learning whether the subaleurone layer could somehow inhibit the wayward protein before it wreaks havoc.

First, the team removed the subaleurone tissue from Kinmemai rice. Then they separated the tissue's components by exposing the tissue to extractions of various chemicals such as ethanol, methanol and ethyl acetate. The team then observed how the tissue affected cultures of vascular smooth muscle cells. Vascular smooth muscle cells are an integral part of blood vessel walls and are direct victims of high blood pressure and atherosclerosis.

During their analysis, the team found that subaleurone components that were selected by an ethyl acetate extraction inhibited angiotensin II activity in the cultured vascular smooth muscle cells. This suggests that the subaleurone layer of rice offers protection against high blood pressure and atherosclerosis. It could also help explain why fewer people die of cardiovascular disease in Japan, where most people eat at least one rice-based dish per day, than in the U.S., where rice is not a primary component of daily nutrition.

"Our research suggests that there is a potential ingredient in rice that may be a good starting point for looking into preventive medicine for cardiovascular diseases," said Dr. Eguchi. "We hope to present an additional health benefit of consuming half-milled or brown rice [as opposed to white rice] as part of a regular diet."
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Choosing different fruits and vegetables may increase phytonutrient intake

New research suggests

Topping that bowl of cereal with raspberries instead of strawberries, or sautéing kale instead of spinach for dinner can boost phytonutrient intake, which may help decrease risk for certain chronic diseases, including cardiovascular disease, cancer and diabetes.

A study found that despite the availability of a wide range of foods that contain phytonutrients, many Americans are getting phytonutrients from a relatively small number of specific foods, which are not necessarily the most concentrated sources. Top food contributors for several key phytonutrient families in the diet include oranges, orange juice, carrots, grapes, garlic, tomatoes, strawberries, prepared mustard, tea and various soy products, according to the study.

"Americans could improve their phytonutrient intake by choosing to eat more concentrated sources of phytonutrients as well as a wider variety," said Keith Randolph, Ph.D., Technology Strategist for Nutrilite. "For example, grapes are the top contributor of the phytonutrient family of anthocyanidins in most Americans' diets, but blueberries actually contain higher amounts of this phytonutrient. Research suggests anthocyanidins support heart health," Randolph added.

Phytonutrients are compounds that naturally occur in plants and provide a range of potential health benefits from promoting eye, bone and heart health to supporting immune and brain function. It's widely believed that the health benefits that phytonutrients may offer come from the pigments in fruits and vegetables that give these foods their vibrant reds, yellows, greens and other rich colors. Certain fruits and vegetables contain higher levels of these compounds, making them more concentrated and potentially more effective sources of phytonutrients.

Phytonutrient Intake Among Americans

The two groups analyzed in the study include adults who eat the recommended amount of fruits and vegetables, as compared to adults who fail to meet U.S. government guidelines on fruit and vegetable consumption based on two days of intake. Findings suggested that for most phytonutrients, there is little difference in the relative contributions of phytonutrients by food source between groups, although those who meet the recommended five to 13 servings per day were shown to consume greater quantities of certain phytonutrient-rich foods. One key finding of the study concluded that, on average, Americans who consume the recommended amount of fruits and vegetables generally get two to three times more phytonutrients in their diet as compared to people who do not meet fruit and vegetable recommendations. This was true for all but two of the phytonutrients studied. Of note, these data relate to the findings of a previous study conducted by the Nutrilite Health Institute – America's Phytonutrient Report: Quantifying the Gap – that found eight in 10 Americans have a "phytonutrient gap," meaning they are missing out on health benefits provided by phytonutrients given their lack of fruit and vegetable intake.

Power Up Produce

For 10 of the 14 phytonutrients included in the analysis, a single food type accounted for approximately two-thirds or more of an individual's intake of the specific phytonutrient, regardless of whether that person was a high or low fruit and vegetable consumer. Based on the current study, the top food sources consumed by Americans for some selected phytonutrients were as follows:

Beta-carotene – carrots
Beta-cryptoxanthin – oranges/orange juice
Lutein/zeaxanthin – spinach
Ellagic acid – strawberries
Isothiocyanates – mustard

For each of these phytonutrients, however, there is a more highly concentrated food that could be chosen instead:

Beta-carotene – sweet potatoes
Sweet potatoes have nearly double the beta-carotene compared to carrots in a single serving.
Beta-cryptoxanthin – papaya
A serving of fresh papaya has roughly 15 times the beta-cryptoxanthin of an orange.
Lutein/zeaxanthin – kale
By substituting cooked kale for raw spinach, it is possible to triple lutein/zeaxanthin intake.
Ellagic acid – raspberries
Serving per serving, raspberries have roughly three times the ellagic acid compared to strawberries.
Isothiocyanates – watercress
Just one cup of watercress as the basis for a salad has about the same level of isothiocyanates as four teaspoons of mustard.

The overall goal is to encourage Americans to close their "phytonutrient gap" by increasing consumption of all phytonutrient-rich foods. Importantly, by "powering up produce" selection on a regular basis and by seeking a greater variety of fruits and vegetables, phytonutrient intakes can be increased.

"The study reiterates our earlier findings that American adults are missing out on the health benefits of fruits and vegetables by simply not including enough in their diet," said Randolph. "Additionally, these data highlight the importance of not only the quantity, but also the significant impact the quality and variety of the fruits and vegetables you eat can have on your health. All Americans can improve their phytonutrient intake by varying the fruits and vegetables they consume and by focusing on foods that have a higher concentration of certain phytonutrients," he added.
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Grapes reduce risk factors for heart disease and diabetes

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Findings show grape consumption lowered blood pressure, improved heart function and reduced other risk factors for heart disease and metabolic syndrome


Could eating grapes slow what's for many Americans a downhill sequence of high blood pressure and insulin resistance leading to heart disease and type 2 diabetes?

Scientists at the University of Michigan Health System are teasing out clues to the effect of grapes in reducing risk factors related to cardiovascular disease and metabolic syndrome. The effect is thought to be due to phytochemicals -- naturally occurring antioxidants – that grapes contain.

Findings from a new animal study will be presented today at the Experimental Biology convention in Anaheim, Calif., and show encouraging results of a grape-enriched diet preventing risk factors for metabolic syndrome, a condition affecting an estimated 50 million Americans and is often a precursor to type 2 diabetes.

Researchers studied the effect of regular table grapes (a blend of green, red and black grapes) that were mixed into a powdered form and integrated into the diets of laboratory rats as part of a high-fat, American style diet. All of the rats used were from a research breed that is prone to being overweight.

They performed many comparisons between the rats consuming a grape-enriched diet and the control rats receiving no grape powder. Researchers added calories and sugars to the control group to balance the extra calories and sugars gained from getting the grape powder.

After three months, the rats that received the grape-enriched diet had lower blood pressure, better heart function, and reduced indicators of inflammation in the heart and the blood than rats who received no grape powder. Rats also had lower triglycerides and improved glucose tolerance.

The effects were seen even though the grape-fed animals had no change in body weight.

In all, researchers say the study demonstrates that a grape-enriched diet can have broad effects on the development of heart disease and metabolic syndrome and the risk factors that go along with it.

"The possible reasoning behind the lessening of metabolic syndrome is that the phytochemicals were active in protecting the heart cells from the damaging effects of metabolic syndrome. In the rats, inflammation of the heart and heart function was maintained far better," says Steven Bolling, M.D., heart surgeon at the U-M Cardiovascular Center and head of the U-M Cardioprotection Research Laboratory.

The researchers also looked for signs of inflammation, oxidative damage and other molecular indicators of cardiac stress. Again, the rats who consumed the grape powder had lower levels of these markers than rats who did not receive grapes.

There is no well-accepted way to diagnose metabolic syndrome which is really a cluster of characteristics: excess belly fat (for men, a waist measuring 40 inches or more and for women, a waist measuring 35 inches or more); high triglycerides which can lead to plague build-up in the artery walls; high blood pressure; reduced glucose tolerance; and elevated c-reactive protein, a marker for inflammation in the body.

Those with metabolic syndrome are at higher risk for cardiovascular disease and type 2 diabetes.

But the U-M study suggests that it may be possible that grape consumption can change the downhill sequence that leads to heart disease by prolonging the time between when symptoms begin to occur and a time of diagnosis.

"Reducing these risk factors may delay the onset of diabetes or heart disease, or lessen the severity of the diseases," says E. Mitchell Seymour, Ph.D., lead researcher and manager of the U-M Cardioprotection Research Laboratory. "Ultimately it may lessen the health burden of these increasingly common conditions."

Rats were fed the same weight of food each day, with powered grapes making up 3 percent of the diet. Although the current study was supported in part by the California Table Grape Commission, which also supplied the grape powder, the researchers note that the commission played no role in the study's design, conduct, analysis or preparation of the presentation.

Research on grapes and other fruits containing high levels of antioxidant phytochemicals continues to show promise. U-M will further its research this summer when it begins a clinical trial to test the impact of grape product consumption on heart risk factors.

"Although there's not a particular direct correlation between this study and what humans should do, it's very interesting to postulate that a diet higher in phytochemical-rich fruits, such as grapes, may benefit humans," Bolling says.

Bolling says that people who want to lower their blood pressure, reduce their risk of diabetes or help with weakened hearts retain as much pumping power as possible should follow some tried-and-true advice to eat a healthy diet low in saturated fat, trans fat and cholesterol, achieve a desirable weight and increase physical activity.
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4 unhealthy behaviors combine to increase death risk

Four unhealthy behaviors—smoking, lack of physical activity, poor diet and alcohol consumption—appear to be associated with a substantially increased risk of death when combined, according to a report in the April 26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

"Several studies have shown that specific health behaviors, including cigarette smoking, physical inactivity, higher alcohol intake and, to a lesser extent, diets low in fruits and vegetables, are associated with an increased risk of cardiovascular disease, cancer and premature mortality [death]," the authors write as background information in the article. Most studies that examine the effects of these behaviors control for other unhealthy behaviors to identify independent effects. However, several poor lifestyle choices may coexist in the same individual.

"To fully understand the public health impact of these behaviors, it is necessary to examine both their individual and combined impact on health outcomes," write Elisabeth Kvaavik, Ph.D., of University of Oslo, Norway, and colleagues. The researchers interviewed 4,886 individuals age 18 or older in 1984 to 1985. "A health behavior score was calculated, allocating one point for each poor behavior: smoking; fruits and vegetables consumed less than three times daily; less than two hours physical activity per week; and weekly consumption of more than 14 units [one unit equals 8 grams, or about 0.3 ounces] of alcohol (in women) and more than 21 units (in men)."

During an average of 20 years of follow-up, 1,080 participants died—431 from cardiovascular disease, 318 from cancer and 331 from other causes. When compared with participants who had no poor health behaviors, the risk of death from all causes and from each cause increased with each additional behavior.

Individuals with four compared with zero poor health behaviors had about three times the risk of dying of cardiovascular disease or cancer, four times the risk of dying from other causes and an overall death risk equivalent to being 12 years older.
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Exercise can forestall osteoporosis

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The stage for osteoporosis is set well before menopause—but exercise can help rewrite the script, according to Medical College of Georgia researchers.

Declining estrogen levels have long been associated with osteoporosis, but bone density starts to decline years before these levels drop, according to Dr. Joseph Cannon, Kellet Chair in Allied Health Sciences and principal investigator of the National Institute of Aging-funded study. It's during that time that levels of follicle-stimulating hormone, released by the pituitary gland to help regulate ovarian function, actually increase.

Cannon theorizes that higher levels of FSH decrease bone mineral density by increasing cytokines, regulatory proteins produced by white blood cells. One cytokine in particular, interleukin-1, signals certain cells to transform into osteoclasts, which break down and resorb bone. "We hypothesize that the higher levels of FSH decrease bone mineral density by influencing the production of cytokines," said Cannon, who presents his team's research at the American Physiological Society's Experimental Biology 2010 conference in Anaheim, Calif. April 24-28.

After measuring FSH and bone mineral density in 36 women between the ages of 20 to 50, the researchers correlated higher FSH levels with lower bone mineral density. When they incubated FSH with white blood cells isolated from the women, it stimulated production of interleukin-1. Moreover, higher circulating levels of IL-1 correlated with lower bone mineral density, if the levels of interleukin-1 inhibitory factors were taken into account.

Additionally, they found that study participants who exercised more than 180 minutes a week retained greater bone density.

"Our work provides more evidence that physical activity is important for maintaining bone density. It's a case of ’use it or lose it,'" Cannon said, citing his team’s findings that exercise seemed to promote inhibitory factors that help keep interleukin-1 and bone breakdown under control.
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Regular aerobic exercise is good for the brain

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Regular exercise speeds learning and improves blood flow to the brain, according to a new study led by researchers from the University of Pittsburgh School of Medicine that is the first to examine these relationships in a non-human primate model. The findings are available in the journal Neuroscience.

While there is ample evidence of the beneficial effects of exercise on cognition in other animal models, such as the rat, it has been unclear whether the same holds true for people, said senior author Judy L. Cameron, Ph.D., a psychiatry professor at Pitt School of Medicine and a senior scientist at the Oregon National Primate Research Center at Oregon Health and Science University. Testing the hypothesis in monkeys can provide information that is more comparable to human physiology.

"We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain's motor cortex than their sedentary counterparts," Dr. Cameron said. "This suggests people who exercise are getting similar benefits."

For the study, the researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months. Another group of monkeys remained sedentary, meaning they sat on the immobile treadmill, for a comparable time. Half of the runners went through a three-month sedentary period after the exercise period. In all groups, half of the monkeys were middle aged (10 to 12 years old) and the others were more mature (15 to 17 years old). Initially, the middle-aged monkeys were in better shape than their older counterparts, but with exercise, all the runners became more fit.

During the fifth week of exercise training, standardized cognitive testing was initiated and then performed five days per week until week 24. In a preliminary task, the monkeys learned that by lifting a cover off a small well in the testing tray, they could have the food reward that lay within it. In a spatial delay task, a researcher placed a food reward in one of two wells and covered both wells in full view of the monkey. A screen was lowered to block the animal's view for a second, and then raised again. If the monkey displaced the correct cover, she got the treat. After reliably succeeding at this task, monkeys that correctly moved the designated one of two different objects placed over side-by-side wells got the food reward that lay within it.

"Monkeys that exercised learned to remove the well covers twice as quickly as control animals," Dr. Cameron said. "Also, they were more engaged in the tasks and made more attempts to get the rewards, but they also made more mistakes."

She noted that later in the testing period, learning rate and performance was similar among the groups, which could mean that practice at the task will eventually overshadow the impact of exercise on cognitive function.

When the researchers examined tissue samples from the brain's motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. But those blood flow changes reversed in monkeys that were sedentary after exercising for five months.

"These findings indicate that aerobic exercise at the recommended levels can have meaningful, beneficial effects on the brain," Dr. Cameron said. "It supports the notion that working out is good for people in many, many ways."
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Drinking 100 Percent Fruit Juice Is Associated With Improved Diet Quality In Children

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New research shows children and teens who drink 100 percent juice have higher intakes of key nutrients compared to non-consumers

Consumption of 100 percent fruit juice is closely linked to improved nutrient intake and overall diet quality in children and teens, according to new research presented yesterday at the Experimental Biology (EB) 2010 meeting.

Two new studies from researchers at the Louisiana State University Agricultural Center and Baylor College of Medicine clearly highlight the benefits of drinking 100 percent fruit juice. Researchers used data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) to compare the diets of juice drinkers to non-consumers.

According to the findings, children 2-5 years of age who consumed fruit juice had significantly higher intakes of vitamin C, potassium, and magnesium and significantly lower intakes of added sugars compared to non-fruit juice consumers. In addition, higher intake of fruit juice was directly correlated with increased consumption of whole fruits and whole grains.

Children 6-12 years of age showed a similar positive association between intake of 100 percent juice and higher intakes of the key nutrients, as well as dietary fiber. Overall diet quality, as assessed by the Healthy Eating Index (a measure that evaluates conformance to federal dietary guidance) was higher in all fruit juice consumers assessed.

The researchers reported that a significantly higher percentage of non-fruit juice consumers 2-18 years of age failed to meet the recommended levels for several key nutrients, including vitamins A and C and folate, compared to those who drank 100 percent juice. Comparatively, a greater percentage of those in the fruit juice group exceeded Adequate Intake levels for calcium versus non-consumers.

“One hundred percent fruit juice plays an important role in the diets of children and teens, supplying important nutrients during a key period of growth and development,” notes lead researcher Dr. Carol O’Neil. “Drinking 100 percent juice should be encouraged as part of an overall balanced diet.”

The analyses also revealed that mean consumption of fruit juice was well within the American Academy of Pediatrics’ recommended intake levels of 4 to 6 ounces per day for children age 1 to 6 years and 8 to 12 ounces per day for children age 7 to 18 years.

For more information about the research on 100% fruit juice presented at Experimental Biology 2010, please view the summary abstracts below:

Improved nutrient intake and diet quality with 100% fruit juice consumption in children: NHANES 2003–2006

Fruit juice consumption decreases the proportion of children with inadequate intakes of key nutrients: NHANES 2003–2006
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Phosphorous in sodas and processed foods accelerates signs of aging

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New research in the FASEB Journal shows that high levels of phosphate in sodas and processed foods accelerate the aging process in mice and contribute to age-associated complications such as chronic kidney disease

Here's another reason to kick the soda habit. New research published online in the FASEB Journal shows that high levels of phosphates may add more "pop" to sodas and processed foods than once thought. That's because researchers found that the high levels of phosphates accelerate signs of aging. High phosphate levels may also increase the prevalence and severity of age-related complications, such as chronic kidney disease and cardiovascular calcification, and can also induce severe muscle and skin atrophy.

"Humans need a healthy diet and keeping the balance of phosphate in the diet may be important for a healthy life and longevity," said M. Shawkat Razzaque, M.D., Ph.D., from the Department of Medicine, Infection and Immunity at the Harvard School of Dental Medicine. "Avoid phosphate toxicity and enjoy a healthy life."

To make this discovery, Razzaque and colleague examined the effects of high phosphate levels in three groups of mice. The first group of mice was missing a gene (klotho), which when absent, causes mice to have toxic levels of phosphate in their bodies. These mice lived 8 to 15 weeks. The second group of mice was missing the klotho gene and a second gene (NaPi2a), which when absent at the same time, substantially lowered the amount of phosphate in their bodies. These mice lived to 20 weeks. The third group of mice was like the second group (missing both the klotho and NaPi2a genes), except they were fed a high-phosphate diet. All of these mice died by 15 weeks, like those in the first group. This suggests that phosphate has toxic effects in mice, and may have a similar effect in other mammals, including humans.

"Soda is the caffeine delivery vehicle of choice for millions of people worldwide, but comes with phosphorous as a passenger" said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. "This research suggests that our phosphorous balance influences the aging process, so don't tip it."
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Arginine supplements can improve the cycling ability of over-50s

Friday, April 23, 2010

Taking arginine supplements can improve the cycling ability of over-50s. Researchers writing in BioMed Central's Journal of the International Society of Sports Nutrition tested a combination of the amino acid and an antioxidant in sixteen cyclists, finding that it enhanced their anaerobic threshold -- the amount of work done before lactic acid begins to accumulate in the blood.

Zhaoping Li worked with a team of researchers from the University of California, Los Angeles, USA, to carry out the randomized controlled trial. She said, "The loss of exercise capacity with age often results in a reduction in physical fitness and more rapid senescence. A dietary supplement that increases exercise capacity might help to preserve physical fitness by optimizing performance and improving general health and well being in older people."

One way in which older people may reduce their exercise capacity revolves around the signaling molecule nitric oxide (NO), which is involved in many physiological processes, including those related to working out. NO production diminishes in quantity and availability as we age and is associated with an increased prevalence of other cardiovascular risk factors. In the body, NO is created from the amino acid arginine and is inactivated by oxygen free radicals. By supplementing diet with both the precursor and an anti-oxidant, the researchers hoped to support the NO system in the cyclists and thereby enhance performance.

Sixteen cyclists aged between 50 and 73 were randomly assigned to receive either the supplement or dummy placebo pills. After one week of study, the anaerobic threshold of the supplement group increased, while that of the control group did not significantly alter. This increase in anaerobic threshold was preserved at week three. According to Li, "We've demonstrated a 16.7% increase in anaerobic threshold. This indicates a potential role of arginine and antioxidant supplementation in improving exercise performance in elderly."

Arginine is abundant in many different types of foods, and your body can also make it. Arginine-rich foods include red meat, fish, poultry, wheat germ, grains, nuts and seeds, and dairy products.

Although it has been suggested that arginine may treat asthma, studies in humans have actually found that arginine worsens inflammation in the lungs and contributes to asthma symptoms. Therefore, taking arginine by mouth or by inhalation is not recommended in people with asthma.

Here's more - from the US government:


Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;

Coronary artery disease / angina

Early evidence from several studies suggests that arginine taken by mouth or by injection may improve exercise tolerance and blood flow in arteries of the heart. Benefits have been shown in some patients with coronary artery disease and chest pain (called angina). However, more research is needed to confirm these findings and to develop safe and effective doses. B

Critical illness

Some studies suggest that arginine may be beneficial for people with critical or life-threatening illnesses when it is added to nutritional supplements. However, it is unclear what the specific role of arginine is in recovery. Because of the potential for harm, large doses of arginine should be avoided. B

Heart failure

Studies of arginine in patients with chronic heart failure have shown mixed results. Some studies report improved exercise tolerance. Additional studies are needed to confirm these findings. B

Migraine headache

Early studies suggest that adding arginine to ibuprofen (e.g., Motrin® or Advil®) therapy may decrease migraine headache pain. B

Dental pain (ibuprofen arginate)

Some research suggests that ibuprofen-arginate (Spedifen®) may reduce pain after dental surgery faster or more effectively than ibuprofen (e.g., Motrin® or Advil®) alone. More research is needed in this area. C

Diabetes (Type 1/Type 2)

Early studies in humans suggest that arginine supplements may decrease the severity of diabetes. Large, well-designed studies are needed to understand this relationship. C

Diabetic complications

Early studies in humans suggest that arginine supplements may help the body fight some long-term complications of diabetes, including heart disease and nerve damage. Well-designed studies are needed. C

Erectile dysfunction

Early studies have shown that arginine supplements may help treat erectile dysfunction (ED) in men with low nitrate levels in their blood or urine. A combination of L-arginine, glutamate, and yohimbine hydrochloride has been used to treat ED. However, because a combination product was used, and yohimbine hydrochloride is an FDA-approved therapy for this condition, the effects of arginine alone are unknown. More research is needed with arginine alone. C

Gastrointestinal cancer surgery

A combination of arginine and omega-3 fatty acids may reduce the length of hospital stays and infections after surgery in gastrointestinal cancer patients. Other research suggests that arginine, omega-3 fatty acids, and glutamine may boost the immune system and reduce inflammation after surgery. More research with arginine alone is needed.
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Eating too much sugar raises heart disease risk

Wednesday, April 21, 2010

Consuming a higher amount of added sugars in processed or prepared foods is associated with lower levels of high-density lipoprotein cholesterol (HDL-C, the “good cholesterol”) and higher levels of triglycerides, which are important risk factors for cardiovascular disease, according to a study in the April 21 issue of JAMA.

“In the United States, total consumption of sugar has increased substantially in recent decades, largely owing to an increased intake of ‘added sugars,’ defined as caloric sweeteners used by the food industry and consumers as ingredients in processed or prepared foods to increase the desirability of these foods,” the authors write. No known studies have examined the association between the consumption of added sugars and lipid measures, such as HDL-C, triglycerides and low-density lipoprotein cholesterol (LDL-C).

Jean A. Welsh, M.P.H., R.N., of Emory University, Atlanta, and colleagues assessed the association between consumption of added sugars and blood lipid levels in U.S. adults. The study included 6,113 adults from the National Health and Nutrition Examination Survey (NHANES) 1999-2006. Respondents were grouped by intake of added sugars using limits specified in dietary recommendations (less than 5 percent of total calories [reference group], 5 percent to less than 10 percent, 10 percent to less than 17.5 percent, 17.5 percent to less than 25 percent, and 25 percent or more of total calories).

Various measures calculated in the study included average HDL-C, average triglycerides, and average LDL-C levels and adjusted odds ratios of dyslipidemia (abnormal amounts of lipids and lipoproteins in the blood), including low HDL-C levels (less than 40 mg/dL for men; less than 50 mg/dL for women), high triglyceride levels (150 mg/dL or greater), high LDL-C levels (130 mg/dL or greater), or high ratio of triglycerides to HDL-C (greater than 3.8). Results were weighted to be representative of the U.S. population.

The researchers found that daily consumption of added sugars averaged 3.2 ounces (21.4 tsp., 359 calories), which represents 15.8 percent of total daily caloric intake. “This represents a substantial increase from 1977-1978, when added sugars contributed only 10.6 percent of the calories consumed by adults,” the authors write.

Adjusted average HDL-C levels were lower among respondents consuming higher amounts of added sugars: 58.7 mg/dL among those consuming less than 5 percent energy from added sugars, 57.5 mg/dL among those consuming 5 percent to less than 10 percent, 53.7 mg/dL among those con¬suming 10 percent to less than 17.5 percent, 51.0 mg/dL among those consuming 17.5 percent to less than 25 percent, and 47.7 mg/dL among those consuming 25 percent or greater. Among higher consumers (10 percent or greater added sugars) the odds of low HDL-C levels were 50 percent to more than 300 percent greater compared with the reference group (less than 5 percent added sugars).

The researchers also found that higher consumption of added sugars was associated with higher triglyceride levels and higher ratios of triglycerides to HDL-C.

“Monitoring trends in consumption and understanding the effect added sugars have on risk of cardiovascular and other diseases is critically important, because added sugars are a potentially modifiable source of calories,” the authors write. “Added sugars are food additives that can be recognized by consumers and have been proposed for specific labeling on food and beverage packaging. The results of our study demonstrate that increased added sugars are associated with important cardiovascular disease risk factors, including lower HDL-C levels, higher triglyceride levels, and higher ratios of triglycerides to HDL-C.”

“Although long-term trials to study the effect of reducing added sugars and other carbohydrates on lipid profiles are needed, our data support dietary guidelines that target a reduction in consumption of added sugar.”
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Health threat posed by Americans' over-consumption of sodium

Responding to the health threat posed by Americans' over-consumption of sodium, experts in the department of nutrition at Harvard School of Public Health (HSPH) and The Culinary Institute of America (CIA) called today for sodium reduction strategies that are strong and effective—and that maximize the enjoyment people derive from food.

"There is now overwhelming evidence that we must treat sodium reduction as a critical public health priority, much as we did when we discovered the harms of trans fats," said Walter Willett, MD, DrPH, chairman of the department of nutrition, HSPH, and a member of the Institute of Medicine of the National Academy of Sciences. "The food industry tackled the trans fat reduction challenge with remarkable speed. We invite their best creative minds to bring similar leadership to the equally urgent cause of sodium reduction."

This call for action complements the Institute of Medicine's (IOM) release today of a much-anticipated report, Strategies to Reduce Sodium Intake in the United States. Sodium is a major culprit in our nation's epidemic of high blood pressure—a disease that can start in childhood and will afflict nine out of 10 Americans over the course of their lifetimes. A 35 percent reduction in Americans' average daily sodium intake could save billions of dollars annually on health costs—and save upwards of 90,000 lives—by lowering people's blood pressure, and in turn, their risk of heart disease and stroke. But achieving this will take a comprehensive, population-wide effort, one that includes federal leadership to create a level playing field so that all food companies can move in concert toward gradual, steady reduction of sodium levels.

Policy changes need to go hand in hand with practical strategies. That's why scientists from the department of nutrition at HSPH and culinary experts from the CIA have drawn up "Tasting Success with Cutting the Salt: Twenty Five Science-Based Strategies and Culinary Insights." Among the recommendations:

• Produce first: Fill half your plate with fruits and vegetables. Our bodies need more potassium than sodium, and many fruits and vegetables are good sources of potassium. In addition, produce, which is naturally low in sodium, will displace other high-sodium foods on your plate.
• Go nuts for healthy fats in the kitchen: Fat is a great carrier and enhancer of flavor, and using the right fats (including healthy oils, nuts, and avocados) can help make up for any flavor loss from using less salt.
• Know your seasons, and, even better, your farmer. Shop for raw ingredients with maximum natural flavor, thereby avoiding the need to add as much (if any) salt.
• Sear, sauté, and roast. Take the time to learn some simple cooking techniques that can boost flavors and make your cooking less reliant on sodium.
• Spice it up. One of the easiest ways to reduce the need for added salt is through the use of ingredients such as spices, dried and fresh herbs, roots (such as garlic and ginger), citrus, vinegars, and wine.

"Many chefs and food product developers are already hard at work on multipronged initiatives to reduce sodium," said Greg Drescher, CIA's executive director of strategic initiatives and a member of the IOM sodium reduction committee. "We encourage all chefs to think as broadly as possible about ways to reduce sodium, since the sodium issue is not merely about saltiness. It's about flavor, and about the many different strategies chefs and all of us can use to create sensational flavors."

Americans, on average, consume the equivalent of about a teaspoon and a half of salt each day (3,400 milligrams of sodium). The IOM report outlines the steps needed to cut that back to a teaspoon per day (2,300 milligrams of sodium). Doing so will be a major public health achievement, Willett notes, and once we meet that goal, we shouldn't stop there. "The latest research finds that most adults should limit themselves to only 1,500 milligrams of sodium each day, about two-thirds of a teaspoon of salt," Willett says. "To reach that target, we need to make it easy and delicious for consumers to choose foods with less salt."

The top 25 list can be found at "Cutting Salt and Sodium,", HSPH's nutrition website and one of the leading online sources of science-based nutrition information. The website also has questions and answers on the scientific case for sodium reduction, delicious lower-sodium recipes from the CIA, and in-depth coverage of sodium's effects on health.

This collaboration is an outgrowth of a long-running and very successful joint leadership initiative between the department of nutrition at HSPH and the CIA, "Worlds of Healthy Flavors," that annually brings together top nutrition scientists, volume foodservice chefs and operators, and influential culinary experts. With many of today's most urgent diet and health issues having a combination of science, public policy, and taste/flavor components, the department of nutrition at HSPH and CIA view this type of collaboration as essential to achieving real success in fostering healthier food choices. The department of nutrition at HSPH and the CIA also collaborate with the Harvard Medical School Osher Research Center on a groundbreaking, ongoing educational series for physicians and other healthcare professionals, "Healthy Kitchens, Healthy Lives" .
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Mercury is higher in some tuna species


New research provides insight into healthier consumption of sushi






New research showing that that mercury levels are higher in some species of tuna could help consumers minimize their consumption of the silvery metal in their sushi and provide a powerful new tool for regulatory organizations. The new research—combining DNA barcoding at that American Museum of Natural History with analysis of mercury content at Rutgers University—is published in Biology Letters early online edition and shows surprisingly that tuna sushi purchased in supermarkets might be healthier than that from restaurants. The sushi made for supermarkets tends to be yellowfin tuna.



A plate of sushi with several pieces of tuna in the center (dark red is akami; light pink is toro).

"We found that mercury levels are linked to specific species," says Jacob Lowenstein, a graduate student affiliated with the Museum. "So far, the U.S. does not require restaurants and merchants to clarify what species they are selling or trading, but species names and clearer labeling would allow consumers to exercise greater control over the level of mercury they imbibe."

"People who eat fish frequently have a particular need to know which species may be high in contaminants," says Michael Gochfeld, professor at Robert Wood Johnson Medical School. "Some agencies have been afraid that any mention of contaminants will discourage people from eating any fish.

Sushi samples for this research project were taken from 54 restaurants and 15 supermarkets in New York, New Jersey, and Colorado. The results are based on 100 samples, all of which were identified with DNA barcoding as either bigeye tuna (Thunnus obesus), yellowfin tuna (Thunnus albacares), or bluefin tuna species (Thunnus maccoyii, Thunnus orientalis, and Thunnus thynnus). All samples were tested for relative mercury content.



A freshly caught yellowfin tuna is weighed en route to Japan at Suisan fish market in Hilo, Hawaii.


Combining mercury content and species identification in this study shows that all species exceed or approach levels permissible by Canada, the E.U., Japan, the U.S., and the World Health Organization. Mercury levels are significantly higher in bluefin akami (sushi from lean, dark red tuna) and all bigeye tuna samples than in bluefin toro (sushi from fatty tuna) and yellowfin tuna akami samples. This is probably because mercury accumulates differently in different tissue types: mercury has an affinity for muscle and not fatty tissue, so the leanest fish tend to have the highest concentration.

But there also seem to be other factors in play. Although yellowfin tuna is very lean, this species tends to have lower accumulation of mercury, likely because yellowfin are typically smaller than other tuna and are harvested at a younger age. Furthermore, yellowfin are tropical and do not thermoregulate like the warm-blooded bigeye tuna and bluefin tuna. Because bigeye and bluefin species eat three times more than yellowfin to maintain their energy level, they might bioaccumulate, or slowly increase the level of toxins over time.

"Although levels are highest in top-level predatory fish, some fish that are lower on the food chain have high levels," says Joanna Burger, professor at Rutgers University. "The levels of mercury in some tuna are sufficiently high to provide a health risk both to the fish themselves and to the predators that eat them, including humans, particularly those who eat fish frequently."

"We show how you can use DNA as a tool to uncover patterns of species-specific bioaccumulation," says Sergios-Orestis Kolokotronis, a geneticist at the Sackler Institute for Comparative Genomics at the Museum. "This is one of first applications of DNA barcodes in a non-academic setting—using this method in any human health context and not just for determining whether barcodes can quickly and accurately identify a species."
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Fish oil supplements provide no benefit to brain power

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The largest ever trial of fish oil supplements has found no evidence that they offer benefits for cognitive function in older people.

The OPAL study investigated the effects of taking omega-3 long-chain polyunsaturated fatty acid supplements over a two year period on the cognitive function of participants aged 70-80 years.

The number of people with cognitive impairment is rising and it is estimated that by 2040, more than 81 million people globally will have dementia.

Some studies have suggested that high intakes of omega-3 fatty acids, most commonly found in oily fish, are important for the maintenance of good cognitive health in later life.

The OPAL (Older People And omega-3 Long-chain polyunsaturated fatty acids) study, published today in the American Journal of Clinical Nutrition, was a randomised controlled trial led by Alan Dangour, Senior Lecturer at the London School of Hygiene & Tropical Medicine and colleagues.

The study enrolled 867 participants aged 70-80 years from General Practice clinics in England and Wales. Trial participants who all had good cognitive health at the start of the study were randomly assigned into two groups, one of which received fish oil capsules while the other group received a placebo for two years. Cognitive function was assessed at the start and end of the study by trained research nurses using a series of paper and pencil tests of memory and concentration.

After two years, those participants receiving fish oil capsules had significantly higher levels of omega-3 fatty acids in their blood than those participants receiving placebo capsules. However, cognitive function did not change over the course of the study in either group of participants and there was no evidence that the consumption of omega-3 fatty acids had a benefit for cognitive function in older people.

Dr. Alan Dangour urges caution in interpreting these results: "From the data we have collected in the OPAL study there is no evidence of an important benefit for memory or concentration of increased omega-3 fatty acid consumption over a two year period among older people with good cognitive health. However, it is important to keep in mind that poor cognitive function can take many years to develop and although this is the longest trial of its kind ever conducted, it may be that it was not long enough for any true beneficial effects to be detected among this healthy cohort of older people".
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Green tea may help fight glaucoma and other eye diseases

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Scientists have confirmed that the healthful substances found in green tea — renowned for their powerful antioxidant and disease-fighting properties — do penetrate into tissues of the eye. Their new report, the first documenting how the lens, retina, and other eye tissues absorb these substances, raises the possibility that green tea may protect against glaucoma and other common eye diseases. It appears in ACS' bi-weekly Journal of Agricultural and Food Chemistry.




Green tea contains healthful substances that can penetrate eye tissues, raising the possibility that the tea may protect against glaucoma and other eye diseases.


Chi Pui Pang and colleagues point out that so-called green tea "catechins" have been among a number of antioxidants thought capable of protecting the eye. Those include vitamin C, vitamin E, lutein, and zeaxanthin. Until now, however, nobody knew if the catechins in green tea actually passed from the stomach and gastrointestinal tract into the tissues of the eye.

Pang and his colleagues resolved that uncertainty in experiments with laboratory rats that drank green tea. Analysis of eye tissues showed beyond a doubt that eye structures absorbed significant amounts of individual catechins. The retina, for example, absorbed the highest levels of gallocatechin, while the aqueous humor tended to absorb epigallocatechin. The effects of green tea catechins in reducing harmful oxidative stress in the eye lasted for up to 20 hours. "Our results indicate that green tea consumption could benefit the eye against oxidative stress," the report concludes.
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