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August 2010
Score another disappointment for the hoped-for benefits of B vitamin supplements in protecting the heart and circulatory system. Since B vitamins combat homocysteine, an amino acid known to be a risk factor for vascular woes, it makes sense that extra B vitamins might reduce the risk of stroke, heart attack and vascular death. But in a new trial conducted with more than 8,000 patients who'd previously suffered a stroke or mini-stroke, B vitamin pills produced no better results than placebo. The supplements contained 2 mg of folic acid, 25 mg of vitamin B6 and 0.5 mg of vitamin B12. After an average follow-up of 3.4 years, there was no significant difference in stroke, heart attack or vascular death between those getting the B vitamins and a control group — even though the supplements did succeed in lowering homocysteine levels. "These results do not support the use of B vitamins to prevent recurrent stroke," researchers concluded. — The Lancet Neurology…
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July 2010
When dieting to lose weight — like 1 in 3 Americans — you're not just cutting out calories; you're also omitting vitamins, minerals and other nutrients that tag along with those calories. To test these nutritional effects of popular weight-loss plans, Stanford University scientists randomly assigned 300 overweight or obese women to one of four diets: Atkins, Zone, LEARN and Ornish. By repeatedly quizzing the women on what they'd actually eaten, researchers were able to calculate their vitamin and nutrient intake from food. While cutting an average of 500 daily calories, overall the women also reduced their intake of 12 of the 17 nutrients measured, putting some at risk of deficiency. The reduction in dietary vitamin E was most pronounced, with more than 65% of the dieters not getting enough. One surprise: Women on the Zone diet actually boosted their intake of vitamins A, E, C and K, while seeing no dip in other nutrients. Researchers said that finding demonstrated the benefits of a regimen, like the Zone plan, that encourages moderate but not extreme carbohydrate reductions — cutting back on added sugars and refined grains while keeping beans, greens and other veggies. — American Journal of Clinical Nutrition…
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July 2010
How's that again? You may need more folate to help prevent hearing loss? That's the finding of the Blue Mountains Eye Study, which adds to a small but growing body of evidence linking low blood levels of B vitamins, notably folate, to risk of age-related hearing loss. Australian researchers compared blood levels of folate, vitamin B12 and the amino acid homocysteine to incidence of hearing loss among 2,956 people ages 50 and up. Those with the lowest levels of folate were 34% more likely to suffer hearing loss. People with the most homocysteine — an amino acid, linked to other health problems, that's countered by B vitamins — were at 64% greater risk. Elevated homocysteine levels have been linked to adverse effects on blood flow in the inner ear, which could be a factor in hearing loss with age. No association was seen between B12 and hearing loss. To make sure you're getting enough folate (vitamin B9), eat lots of leafy green vegetables, chick peas, lentils and products made with fortified grains. — Journal of Nutrition…
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July 2010
Previous studies have suggested that B vitamins might help protect against depression, but these were mostly snapshots at a single point in time. Now a new study connects B-vitamin intake among 3,500 seniors, initially free of depression, over a span of 12 years: For every 10-milligram increase in daily vitamin B6 from food and supplements, risk of developing depression declined by 2%. The same was true for every additional 10 micrograms of vitamin B12. Folate, another B vitamin previously linked to lower depression incidence, was not associated with reduced risk; researchers speculated this may be because folate deficiency is rare in the US, thanks to fortified grains and cereals. While cautioning that the findings don't show cause and effect — adequate B vitamin intake might, for example, simply be a sign of an overall healthy diet — researchers said the study bolsters the case that relatively low B vitamin intake might be a risk factor for depression. — American Journal of Clinical Nutrition
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June 2010
Getting plenty of B vitamins, especially B6, may reduce your risk of lung cancer, the world's most common cause of cancer death — even if you've never smoked. A study involving nearly 400,000 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) reports that higher blood levels of vitamin B6 were associated with reduced rates of lung cancer regardless of smoking status. Higher levels of the essential amino acid methionine, found in most proteins, and folate were also linked to lower risk, although the folate connection was seen only in former and current smokers. Overall, above-average levels of B6 and methionine were associated with at least a 50% reduction in the risk of developing lung cancer. Combined with higher folate levels, the risk reduction climbed to 67%. Foods high in vitamin B6 include fortified breakfast cereal, potatoes, bananas, garbanzo beans, trout and lean beef and pork. — JAMA
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April 2010
Could multivitamins, which millions of women take daily as "insurance" for a healthy diet, actually increase the risk of breast cancer? That's the suggestion of a large new Swedish study — though researchers were quick to caution that their observational study can't show a cause-and-effect relationship. The study followed more than 35,000 older women (ages 49 to 83 at baseline) over an average of 10 years, during which 974 participants were diagnosed with breast cancer. A little over a quarter of the women reported regularly taking multivitamins at the start of the study. After adjusting for known risk factors, multivitamin users were 19% more likely to develop breast cancer. While there's no way to know if the supplements actually contributed to the cancers, researchers said such an effect is "biologically plausible" and further investigation is warranted. In any case, the Swedish team added, "If you eat a healthy and varied diet, there is no need to take multivitamins." — American Journal of Clinical Nutrition…
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March 2010
If a new Chinese study can be confirmed by further clinical trials, expect multivitamin manufacturers to start touting the supplements for weight loss and cholesterol benefits. The 26-week, randomized, double-blind trial divided 97 obese Chinese women, ages 18-55, into three groups: One got a daily multivitamin, a second group received only a calcium supplement, and the third was given an identical-looking placebo. Among the 87 women who completed the study, those in the multivitamin group saw significantly lower body weight, BMI, fat mass, total cholesterol and LDL (bad) cholesterol, along with higher HDL (good) cholesterol and resting energy expenditure, a measure of metabolism. The calcium group saw only improvements in LDL and HDL, though these were significant compared to the placebo group. Researchers concluded, "The results suggest that, in obese individuals, multivitamin and mineral supplementation could reduce body weight and fatness and improve serum lipid profiles, possibly through increased energy expenditure and fat oxidation." — International Journal of Obesity
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March 2010
The fluorescent lighting in supermarkets not only makes produce look tastier — it can even make some greens healthier. USDA scientists report that continuous lighting like that in supermarkets actually boosts the nutritional value of fresh spinach. Supermarkets often display fresh spinach in clear plastic containers at around 39 degrees Fahrenheit in showcases that may be exposed to fluorescent light 24 hours a day. Researchers wondered how this might affect spinach's nutritional value, so they exposed fresh spinach leaves to continuous light or darkness during simulated retail storage conditions. Spinach stored in light for as little as three days had significantly higher levels of vitamins C, K and E and folate, plus higher levels of the healthful carotenoids (plant pigments) lutein and zeaxanthin. After nine lit-up days, levels of folate and vitamin K doubled in some spinach varieties. By contrast, spinach leaves kept in the dark tended to have declining or unchanged levels of nutrients. The finding could lead to improved ways of preserving and enhancing the nutritional value of spinach and perhaps other veggies. — Journal of Agricultural and Food Chemistry…
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January 2010
High-dose vitamin C supplements, supposed to ward off infections and even fight cancer, may be increasing your risk for cataracts. A Swedish study of nearly 24,600 women over more than eight years has found that those taking vitamin C supplements averaging 1,000 milligrams were about 25% more likely to have age-related cataracts removed. Nearly 1,300 of the women, ages 49 to 83, had cataracts removed during the course of the study. Those who took no dietary supplements were least likely to have cataracts, followed by women who reported taking only multivitamins, which generally have much lower amounts of vitamin C. Although a relatively small group, the women taking high-dose vitamin C pills represented a disproportionate share of cataract cases, even after adjusting for other known risk factors. Researchers cautioned that the findings don't apply to dietary vitamin C from fruits and vegetables, only the mega-doses found in supplements. — American Journal of Clinical Nutrition
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December 2009
The American Dietetic Association (ADA) says a nutritious diet, not pills, is the best way to promote health and reduce the risk of disease. In a new position statement sure to rile the $23 billion dietary supplements industry, the ADA stated, "The best nutrition-based strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of nutrient-rich foods." Citing concerns that consumers lacking information on the safety and effectiveness of dietary supplements, the association called on its membership to keep abreast of research findings on supplements and help educate the public. The position paper did add, "Additional nutrients from supplements can help some people meet their nutrition needs as specified by science-based nutrition standards such as the Dietary Reference Intakes (DRI)." Sales of most supplements grew in 2007, the most recent year for which figures are available, including 3.9% increase in sales of multivitamins, the most popular choice.
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December 2009
Aspirin, in low doses like those taken to prevent cardiovascular disease, does not significantly reduce the risk of age-related macular degeneration (AMD), according to results from the Women's Health Study. Some studies have suggested a link between cardiovascular risk factors and AMD, the leading cause of blindness among older Americans, leading to speculation that aspirin might help prevent AMD by improving blood flow. Researchers analyzed 10 years of data on nearly 40,000 women, half of whom took 100 milligrams of aspirin every other day to test heart-health benefits. Aspirin takers experienced 111 cases of visually significant AMD, compared to 134 in a placebo group. That difference, although 18%, was not enough to be statistically significant because of the small number of AMD cases. A similar slight difference in favor of aspirin was seen in risk of advanced AMD, but the placebo group had slightly fewer overall cases of AMD, with or without vision impairment. Those in the aspirin group who also reported taking multivitamins at the study's start appeared to benefit less from the aspirin. — Ophthalmology
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October 2009
Even as some dietary supplements are under fire for inflated health claims and safety concerns, the US Food and Drug Administration (FDA) has thrown a lifeline to the embattled supplements industry with a new consumer advisory stating "there are many good reasons" to take extra vitamins. Barbara Schneeman, PhD, director of the FDA's Office of Nutritional Products, Labeling and Dietary Supplements, said, "Supplements can be useful when they fulfill a specific identified nutrient need that can't be met by food or is not being met through normal food intake." Examples cited by the FDA included iron and folic acid for pregnant women, B12 for people over 50 (who may not be as able to absorb it from food), and vitamin D for those with darker skin or insufficient exposure to sunlight. Schneeman stressed, "It's really important to remember that supplements can't displace a healthful diet — that's the important nutritional strategy." The agency also warned consumers against "chasing the latest headlines" and using supplements as a "quick fix." Take only the recommended amounts, the FDA advised, and beware of supplement claims that seem too good to be true. — FDA
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July 2009
Antioxidant vitamins and resistance-training exercises could help postmenopausal women protect against bone loss. In a small six-month pilot study, Canadian researchers found that women taking supplements of vitamin E and C and/or exercising suffered no loss of bone-mineral density (BMD) in the hip or spine, while a control group did see bone deterioration. The study split 34 women, average age 66.1, into four groups: antioxidant supplements (600 mg vitamin E plus 1,000 mg vitamin C), antioxidants plus exercise, placebo plus exercise, and placebo with no exercise. Only the placebo group not also on an exercise regimen experienced significant BMD loss, at the spine. The antioxidants plus exercise group saw no additional benefits from the combination. While cautioning that further research is needed, the scientists pointed to Tufts research published earlier this year that showed intake of other antioxidants—carotenoids, especially lycopene—similarly was associated with reduced bone loss.—Osteoporosis International
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June 2009
Tufts researchers have further advanced the case for omega-3 fatty acids as a weapon against age-related macular degeneration (AMD), the leading cause of vision loss among older Americans. According to newly published research, a diet high in omega-3s—found in fatty fish such as salmon—can reduce the progression of AMD by about 25%. Scientists at Tufts' HNRCA Laboratory for Nutrition and Vision Research analyzed data on 2,924 participants in the Age-Related Eye Disease (AREDS) study, which concluded that antioxidant vitamins could reduce the risk of AMD. That study didn't directly involve omega-3s, but did collect information on participants' diets. So the Tufts team compared dietary consumption of foods high in omega-3s with the progression of AMD. Those in the highest one-fourth of intake of DHA (more than 64mg a day), one of two key omega-3s found in fish, were at 27% lower risk of AMD progression than those with the lowest DHA in their diets. The group consuming the most of the second key omega-3, EPA (more than 42.3mg a day), were at 26% reduced risk.—British Journal of Ophthalmology…
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May 2009
That saying about too much of a good thing may apply to high-dose supplements of carotenoids—beta-carotene, retinol and lutein. In doses higher than found in multivitamins, long-term use of carotenoid supplements may increase the risk of lung cancer, especially among smokers and former smokers. In results from the Vitamins and Lifestyle (VITAL) study of 77,126 subjects ages 50 to 76, all three types of carotenoid pills raised the risk of the most common type, non-small-cell lung cancer: retinol by 80%, lutein by 2.5 times and beta-carotene by more than 3-fold. Higher risk of overall lung cancer was associated with retinol and lutein. Similar risks were not seen for another carotenoid supplement, lycopene. Carotenoids from dietary sources actually tend to lower lung-cancer risk, researchers noted; it's possible that the body may absorb these nutrients more readily from supplements, however, and that high doses interfere with natural processes that protect against lung cancer.—American Journal of Epidemiology
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May 2009
Controversial new research in Germany suggests that supplements of antioxidants such as vitamins C and E may block the metabolic benefits of exercise and could even increase diabetes risk. Researchers compared two groups of exercisers, one of which received 1,000 mg of vitamin C and 400 IU of vitamin E daily. After four weeks, the group getting antioxidant vitamins showed no improvement in insulin sensitivity—a normal diabetes-fighting benefit of exercise. When exercise causes muscle cells to burn glucose, oxygen gets consumed much as in a fire; some highly reactive oxygen molecules escape in this process, but the body has natural mechanisms to mop them up. Researchers theorized that the antioxidants might short-circuit the body's own defenses against this "free-radical" oxygen. "If you exercise to promote health," they concluded, "you shouldn't take large amounts of antioxidants." Natural antioxidants in foods rather than pills, however, are in lower doses and come with other nutritional benefits.—Proceedings of the National Academy of Sciences
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May 2009
Rich in heart-healthy omega-3 fatty acids, salmon swam into first place in a new survey of New York nutritionists asked to name foods they'd recommend as not only nutritious but offering distinct health benefits and good value. The poll of members in the New York State Dietetic Association ranked oats number-two because of high fiber, "a powerhouse nutrient, known for aiding with digestion [and which] also helps fight disease, and may lower the risk for high cholesterol, heart disease, diabetes and cancer." Coming in third were blueberries, rich in antioxidants and vitamins, for their "ability to protect the body against the damaging effects of free radicals and the chronic diseases associated with the aging process." Rounding out the nutritionists' top-five foods were two dairy products: low-fat milk, for its calcium and vitamin D content, and low-fat yogurt with added probiotics, which aid digestion.—NYSDA…
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April 2009
Relief for at least some migraine sufferers might be as simple as taking a B-vitamin supplement. In a new Australian clinical trial, a daily dose of 2 mg of folic acid, 25 mg of vitamin B6 and 400 micrograms of B12 cut migraine disability in half, while also reducing the frequency and severity of headaches. Previous studies had associated some migraine attacks with a genetic dysfunction that leads to higher levels of the amino acid homocysteine—which B vitamins have been shown to lower. So researchers split 52 volunteers into two groups, one receiving the B vitamins and the other getting a placebo. After six months, the vitamin group showed a 39% reduction in homocysteine levels and significant improvements in migraine attacks, while the placebo group showed no changes.—Pharmacogenetics and Genomics…
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April 2009
That saying about too much of a good thing may apply to high-dose supplements of carotenoids—beta-carotene, retinol and lutein. In doses higher than found in multivitamins, long-term use of carotenoid supplements may increase the risk of lung cancer, especially among smokers and former smokers. In results from the Vitamins and Lifestyle (VITAL) study of 77,126 subjects ages 50 to 76, all three types of carotenoid pills raised the risk of the most common type, non-small-cell lung cancer: retinol by 80%, lutein by 2.5 times and beta-carotene by more than 3-fold. Higher risk of overall lung cancer was associated with retinol and lutein. Similar risks were not seen for another carotenoid supplement, lycopene. Carotenoids from dietary sources actually tend to lower lung-cancer risk, researchers noted; it's possible that the body may absorb these nutrients more readily from supplements, however, and that high doses interfere with natural processes that protect against lung cancer.—American Journal of Epidemiology
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March 2009
Taking a combination of vitamin B6, vitamin B12 and folic acid appears to decrease the risk of age-related macular degeneration (AMD) in women, according to a clinical trial involving 5,442 women over more than 7 years. Researchers randomly assigned the women to receive either supplements or a placebo. Those in the supplement group were 34% less likely to develop AMD and 41% less at risk for AMD that significantly impaired vision. Benefits from the supplements began to emerge two years after the study began. Though stopping short of recommending B vitamin and folic acid pills, researchers called the trial findings "the strongest evidence to date in support of a possible beneficial effect of folic acid and B vitamin supplements in AMD prevention." AMD is the leading cause of blindness among older Americans.—Archives of Internal Medicine…
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February 2009
Looking to cut household expenses in tough times? You might want to eye that pricey bottle of multivitamins. The largest study ever of multivitamin use in older women—combining four studies totaling more than 250,000 postmenopausal women—has found that the supplements failed to reduce the risk of most common cancers, cardiovascular disease or overall mortality. Researchers analyzed data from the Women's Health Initiative over an average of about eight years; 41.5% of participants took multivitamins. Those taking the pills showed no significant difference in risk compared to women not taking multivitamins.—Archives of Internal Medicine
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January 2009
Soda pop is not a health drink—no matter what Diet Coke Plus would like you to think. The US Food and Drug Administration (FDA) has issued an official warning letter to the Coca-Cola Co., challenging claims that the fortified diet soda is "a good source of vitamins B3, B6 and B12, and the minerals zinc and magnesium." The agency said, "The FDA does not consider it appropriate to fortify snack foods such as carbonated beverages." Coke responded, "We believe the label on Diet Coke Plus complies with FDA's policies and regulations."—FDA
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November 2008
Not only don't supplements of selenium and vitamin E prevent prostate cancer, as researchers had hoped, the extra vitamins may increase other health risks. The National Cancer Institute is stopping a major trial of selenium and vitamin E's possible benefits against prostate cancer, the SELECT study, involving more than 35,000 men ages 50 and up, scheduled to run through 2011. To date, vitamin E users were actually slightly more prone to prostate cancer, and those in the selenium-only group were at slightly greater risk of diabetes. The increased risks could be coincidence, but combined with the lack of benefit that data was enough to pull the plug on the study.--National Cancer Institute…
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November 2008
Don't count on antioxidant vitamin pills to protect your heart. A eight-year
study of 14,641 men, average age 64, concludes that neither vitamin C nor
vitamin E supplements was more effective than a placebo in preventing heart
disease. Unlike most previous studies that tested vitamins C and E in
combination with other antioxidants, this new research investigated each
separately--but with similarly disappointing results. "Our findings add to
the growing consensus about vitamin E and C's lack of cardiovascular
protection," the scientists commented.Journal of the American Medical Association
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