| |
August 2010
That weight-loss supplement in your medicine cabinet may contain more than you bargained for. The US Food and Drug Administration announced a recall of three products marketed as dietary supplements by the EZVille company that actually contain undeclared prescription-drug ingredients. Two weight-loss supplements — Solo Slim and Solo Slim Extra Strength — were found to contain sibutramine, a prescription weight-loss medication sold under the brand name Meridia. In patients with a history of cardiovascular disease, sibutramine has been known to increase the risk of stroke and heart attack. Another EZVille supplement, Revivexxx Extra Strength, touted for male sexual enhancement, turns out to contain an unlabeled dose of the drug tadalafil — better known as Cialis. The products were sold online and in retail stores without a prescription. EZVille said it has not received any reports of adverse events related to the recalled products.…
Read>>
|
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…
Read>>
|
July 2010
Among a medicine-cabinet full of supplements tested in a large, 7-year study, only one was associated with a reduced risk of breast cancer: fish oil. Those participants in the VITAL study of 35,016 postmenopausal women who regularly took fish-oil supplements were 32% less likely to develop breast cancer than non-users. No other supplement studied showed a similar connection, including glucosamine, chondroitin, grapeseed, black cohosh, soy, St. John's wort, ginseng, garlic, ginkgo biloba and coenzyme Q10. It's plausible that the omega-3 fatty acids in fish oil could reduce inflammation, which plays a part in cancer development. But scientists cautioned that the study wasn't designed to prove cause and effect. They also noted one catch to the results: Women with a history of coronary artery disease who took fish-oil pills, most often used to protect against heart disease, were actually more likely to develop breast cancer. Overall, those cases were more than counterbalanced by reduced cancer risk among women without a history of coronary heart disease. — Cancer Epidemiology, Biomarkers & Prevention
…
Read>>
|
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
…
Read>>
|
July 2010
Plant sterols and stanols — naturally occurring compounds that block the absorption of cholesterol — are emerging as a potent new weapon in the battle against heart disease. New findings by Dutch and German scientists show that higher levels of plant stanols produce comparably greater reductions in unhealthy LDL cholesterol. Although most recommendations call for doses of about 2 grams of plant sterols or stanols daily (either as supplements or in fortified foods such as juice and spreads), the study found benefits from daily consumption as high as 9 grams. In testing with 93 healthy subjects with slightly elevated cholesterol, up to 9 grams daily of plant stanols reduced blood levels of LDL cholesterol by up to 17.4%. An editorial accompanying the findings noted, "This raises the question of whether dietary phytosterols, 'natural' products, should be used rather than larger doses of statins or other drugs. These sterols probably would avoid some of the side effects of added drugs." — American Journal of Clinical Nutrition…
Read>>
|
June 2010
Evidence keeps adding up that vitamin K, one of the lesser-known weapons in the nutrient arsenal, might help combat diabetes. A previous Tufts clinical trial found that supplements of the most common form of the vitamin, K1, found naturally in leafy greens and other vegetables, reduced the risk of insulin resistance in older men, thereby helping to protect against diabetes. Now a Dutch observational study suggests that another form of the vitamin, K2, found in meat, cheese and the Japanese food natto (made from fermented soybeans), may reduce diabetes risk. Researchers followed 38,094 men and women, ages 20-70, for an average 10.3 years, during which 918 cases of type-2 diabetes were diagnosed. While higher vitamin K1 intake was non-significantly associated with a lower risk of diabetes, the biggest connection was seen for K2: With every extra 10 micrograms, risk of diabetes dropped 7%. Vitamin K may be effective against diabetes, Tufts researchers have theorized, by suppressing inflammation. — Diabetes Care
…
Read>>
|
June 2010
Undercover agents from the Government Accountability Office (GAO), posing as elderly customers, have busted a host of deceptive and even dangerous marketing practices by sellers of herbs and other supplements. According to a GAO report, "The most egregious practices included suspect marketing claims that a dietary supplement prevented or cured extremely serious diseases, such as cancer and cardiovascular disease." Under the Dietary Supplement Health and Education Act of 1994 (DSHEA), the Food and Drug Administration (FDA) does not approve dietary supplements before they go on the market, unlike prescription drugs. The Federal Trade Commission (FTC) regulates the marketing of supplements, which are forbidden from claiming to treat medical conditions. Investigators, in the guise of elderly buyers in stores or on the phone, also were given dangerously erroneous information about interactions between supplements and medications, such as those that raise the risk of internal bleeding. Others were advised they could drop their prescription drugs and take herbal remedies instead.…
Read>>
|
May 2010
Can your body really absorb the vitamin D in fortified orange juice, given that the vitamin dissolves in fat (as in fortified milk) but not water? A new study (funded by Coca-Cola, which makes Minute Maid juice) says yes. Researchers recruited more than 100 adults and divided them into six groups receiving various combinations of OJ fortified with 1,000 IU of vitamin D, supplements of vitamin D, and placebo drinks and pills. When blood levels were tested at the start of the study, 64% of participants were deficient in vitamin D. After 11 weeks, all those getting extra vitamin D saw increases in blood levels, and there was no difference between those receiving it in pills or juice. But there's one catch: You can't buy OJ fortified with 1,000 IU of vitamin D, because government regulations limit it to 100 IU per serving. That may change, however, after the federal dietary guidelines are updated later this year. — American Journal of Clinical Nutrition
…
Read>>
|
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…
Read>>
|
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
…
Read>>
|
March 2010
Does extra calcium and vitamin D — already known to boost bone health — also protect against heart disease and death? Science continues to answer with a firm "maybe, maybe not." A new review of 17 previous studies looking for a link between calcium and vitamin D supplements concludes that "the existing evidence is quite sparse." While extra vitamin D reduced the risk of death from heart disease and stroke in a few studies, those mostly involved people already in poor health. Overall, researchers cautioned against taking such supplements unless advised by a physician for bone health. Meanwhile, a new Swedish study of dietary, rather than supplemental, calcium intake reports that men with the highest amounts of calcium — nearly double the recommended intake — were 25% less likely to die of all causes. The study of 23,266 men, ages 45 to 79, found the reduced risk among men consuming an average of 1,953 mg of dietary calcium, compared to those with the lowest intake. — Annals of Internal Medicine, American Journal of Epidemiology
…
Read>>
|
February 2010
Men who are feeling blue may not be getting enough folate in their diet, a new Japanese study suggests. Researchers compared blood levels of folate in 530 adults, 313 of them men, with scores for symptoms on a standard test for depression. About 36% of the subjects showed symptoms of depression. But men with the highest folate levels were 50% less likely to have depressive symptoms than those with the lowest levels. On the other hand, higher levels of homocysteine, an amino acid reduced by folate that's been linked to cardiovascular disease and dementia, were linked to greater risk of depression. Neither association was observed in the women. Folate, found in foods such as leafy greens and legumes, and its synthetic form, folic acid, have increasingly been linked to reduced risk of depression. A recent British review of 11 studies came to a similar conclusion, and Tufts researchers reported in 2003 that supplements of folic acid seemed to protect against depressive symptoms. — European Journal of Clinical Nutrition…
Read>>
|
February 2010
Those herbal remedies you're taking for your health may actually interact with your prescription drugs, altering their effectiveness or increasing the risk of bleeding or other cardiovascular problems. A new Mayo Clinic review of nearly 90 studies over the past 44 years warns that patients and physicians may be dangerously unaware of the ways herbal nostrums can interact with common cardiovascular medications. Some herbs, researchers noted, affect the metabolism of medications much as grapefruit juice does. Other popular supplements, including ginkgo biloba, saw palmetto, ginseng and garlic, have their own cardiovascular effects, such as inhibiting platelet aggregation; when combined with common medications such as aspirin or warfarin (Coumadin), this can cause bleeding. Overall, the review identified 27 herbal products that heart patients should be wary of taking. Researchers concluded, "There is a clear need for better public and physician understanding of herbal products through health education, early detection and management of herbal toxicities, scientific scrutiny of their use, and research on their safety and effectiveness." — Journal of the American College of Cardiology
…
Read>>
|
January 2010
The largest study of its kind to date may tip the scales on the controversial question of whether higher vitamin D levels are associated with reduced risk for colorectal cancer. Researchers drawing on data on more than a half-million participants in the European Prospective Investigation into Cancer (EPIC) study concluded that people with more vitamin D were up to 40% less likely to develop colorectal cancer. The study compared the 1,248 EPIC participants diagnosed with colorectal cancer with an equal number of healthy controls. Blood levels of vitamin D below a mid-range were associated with an increased risk of cancer, especially in the colon; high levels didn't confer any extra benefit. The study also found reduced risk associated with high consumption of dietary calcium, but not dietary vitamin D. The EPIC findings are in line with a 2007 meta-analysis of previous studies, but differ from the 2006 Women's Health Initiative, which found calcium and vitamin D supplements had no benefit against colorectal cancer. — British Medical Journal
…
Read>>
|
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
…
Read>>
|
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.
…
Read>>
|
November 2009
In further proof that, at least when it comes to nutrition, it's possible to have too much of a good thing, Norwegian researchers report that high doses of folic acid may increase the risk of cancer. They analyzed long-term results of two clinical trials totaling 6,837 heart patients who were given combinations of folic acid, B12, B6 or placebo to test the lowering of homocysteine, an amino acid in the blood linked to heart disease. Unlike the US, Norway doesn't fortify foods with folic acid, making it ideal for such a study. When participants were revisited after a total of 77 months, those assigned to supplemental folic acid plus B12 were 21% more likely to be diagnosed with cancer and 38% more likely to die of cancer. Lung cancer was the main driver of the results, suggesting a possible connection with subjects' smoking history. Supplementation levels were also quite high: double the US RDA for folic acid and a whopping 167 times the RDA for B12. The bottom line, experts commenting on the findings said, is that it's safest to get your nutrients from food, and that high-dose supplements shouldn't be relied on to prevent chronic disease. — JAMA…
Read>>
|
November 2009
Supplements got a second blow from a new US study linking high blood levels of selenium to increased levels of unhealthy cholesterol. Scientists compared selenium and lipid levels in the blood of 1,042 participants in a national nutrition survey, 48.2% of whom reported taking dietary supplements. Those with the highest selenium levels averaged 8% higher total cholesterol and 10% higher in non-HDL cholesterol (all except the "good" HDL cholesterol). Researchers said the high selenium levels weren't exclusively caused by supplementation, but did raise concerns given the recent popularity of selenium supplements, thought to have antioxidant benefits and possible anti-cancer properties: "We believe that the widespread use of selenium supplements, or of any other strategy that artificially increases selenium status above the level required, is unwarranted at the present time." — Journal of Nutrition
…
Read>>
|
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
…
Read>>
|
July 2009
Maybe you should just chill out and eat some fish. A new Australian study adds to the small but growing body of evidence linking fish-oil consumption with weight management. Analyzing blood levels of the two main omega-3 fatty acids found in fish, EPA and DHA, in 124 subjects of varying weights, researchers found that those at a healthy weight had omega-3 levels nearly 16% higher than obese people. Higher omega-3 levels were associated with a lower BMI, smaller waist measurement and slimmer hip size. People taking fish-oil supplements were excluded from the study, so the omega-3 differences were due solely to dietary intake. While cautioning that the findings don't prove a cause-and-effect connection, scientists noted that animal studies have suggested omega-3s may boost the body's burning of calories to make heat. Omega-3s have also been associated with a greater feeling of "fullness" after a meal.—British Journal of Nutrition…
Read>>
|
July 2009
This week's Alzheimer's conference also produced news about the possible protective effects of omega-3 fatty acids from fish oil. In an 18-month clinical trial of 402 patients already diagnosed with Alzheimer's, supplements of DHA omega-3s failed to slow the progression of the disease. Except for a subgroup with a specific genetic predisposition to Alzheimer's, there was no difference between patients getting DHA and those in a control group. On the other hand, a second study, conducted by a company that markets DHA supplements, did find a benefit in task functioning for healthier individuals with cognitive impairment but who had not yet progressed to Alzheimer's. And a third new study, published in the American Journal of Clinical Nutrition, reported that increased intake of fish, rather than fish-oil pills, was associated with a 20% decrease in the risk of dementia. Those findings relied on data from 14,960 people, age 65 or older, in seven nations; as fish consumption went up, dementia risk went down.…
Read>>
|
July 2009
An apple a day may help keep exercise exhaustion away, according to a small study of the antioxidant quercetin. Found in red apples, berries, cabbage, red onions, broccoli and both green and black tea, quercetin is thought to fight inflammation and promote cell-energy activation, but has mostly been studied in animals. University of South Carolina researchers tested quercetin supplements on a dozen healthy college students in a crossover trial: For seven days, the volunteers drank Tang with 500 mg of added quercetin, twice daily; then for another week the students got Tang without quercetin. Their maximum oxygen uptake and exercise endurance was measured using a stationary bicycle. Compared to the non-quercetin period, participants were able to ride 13% longer when getting the quercetin supplements. Their maximum oxygen uptake also increased slightly, by 4%. Researchers commented that the findings suggest quercetin "may be important in relieving fatigue that keeps people sedentary."—International Journal of Sports Medicine and Exercise Metabolism
…
Read>>
|
July 2009
The US Food and Drug Administration (FDA) has signaled its willingness to allow certain highly qualified health claims that selenium might reduce the risk of prostate, bladder and thyroid cancer. But don't expect supplement makers to rush to splash the FDA-approved language on their labels—the claims aren't exactly a marketer's dream. After summarizing the findings of several "weak studies" on selenium and prostate cancer, for example, the health claim would state, "Based on these studies, FDA concludes that it is highly unlikely that selenium supplements reduce the risk of prostate cancer." Similarly lukewarm—at best—endorsements state that "it is highly uncertain that selenium supplements reduce the risk of bladder cancer in women" or the risk of thyroid cancer. The agency also ruled that there is "no credible evidence" to support even qualified health claims for selenium supplements reducing the risk of other cancers. A spokesperson for a supplements trade group said of the three claims that the FDA would okay, "I can't see why anyone would want to use these claims."—FDA
…
Read>>
|
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
…
Read>>
|
July 2009
Scientists launching the largest clinical trial of its kind hope to find definitive evidence whether vitamin D and omega-3 fatty acids really do help prevent cancer, heart disease and stroke. The five-year study, dubbed VITAL (for VITamin D and OmegA-3 TriaL), will enroll 20,000 men over 60 and women over 65 nationwide. Funded by the National Institutes of Health, the randomized, double-blind, placebo-controlled clinical trial—considered the "gold standard" of medical research—will compare the effects of moderate to high doses of each supplement, both supplements and a placebo. Scientific evidence to date supports a range of possible health benefits for vitamin D as well as for the omega-3s found in fatty, cold-water fish. But most previous vitamin D trials have tested low doses, while omega-3 studies have focused on high-risk populations. Though targeting heart disease and cancer, lead researchers at Brigham and Women's Hospital in Boston said the VITAL trial will also help answer questions about other possible benefits ranging from cognitive function to bone health.—NIH
What do we know so far about vitamin D and your health?
…
Read>>
|
June 2009
Can calcium help you lose weight? Two new studies of this controversial claim suggest that if calcium encourages weight loss at all, it's only calcium from your diet—such as low-fat dairy products—and not from pills. In a two-year randomized controlled trial of 340 participants, National Institutes of Health researchers found no significant difference in changes in body weight or fat between a control group and those taking daily 1,500mg calcium-carbonate supplements. The study subjects were all overweight or obese, and included more women than men. Calcium pills failed to make a difference in a wide range of weight measures, including change in BMI and waist and hip circumference, or in overall health. "Even though there may be other important reasons, such as fracture prevention, to recommend dietary calcium supplementation," researchers concluded, it is unlikely to be effective in controlling weight.
The second study, which analyzed data from 13 previous trials, found that boosting dietary calcium intake by an average of 1,241mg was associated with an increase in fat excretion of 5.2 grams per day. That could have an effect on weight, the Danish researchers noted. But the greater fat excretion was seen only when the analysis zoomed in on dietary calcium intake; when looking at combined dietary and supplemental calcium, the results were mixed. Benefits were greatest for people who began with a low calcium intake, rather than for those adding to an already high calcium level.— Annals of Internal Medicine and Obesity Reviews
…
Read>>
|
June 2009
The experts at the forefront of protecting skin from the sun have recognized one downside to their advice: Practicing "photoprotection" keeps your body from producing natural vitamin D. So the Skin Cancer Foundation has become the first major medical group to call for an increase in the daily recommended intake of vitamin D—from food and supplements—from 400 IU daily to 1,000 IU for adults with limited sun exposure or who practice photoprotection. The chair of the foundation's Photobiology Committee notes that this level "is well within the safety limits set by the US Food and Drug Administration and it may also help alleviate vitamin D deficiency, which has been a growing concern for people." While a few minutes of unprotected sun exposure can make plenty of vitamin D in the skin, the foundation points out that about 90% of non-melanoma skin cancers are associated with UV rays from the sun.—Skin Cancer Foundation
…
Read>>
|
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
…
Read>>
|
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
…
Read>>
|
May 2009
The US Food and Drug Administration (FDA) announced a voluntary recall of 14 diet-aid products sold under the Hydroxycut brand, following reports of liver damage associated with the dietary supplements. The Hydroxycut pills, drinks and powders, manufactured by Iovate Health Sciences, totaled more than 9 million units in sales last year. The FDA received 23 reports of serious health problems linked to Hydroxycut products, including at least one death in 2007 and one customer who required a liver transplant. The FDA didn't learn of the death until March 2009, a delay the agency said is not unusual because reporting is voluntary for supplement makers (unlike prescription drugs, which are closely regulated). Since supplement producers also are not required to give the FDA precise ingredient formulas, the agency said it doesn't know if the liver damage was due to a single ingredient or a combination. Two Iovate products, Hydroxycut Cleanse and Hoodia, are not affected by the recall.—FDA…
Read>>
|
May 2009
Sniffling and wheezing from allergies or asthma? Maybe you're not getting enough folate. New Johns Hopkins research has linked low levels of folate, a type of B vitamin found in leafy green vegetables and (as folic acid) in fortified grain products, to higher risk of allergic symptoms. In a study of 8,083 participants in a national health and nutrition survey, those with the lowest blood folate levels were 40% more likely to wheeze and 31% more likely to have allergenic reactions than those with the highest folate amounts. Researchers wrote, "These findings suggest that dietary folic acid and factors affecting its metabolism might play an important role in the development and perpetuation of allergy and asthma." Low intake of folate and its synthetic form, folic acid, found in supplements and fortified foods, has previously been associated with inflammatory diseases, such as rheumatoid arthritis.—Journal of Allergy & Clinical Immunology…
Read>>
|
April 2009
You could be getting more of a jolt from dietary-supplement pills than you realize. USDA Agricultural Research Service scientists who analyzed 53 dietary supplements found that about half contained the caffeine equivalent of up to two cups of coffee. But supplements aren't required to list caffeine on the label unless they contain added pure caffeine. The stimulant occurs naturally not only in tea and coffee, but also in "botanicals" such as guarana, yerba mate, green tea extract and kola nut. Of the 28 analyzed products that voluntarily listed a caffeine amount on the label, 25 were accurate within 20%. Among all 53 pills, caffeine levels ranged from zero to 800 milligrams per dose (more than in eight cups of coffee).—Agricultural Research…
Read>>
|
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
…
Read>>
|
March 2009
An analysis of 12 previously published clinical trials of vitamin D supplementation confirms that doses of 400 IU or more help reduce bone-fracture risk in older adults. "The anti-fracture benefits of vitamin D have been questioned by several recent trials, leading to uncertainty among patients and physicians," says Dr. Heike A. Bischoff-Ferrari of the University of Zurich, a visiting scientist at Tufts' Bone Metabolism Laboratory. But the combined analysis she and colleagues conducted of trials involving 42,279 participants found that vitamin D supplements decreased the risk of non-vertebral fractures by 14% and of hip fractures by 9%. Doses of vitamin D higher than 400 IU daily were associated with greater risk reductions, 20% and 18% respectively. Among those taking high doses of vitamin D, extra calcium did not have any further protective effect.—Archives of Internal Medicine
…
Read>>
|
March 2009
Men with higher intake of vitamin C from food and supplements appear less likely to develop gout, a painful form of arthritis. Gout is the most common type of inflammatory arthritis in men and is increasingly common. A study of 46,994 men over a 20-year span found that those with the highest total intake of vitamin C (1,500 milligrams daily or more) were 45% less likely to develop gout than those with the lowest intake. Overall, each 500-milligram increase in daily vitamin C was associated with a 17% reduction in gout risk. Vitamin C appears to reduce levels of uric acid in the blood, according to the researchers; a buildup of this naturally occurring compound can form crystal deposits in and around joints, leading to the pain, inflammation and swelling associated with gout.—Archives of Internal Medicine
…
Read>>
|
March 2009
In a study of twentysomething Maine women, daily doses of vitamin D at four times the recommended level were required to maintain optimal blood levels of the "sunshine vitamin" during the winter, when the body can't make as much natural vitamin D. The placebo-controlled study of 112 young women found that daily supplements of 800 International Units (IU) achieved healthy blood levels of vitamin D in 80% of participants. That's quadruple the daily 200 IU recommended for people up to age 50, and more even than the 400 IU recommendation for ages 51 to 70 or the 600 IU for ages 71-plus. The results are important given that current vitamin D recommendations are under review by the Institute of Medicine. Many experts have called for a hike in daily vitamin D guidelines, based on emerging evidence of a wide range of health benefits associated with the vitamin.—Journal of Nutrition
…
Read>>
|
March 2009
Forget vitamin C for fighting the sniffles. The vitamin that actually seems associated with a reduced risk of colds and other upper-respiratory infections is vitamin D. A new study analyzing data on 18,883 participants in a nationwide nutrition survey reports that those with the lowest blood levels of vitamin D were 36% more likely to have recently suffered a cold than those with the highest levels of the "sunshine vitamin." The findings align with recent research suggesting that vitamin D is important to the immune system, along with its well-known role in bone health. Even moderate levels of vitamin D deficiency were linked to increased risk, and those with asthma and COPD were especially affected. Researchers called for clinical trials of vitamin D supplements to confirm the apparent connection.—Archives of Internal Medicine
…
Read>>
|
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…
Read>>
|
February 2009
Calcium might help prevent some cancers, after all. Three years after the Women's Health Initiative (WHI) dashed hopes that calcium and vitamin D supplements might offer a benefit against colorectal cancer, another big study finds an association between calcium intake and reduced risk of colorectal and other digestive-system cancers. One difference: This seven-year study of nearly a half-million participants in the NIH-AARP Diet and Health Study focused on calcium from food, such as low-fat dairy, as well as pills. Women with highest calcium intake were at 23% less risk for digestive-system cancers than those with the lowest intake; for men, the risk-reduction was 16%. Women, but not men, also showed a lower risk of cancer overall with greater calcium consumption.—Archives of Internal Medicine
…
Read>>
|
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
…
Read>>
|
February 2009
Score another one for food versus pills: Orange and blackcurrant juices reduced levels of C-reactive protein (CRP), a marker of inflammation associated with heart disease and diabetes risk, by 11% in a new Danish study, while vitamin E supplements showed no benefit. Researchers compared the juices, vitamin E, a sugar drink and placebo in four different combinations in two 28-day trials on 48 patients with peripheral artery disease. The scientists concluded, "It is the mixture of several agents in fruit and vegetables—here notable fruit juices—that affect the arterial wall; thus patients are better off eating 'whole' fruits and vegetables (juices) than specific supplements."—British Journal of Nutrition
…
Read>>
|
December 2008
Fruits and vegetables can help balance your body's pH and improve bone health, Tufts researchers report. Often overlooked in the emphasis on calcium and vitamin D for strong bones, fruits and vegetables' alkali content can counter the acidic effects of eating protein and grains. Too much acid in the body can increase the excretion of calcium. The Tufts researchers tested 171 older adults for the effects of various supplements on calcium loss. Only potassium bicarbonate—alkaline in its effects, similar to that naturally achieved by eating more vegetables and fruits—significantly reduced calcium excretion.—Journal of Clinical Endocrinology & Metabolism…
Read>>
|
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…
Read>>
|
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
…
Read>>
|
|
|