Natural Foods Merchandiser

Recent supplement science a mixed bag

The confusing world of science continued to be, well, confusing in December and January. The U.S. Food and Drug Administration proposed changes for the calcium health claim, folate levels saw mixed research results and vitamin E took another hit.

On Jan. 5, the FDA proposed new claims for foods and dietary supplements containing calcium and vitamin D and their ability to reduce the risk of osteoporosis. The proposed changes would add a claim linking the use of calcium and vitamin D together with a reduced risk of osteoporosis, and would shorten claim language by "dropping the reference to sex, race and age since the benefits apply to both sexes at all ages and race categories; dropping the need to identify the mechanism by which calcium reduces the risk of osteoporosis; dropping the requirement that the claim state that there are limits to benefit of calcium intakes above 200 percent of the daily value."

As for folate, one study has found that it might decrease the risk of Alzheimer's disease, but another found that B vitamin supplementation, including vitamins B6, B12 and folic acid (the synthetic form of folate), had no effect on cognitive functioning.

In a study published in the January issue of the Archives of Neurology, researchers gave food questionnaires to 965 people 65 years or older without dementia. Based on the answers, researchers calculated total dietary and supplement intake of folate and vitamins B6 and B12 for each participant.

"Higher intake of folate and vitamins B6 (pyridoxine hydro?chloride) and B12 (cyanocobalamin) may decrease the risk of Alzheimer's disease through the lowering of homocysteine levels," researchers wrote.

However, a study in the January issue of Archives of Internal Medicine disagreed. Researchers reviewed 14 trials and found that in all but a very few, B vitamin supplementation had no effect on cognitive function. The researchers concluded that results do not yet "provide adequate evidence of an effect of vitamin B6 or B12 or folic acid supplementation, alone or in combination, on cognitive function testing in people with either normal or impaired cognitive function."

In other folate news, the Journal of the American Medical Association published a study on folic acid and cardiovascular disease in December 2006. Data from 16,958 participants with pre-existing vascular disease were analyzed from 12 randomized controlled trials that compared folic acid supplementation with either placebo or usual care for CVD.

"Folic acid supplementation has not been shown to reduce risk of cardiovascular diseases or all-cause mortality among participants with prior history of vascular disease. Several ongoing trials with large sample sizes might provide a definitive answer to this important clinical and public health question," researchers wrote.

Vitamin E was the subject of another study regarding cognitive impairment—and it didn't fare well. The sub-study to the Harvard's Women's Health Study, including 6,377 women 65 years or older, looked at three cognitive assessments—general cognition, verbal memory and category fluency. In an article in the December 2006 Archives of Internal Medicine, researchers proposed that oxidative stress might play a role in cognitive decline and thus, vitamin E, an antioxidant, might provide some benefits. However, researchers concluded, "Long-term use of vitamin E supplements did not provide cognitive benefits among generally healthy older women."

Natural Foods Merchandiser volume XXVIII/number 2/p. 11

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