CRN questions conclusions of vitamin study

WASHINGTON The Council for Responsible Nutrition on Wednesday countered that a recently-updated meta-analysis in the Cochrane Database of Systematic Reviews that claimed supplementation with vitamins A, E and beta-carotene could be hazardous to your long-term health does not debunk the body of scientific research that has shown that taking antioxidant supplements, including vitamins C and E, beta-carotene, zinc and selenium, consistently over the long-term, can play a role in reducing the risk of chronic disease.

“Antioxidant supplements are certainly not meant to be magic bullets and should not realistically be expected to undo a lifetime of unhealthy habits,” stated Andrew Shao, vice president, scientific and regulatory affairs, for CRN. “However, when used properly, in combination with eating a healthy diet, getting plenty of exercise, not smoking, etc., antioxidant supplements can play an important role in maintaining and promoting overall health.”

The authors of this meta-analysis examined the effects of antioxidant supplements on all-cause mortality, concluding with negative generalizations that discount most of the body of scientific research behind antioxidants supplements.

“The conclusions one can reach from this meta-analysis are very limited,” commented John Hathcock, CRN senior vice president of scientific and international affairs. “In fact, a variation of these results has already been published and was heavily criticized in its original version, due, in part, to the authors’ systematic exclusion of studies that didn’t support the hypothesis they were trying to prove. … With nearly 750 studies to choose from, it’s interesting that they chose to include only 67 studies—less than 9 percent of the total clinical trials on antioxidants that are available. “

Although the authors claimed to be assessing antioxidant supplements for the prevention of mortality, they excluded all studies—405 of them—that reported no deaths, CRN charged.

“It really comes down to whether or not this meta-analysis should mean anything to consumers or scientists,” Shao said. “And from a practical standpoint, it doesn’t mean much.”