New JAMA Study Raises Issue of How Nutrients Should Be ...( WASHINGTON Dec. 4 -- A study pub...),Health

WASHINGTON, Dec. 4 /PRNewswire-USNewswire/ -- A study published in the December 5 issue of the Journal of the American Medical Association (JAMA) (See Note 1) raises important philosophical issues with regard to researching the effects of nutrients in humans and demonstrates the confusion that persists when new research contradicts earlier research.

According to Andrew Shao, Ph.D., vice president, scientific and regulatory affairs, Council for Responsible Nutrition, "The problem that we have for the scientific community in evaluating the effects of nutrients in people is that everyone from scientists to journalists to consumers -- wants conclusive answers, consequently we're always looking at what the 'study du jour' tells us and trying to make it answer all questions. But the reality is that science doesn't always move forward -- there is some back and forth -- and while research may seem to contradict itself, that should not be interpreted to mean one type of study trumps another, particularly when different studies ask and answer different questions. Seemingly conflicting data can exist side by side, when one understands that not all studies are asking the same questions in the same populations."

The JAMA review set out to evaluate the change over time in the quantity and content of citations for two highly cited observational studies that found major cardiovascular benefits associated with vitamin E supplementation and to understand how these benefits continue to be defended in literature, despite contradicting evidence from large RCTs. In order to make the findings more generalized, the study also examined the citations for observational studies showing the protective effects of beta-carotene on cancer and estrogen on Alzheimer's disease. The study authors conclude that there is "an apparent split of stance in the scientific literature" when it comes to these substances.

The researchers gathered and reviewed 172 articles on vit
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