Wednesday, July 20, 2005

Essential nutrients: food or supplements?

Alice Lichtenstein and Robert Russell offer a remarkable essay on food and dietary supplements in the latest issue of the Journal of the American Medical Association (JAMA). The authors, colleagues on the faculty of Tufts' Friedman School of Nutrition Science and Policy, cast doubt on the value of dietary supplements and emphasize the health advantages of a wholesome diet based on real foods.
The consumption of adequate levels and proper balance of essential nutrients is critical for maintaining health. The identification, isolation, and purification of nutrients in the early 20th century raised the possibility that optimal health outcomes could be realized through nutrient supplementation. Recent attempts using this approach for cardiovascular disease and lung cancer have been disappointing, as demonstrated with vitamin E and beta carotene. Moreover, previously unrecognized risks caused by nutrient toxicity and nutrient interactions have surfaced during intervention studies. The most promising data in the area of nutrition and positive health outcomes relate to dietary patterns, not nutrient supplements. These data suggest that other factors in food or the relative presence of some foods and the absence of other foods are more important than the level of individual nutrients consumed. Finally, unknown are the implications on public health behavior of shifting the emphasis away from food toward nutrient supplements. Notwithstanding the justification for targeting recommendations for nutrient supplements to certain segments of the population (eg, the elderly), there are insufficient data to justify an alteration in public health policy from one that emphasizes food and diet to one that emphasizes nutrient supplements.
Lichtenstein and colleague Miriam Nelson have recently completed the latest book in Nelson's "Strong Women" series: Strong Women, Strong Hearts.

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