Food and nutrient exposures: what to consider when evaluating epidemiologic evidence

Nutritional epidemiology is the science concerned with conducting research into the relation between diet and disease risk. The public has a great deal of interest in this issue. Much of that interest, however, is fueled by the publication of sensationalized, startling, and often contradictory health messages. Unfortunately, there is a great deal of confusion in both the scientific press and the public or lay press about the nature of nutritional epidemiology, its strengths, and its limitations. The purpose of this article is to discuss these strengths and limitations. It is hoped that clarification of these issues can help lead to a resolution of the research community's and lay public's misunderstandings about nutritional epidemiology research.