Are clinical trials are the most reliable tool for evaluating the benefits of specific nutrients or dietary habits?
A. Not necessarily. Clinical trials are a valuable and reliable tool for assessing the effectiveness of pharmaceutical products (drugs). The drug can be given to one group of patients and not to another group, and the difference in response can be observed. The patients are not already being exposed to the drug from their diet or any other sources. They are getting it in the study or they are not getting it at all. Studying nutrients, both in nutritional supplements and food, is different. People are likely already getting these nutrients from their regular diets, and if participating in a nutritional study should not be asked to eliminate these foods so it becomes very difficult to evaluate the effects of the added amounts. Additionally, the benefits of specific nutrients or dietary patterns are related to disease prevention, not disease treatment. Such benefits may take years to develop, much longer than most clinical trials. Finally, most clinical trials are conducted in people who
