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to Menu PageThis chapter has demonstrated that the more we learn about the potential influences of dietary factors on health, the more we must realize the need for maintaining an open mind. There are numerous examples where medical consensus--even when it represents the honest opinions of the most knowledgeable, leading scientists in the field--has clearly been wrong. For example, not long ago, the medical community strongly advised pregnant women to avoid taking vitamin supplements. Today pregnant women are advised to do exactly the opposite, especially with regard to taking folic acid to prevent neural tube defects. Another widespread erroneous consensus medical recommendation was the use of margarine rather than butter to reduce risk of coronary heart disease. It now seems, that at least some margarines, which are made from partially hydrogenated vegetable oils, are no better, if not worse, than butter in reducing the risk of heart disease.
Each of these cases was based on limited or no direct evidence. Further, many of the most promising research topics of today, such as the role of dietary antioxidants or alternative ~dietary lifestyles in preventing coronary heart disease and specific cancers, were topics dismissed by most nutritionists only a few years ago as practices of misguided vitamin and food faddists. Given the extreme complexities of the interrelationships between diet and human health and the relatively meager directly relevant data, an element of humility is appropriate in evaluating "alternative" dietary practices. Lack of data, such as from randomized trials, should not be confused with evidence of no benefit. However, a willingness to consider possible benefits of alternative diets does not imply blind acceptance of them, but rather should foster a rigorous scientific evaluation of potentially beneficial practices.
Unfortunately, nutritional therapies or dietary practices that do not readily fit into the "norm" previously have too often been routinely dismissed without such a rigorous examination. An ample investigation of a diet or nutritional intervention should test it in an appropriate model, under the appropriate conditions, and using appropriate research methodologies. In particular, potential study subjects must be selected with extreme care; that is, they should be individuals in which the dietary or nutritional modification, if truly beneficial, is likely to ~produce an effect. Moreover, if a study involves a micronutrient or vitamin or mineral supplementation, the dosage must be optimized to ensure that the intervention will have the opportunity to display an effect. Also, any evaluation of an alternative diet or nutrition research experiment will have to include a recognition that initially negative results do not prove any therapy is valueless; rather, the therapy may merely have been incorrectly tested. Thus, going the extra step is an imperative in conducting this type of research.
Finally, more efforts are needed in translating findings related to specific micro-and macronutrients to whole foods and practical, attractive diets. Only by doing this can physicians and public health officials adequately disseminate important diet and nutrition information to all sectors of the public.