Functional foods and health promotion.

Statements about the ability of selected foods to reduce the risk of diseases and to enhance the quality of life continue to captivate, and at times polarize, opinions. Interests in these "functional" foods and their active components are being propelled by increasing health care cost, recent legislative events and mounting scientific evidence. Increasingly, scientists are being asked to clarify the precise role that foods have in maintaining and promoting health. Accepting this movement as an opportunity to "optimize nutrition" rather than as a way in which to endorse good or bad foods or as a marketing gimmick will surely make it more acceptable to many scientists. However, the response to functional foods depends on several factors, including genetics, physiologic state and the composition of the entire diet. Although evaluation of the benefits or risks of foods normally does not entail the same extensive examination as that required of drugs, this does not negate the need for sound scientific information for making recommendations to the consumer. Identification of sensitive and reliable biomarkers will be key to adequate assessment of the true effect of foods and their components. Inulin and oligofructose are components of the diet that deserve added attention for their potential health benefits. Evidence that oligofructose and inulin alter several biomarkers, including gastrointestinal transit time, experimentally induced neoplasia and colonic microflora, suggests that these nondigestible carbohydrates are naturally occurring dietary constituents that may improve the quality of life and increase disease resistance in both humans and animals.