Functional foods: Their role in health promotion and disease prevention

The effect of food factors on health status has been recognized since antiquity. More recently, epidemiological studies have led to fundamental research for unraveling the chemistry and mechanism of action of dietary phytochemicals and bioactives. Functional foods and natural health products encompass a wide range of food and ingredients, with a variety of bioactives responsible for their efficacy in health promotion and disease prevention. Phenolic and polyphenolic compounds constitute an important class of secondary plant metabolites that act as free radical scavengers and inhibitors of LDL cholesterol oxidation and DNA breakage, among others. Thus, the role of food phenolics and polyphenolics in the prevention of cardiovascular disease and certain types of cancer is well recognized. In addition, certain marine foods have often been considered as "heart food" because of their omega-3 constituents which are known to lower blood triacylglycerol and, possibly, cholesterol levels. Thus, food factors from both plants and animals may be participating in human health promotion.