Phenols in the plant and in man. The potential for possible nutritional enhancement of the diet by modifying the phenols content or profile

There is growing recognition that many phenolic secondary metabolites prese nt in foodstuffs may possibly exert beneficial effects on human health. Thi s may to some degree be mediated via antioxidant actions, but a range of mo re specific pharmacological effects have also been proposed. Given this bac kground, there may be favourable consequences for the general health of Wes tern populations as a result of optimising the phenolic content of the diet . This paper reviews what is known of the function of phenolics both in the plant and in man. It also describes current understanding of the biosynthe sis of phenolics in plants, with emphasis on where potential controlling st eps may exist. Finally, advances in identification and isolation of the gen es coding for phenolic biosynthetic enzymes or regulatory proteins are also summarised. Taken together, this information provides a basis for attempts to modify and optimise the phenolic content of food crops, using either co nventional plant breeding along with manipulation of agronomic practices, o r else the more targeted approaches of modern molecular biology. (C) 2000 S ociety of Chemical Industry.