Nutrition and health promotion: role of phytochemicals and functional foods

The diminished cellular efficiency in energy production is the molecular mechanism underlying the physiopathological processes of ageing and of the related dysmetabolic pathologies. This reduction in energy production (ATP) is due both to functional and structural alterations of the tissues and to damage to the blood vessels and their reduced efficiency in supplying oxygen and nutrients to the organs. The deficiency of ATP causes a reduction in the bioavailability of all the molecules whose biosynthesis requires the intervention of ATP itself. Therefore, one must expect a reduction of the ex-novo biosynthesis of proteins, nucleic acids and phospho- and glyco-lipids. The diminished efficiency of the cell in the synthesis of these compounds causes a slowing of the repair processes and replacement of the various lipid or glycoprotein molecules, which make up the bilayer structural organization of the cell membrane. This leads to progressive structural alteration of membrane, manifested by a progressive reduction of membrane fluidity. The consequence is the cause of secondary metabolic damage to the cells. All this results in reduced capacity of the proteins to collided with the ligands with which they must interact in order to carry out their own functional and biological roles, such as proteins interacting with their own specific substrate. There is thus a spiral of structural and functional damage to cells and tissues, starting with the reduced efficiency in ATP synthesis which is further amplified by the decreased rate of synthesis of membrane macromolecules and lipids, the increase in intracellular calcium and potassium, and the increase in peroxidation processes. How the onset of this spiral could be kept under control with either an adequate diet or supplying of functional foods will be the main argument of this presentation.