[Nutritional support, free radicals, and antioxidants]

Antioxidants and free radical scavengers are molecules endowed with the ability of neutralizing reactive oxygen species that may accumulate in the organism during various pathologic processes. In circumstances of peroxidation of lipids and damage to enzymatic chains, cell membranes and other structures may be followed by functional losses and even cell death. Many antioxidants are normal constituents of the diet in the form of vitamins, trace elements and amino acids, and other useful properties cannot be easily distinguished from their free-radical scavenging abilities. Much controversy surrounds also the indications of these substances, both for prophylactic and therapeutic purposes. The first large-scale population studies have only recently been arranged, and additional investigations are required in many promising areas, including cancer patients undergoing chemo and radiotherapy.