Antioxidants in food and chronic degenerative diseases.

Both preventive and chain breaking antioxidants have a role in the limitation of free radical damage. Some of these may be regarded as "classical", like vitamins E and C but others are more recently discovered, such as the flavonoids, widespread in plant tissues, and the muscle constituents anserine and carnosine. The major conditions in which the role of antioxidants is under intense investigation include coronary artery disease, cancer and diabetes. There are theoretical underpinnings for the efficacy of antioxidants in each of these, with the protection of low density lipoprotein (in respect of the first) being exceptionally persuasive. Much attention is now being focussed on the flavonoids, which are surprisingly pleiotropic in their effects. For one of them, quercetin, over a dozen seemingly independent biological effects can be listed, including the inhibition of low density lipoprotein oxidation. Flavonoids also inhibit peroxidation in foodstuffs, as opposed to tissues. There is much controversy over antioxidant supplementation policies, some authorities recommending a massive programme of supplementation for all ages and classes, others stressing the value of the traditional mixed diet. This matter is unlikely to be resolved soon, but in the meantime sensible supplementation policies should be continued for those most vulnerable, that is, babies and the aged.