M. Barbaste, S. Vergé, M. Dumas, S. Soulet, B. Nay, V. Arnaudinaud, J.-Cl. Delaunay, C. Castagnino, C. Chèze, J. Vercauteren

GESNIT (Groupe d'Etude des Substances Naturelles à Intérêt Thérapeutique) "EA 491*, Laboratoire de Pharmacognosie, Faculté de Pharmacie, Université Victor Segalen Bordeaux 2, 146, rue Léo Saignat, 33076 Bordeaux, France. Phone: 33 (5) 57 57 12 59, Fax: 33 (5) 56 96 09 75 - Email : joseph.vercauteren@gnosie.u-bordeaux2.fr
* With the financial support of MENRT and Conseil Régional d'Aquitaine which are warmly acknowledged.

Most of the many epidemiological studies in the field strongly suggest that an equilibrated diet such as the so-called "mediterranean diet", is associated with protective effects against major diseases, and particularly, against cardiovascular risks. Since many reports also consider "reactive oxygen species" or "free radical oxidations" to be responsible for the accompanying disorders of most pathologies as well as for ageing, it is conceivable that natural plant metabolites such as polyphenols, are likely to play an important role in insuring this protection. Indeed, not only their presence, in particularly high amounts and varieties in foods of such a diet, but also, inter alia, their very potent antioxidant or radical scavenging properties, make polyphenols best accounting for the parodoxical part of the "french paradox". Therefore, many efforts have been made to assess the mechanisms for such a cardiovascular disease protection. Whatever convincing were the polyphenols properties demonstrated by many in vitro experiments to support those theories, quite a great number of the results appeared somewhat contradictory when transposed to humans, in the in vivo situation. Some people totally refute this explanation, thinking that health benefits, as far as alcoholic beverages are concerned, originate from ethanol but also, with no doubt, some polyphenols even revealing to be "pro-oxidants".

Keywords: Nutrition, elderly, reactive oxygen species, polyphenols, dietary antioxidants, radical scavenging properties, mechanisms and paradoxical issues, cardioprotective effects, french paradox, aging.