Wine phenolics: contribution to dietary intake and bioavailability

Current research suggests that wine contains substances that may reduce the mortality rate from coronary heart diseases. The oxidation of low-density liporoteins (LDL) is thought to be a key step in the development of atherosclerosis. In previous research, catechin oligomers, procyanidin dimers and trimers were extracted, isolated and purified from grapes seeds and tested for their inhibition on LDL oxidation, along and with other monomeric wine phenolics. We quantify the level of phenolics, major catechins [(+)-catechin, (-)-epicatechin, procyanidin dimers B1, B2, B3, B4], phenolics acids, caftaric acid and malvidine-3-glucoside by HPLC with UV detection for 60 French varietal commercial wines taken from the South of France in order to appreciate the daily dietary intake of these compounds for French population. Based on a still significant French red wine consumption of 180 ml/day, the current daily intake of phenolics can be estimated at 400.2 mg/day/resident and catechins (monomers, dimers B-1, B-2, B-3, B-4) at 83.2 mg/day/resident, including 40% of monomers for the French population. Red wine, and particularly Egiodola, and Cabernet-Sauvignon varieties, contributes to a very significant proportion of phenolics dietary intake and, in particular catechins. These results provide a basis for epidemiological evaluation of phenolics and catechins intake by wine consumption in the French population. Few data exist on absorption and metabolism of phenolics from wine. Further studies are necessary to determine the behaviour of this class of compounds in vivo after wine absorption. (C) 2000 Elsevier Science Ltd. All rights reserved.