Mediterranean diet and red wine protect against oxidative damage in young volunteers

To assess the effect on oxidative damage of the administration of a Mediterranean diet (MD) compared with an Occidental diet (OD), in young adult volunteers, with or without the concomitant intake of red wine.

Forty-two omnivorous male students 20-27 years old were given either diet for 3 months. During the first and third month they received the prepared diets alone but during the second month they also had 240 ml/day of red wine. Blood and urine samples were taken at 0, 30, 60, and 90 days for analyses. A linear mixed effect model was used to compare the effect of both diets and wine, controlling values by baseline measurements.

MD increased plasma vitamin C, beta-carotene and total antioxidant reactivity (TAR). OD increased plasma vitamin E. Wine supplementation, analyzed combining both diet groups, raised plasma vitamin C, beta-carotene, uric acid, TAR, plasma and urinary polyphenols and decreased plasma vitamin E. Also wine intake increased concentration of red blood cell (RBC) glutathione while significantly decreasing plasma glutathione. In oxidative damage measurements OD group showed higher concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA from peripheral blood leukocytes and plasma nitrotyrosine, when compared with MD group. Wine intake significantly decreased 8-OHdG and plasma nitrotyrosine in both diets, particularly in OD.

Volunteers on MD showed better antioxidant defenses and less oxidative damage than those on OD. Moderate wine consumption improved antioxidant defenses in both groups and counteracted the oxidative damage observed with OD.