Adherence to the Mediterranean diet is associated with total antioxidant capacity in healthy adults: the ATTICA study

Background: Greater adherence to the Mediterranean diet has been associated with a lower incidence of cardiovascular disease and cancer. Objective: We studied the effect of the Mediterranean diet on total antioxidant capacity (TAC) in 3042 participants who had no clinical evidence of cardiovascular disease. Design: During 2001-2002, a random sample of 1514 men and 1528 women aged 18 - 89 y from the Attica area of Greece was selected. TAC was measured with an immune-diagnostic assay. Food consumption was evaluated with a validated food-frequency questionnaire, and adherence to the Mediterranean diet was assessed on the basis of a diet score that incorporated the inherent characteristics of this diet. Results: TAC was positively correlated with diet score. The participants in the highest tertile of the diet score had, on average, 11% higher TAC levels than did the participants in the lowest tertile, even after adjustment for relevant confounders (P < 0.01). On the other hand, the participants in the highest tertile of the diet score had, on average, 19% lower oxidized LDL-cholesterol concentrations than did the participants in the lowest tertile (P < 0.01). An additional analysis showed that TAC was positively correlated with the consumption of olive oil (p = 0.54, P = 0.002) and of fruit and vegetables (p = 0.34 and p = 0.31, respectively; P < 0.001 for both), whereas it was inversely associated with the consumption of red meat (p = -0.35, P = 0.02). Conclusion: Greater adherence to the Mediterranean diet is associated with elevated TAC levels and low oxidized LDL-cholesterol concentrations, which may explain the beneficial role of this diet on the cardiovascular system.