A 3 years follow-up of a Mediterranean diet rich in virgin olive oil is associated with high plasma antioxidant capacity and reduced body weight gain

Background/Objectives: The aim of this study was to analyze the influence of a Mediterranean dietary pattern on plasma total antioxidant capacity (TAC) after 3 years of intervention and the associations with adiposity indexes in a randomized dietary trial (PREDIMED trial) with high cardiovascular risk patients. Subjects/Methods: 187 subjects were randomly selected from the PREDIMED-UNAV center after they completed 3-year intervention program. Participants were following a Mediterranean-style diet with high intake of virgin olive oil or high intake of nuts, or a conventional low-fat diet. Adiposity indexes were measured at baseline and at year 3. Plasma TAC was evaluated using a commercially available colorimetric assay kit. Results: Plasma TAC in the control, olive oil and nuts groups was 2.01 +/- 0.15, 3.51 +/- 0.14 and 3.02 +/- 0.14 mM Trolox, respectively after adjusting for age and sex. The differences between the Mediterranean diet and control groups were statistically significant (P < 0.001). Moreover higher levels of TAC were significantly associated with a reduction in body weight after 3 years of intervention among subjects allocated to the virgin olive oil group (B = -1.306; 95% CI = -2.439 to -0.173; P = 0.025, after adjusting for age, sex and baseline body mass index). Conclusions: Mediterranean diet, especially rich in virgin olive oil, is associated with higher levels of plasma antioxidant capacity. Plasma TAC is related to a reduction in body weight after 3 years of intervention in a high cardiovascular risk population with a Mediterranean-style diet rich in virgin olive oil. European Journal of Clinical Nutrition (2009) 63, 1387-1393; doi:10.1038/ejcn.2009.106; published online 26 August 2009