Effect of a Traditional Mediterranean Diet on Lipoprotein Oxidation

Abstract

Background: Despite the richness in antioxidants of the Mediterranean diet, to our knowledge, no randomized controlled trials have assessed its effect on in vivo lipoprotein oxidation. Methods: A total of 372 subjects at high cardiovascular risk (210 women and 162 men; age range, 55-80 years), who were recruited into a large, multicenter, randomized, controlled, parallel-group clinical trial (the Prevenció n con Dieta Mediterránea [PREDIMED] Study) directed at testing the efficacy of the traditional Mediterranean diet (TMD) on the primary prevention of coronary heart disease, were assigned to a low-fat diet (n = 121) or one of 2 TMDs (TMDϩvirgin olive oil or TMDϩnuts). The TMD participants received nutritional education and either free virgin olive oil for all the family (1 L/wk) or free nuts (30 g/d). Diets were ad libitum. Changes in oxidative stress markers were evaluated at 3 months. Results: After the 3-month interventions, mean (95% confidence intervals) oxidized low-density lipoprotein (LDL) levels decreased in the TMD ϩ virgin olive oil (−10.6 U/L [−14.2 to −6.1]) and TMDϩnuts (−7.3 U/L [−11.2 to −3.3]) groups, without changes in the low-fat diet group (−2.9 U/L [−7.3 to 1.5]). Change in oxidized LDL levels in the TMDϩ virgin olive oil group reached significance vs that of the low-fat group (P =.02). Malondialdehyde changes in mononuclear cells paralleled those of oxidized LDL. No changes in serum glutathione peroxidase activity were observed.

Health Benefits of Nut Consumption

“…In a recent parallel feeding trial with higher statistical power than usual clinical studies with nuts, the PREDIMED study [106], a Mediterranean diet enriched with 30 g mixed nuts (half of it walnuts, the rest almonds and hazelnuts) given daily for 12 weeks to subjects at high cardiovascular risk resulted in a lower oxidized LDL level compared with the control diet. Conversely, a smaller study using the same mixed-nut diet against a similar healthy diet without nuts for 12 weeks in patients with metabolic syndrome failed to show any between-diet differences in oxidized LDL and other oxidation biomarkers, except for reduced DNA damage with the nut diet [107].…”

Mediterranean diet supplemented with coenzyme Q10 induces postprandial changes in p53 in response to oxidative DNA damage in elderly subjects

“…The postprandial oxidant stress acutely triggers atherogenic changes, including increases in lowdensity lipoprotein (LDL) oxidation, sympathetic tone, vasoconstriction, and thrombogenicity. The Mediterranean diet (Med diet), which is rich in minimally processed natural foods, has been associated with improved cardiovascular health and longevity (Lichtenstein et al 2006;Fito et al 2007). Specifically, diets that include large amounts of fresh unprocessed plants, with moderate levels of lean protein and beneficial fats (such as omega-3 and monounsaturated fats) and that are rich in antioxidants substantially improve postprandial dysmetabolism (Lichtenstein et al 2006;Jimenez-Gomez et al 2010).…”

Diet quality of a population sample from coastal north-east Spain evaluated by a Mediterranean adaptation of the Diet Quality Index (DQI)

“…The Mediterranean diet (MD) is an eating pattern characterized by a lifestyle and culture that has been reported to contribute to better health and quality of life for those who adhere to it (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) . Among its advantages, recent findings from large cohort studies suggest that a high degree of adherence to the MD is associated with a significant reduction in mortality (11)(12)(13) .…”