A Mediterranean Diet Reduces F2-Isoprostanes and Triglycerides among Older Australian Men and Women after 6 Months

Abstract

Background: Health benefits of a Mediterranean dietary pattern have been shown. However, there are few data on the effects of increased adherence to a Mediterranean diet (MedDiet) in non-Mediterranean countries.Objective: We aimed to determine whether adherence to a MedDiet would result in changes in plasma lipids, glucose and insulin, high-sensitivity C-reactive protein (hs-CRP), and F₂-isoprostanes (F₂-IsoPs) in an Australian population.Methods: The study was a 6-mo parallel, randomized, controlled dietary intervention trial. We recruited 166 participants aged ≥65 y. Participants were stratified on body mass index, sex, and age and assigned to receive either a MedDiet or a habitual diet (HabDiet). The primary outcome was cognitive function, reported elsewhere. As secondary outcomes, assessment of fasting total, LDL, and HDL cholesterol; triglycerides (TGs); glucose; insulin; hs-CRP; and F₂-IsoPs was completed at baseline and at 3 and 6 mo. The MedDiet group followed a prescribed diet containing 15-45 mL extra-virgin olive oil/d, abundant vegetables, fruit, nuts, legumes, and whole grains, as well as moderate fish, poultry, and dairy foods. Dietary intake was measured by 3-d weighed food records at baseline and at 2 and 4 mo. Results were analyzed by using linear mixed-effects models.Results: Compared with the HabDiet, the MedDiet resulted in lower TGs at 3 mo (mean difference: -0.15 mmol/L; 95% CI: -0.23, -0.07 mmol/L; P < 0.001) and 6 mo (mean difference: -0.09 mmol/L; 95% CI: -0.18, -0.01 mmol/L; P = 0.03) and lower F₂-IsoPs at 3 mo (mean difference: -103.5 pmol/L; 95% CI: -154.2, -52.7 pmol/L; P < 0.001) and 6 mo (-65.4 pmol/L; 95% CI: -117.1, -13.7 pmol/L; P < 0.001). Lipoprotein, glucose and insulin, and hs-CRP concentrations were not significantly different between groups.Conclusion: A high adherence to a MedDiet for 6 mo resulted in a significant reduction in TGs and F₂-IsoPs among older Australians. This trial was registered at clinicaltrials.gov as ACTRN12613000602729.

Keywords: F2-isoprostanes; Mediterranean diet; cardiovascular risk factors; older Australians; oxidative stress.