Adherence to a Mediterranean diet and plasma concentrations of lipid peroxidation in premenopausal women

Background: A Mediterranean diet has been associated with a reduced risk of cardiovascular disease and mortality. A possible mechanism is through a decrease in lipid peroxidation (LPO); however, evidence linking the Mediterranean diet with lower LPO in premenopausal women is sparse. Objective: We investigated whether adherence to a Mediterranean diet was associated with lower LPO concentrations in premenopausal women. Design: Two hundred fifty-nine healthy women aged 18-44 y were followed for ≤2 menstrual cycles. Plasma concentrations of F₂-isoprostane (8-iso-PGF2α), 9-hydroxyoctadecadieneoic acid (9-HODE), and thiobarbituric acid reactive substances (TBARS) were measured ≤8 times per cycle at visits scheduled by using fertility monitors. Diet was assessed ≤4 times per cycle by using 24-h dietary recalls. The alternate Mediterranean Diet Score (aMED) (range: 0-9) was calculated on the basis of intake of vegetables, legumes, fruit, nuts, whole grains, red and processed meat, fish, and alcohol and the ratio of monounsaturated to saturated fat. Results: A 1-unit increase in aMED was associated with a 4.50% decrease in 8-iso-PGF2α concentrations (95% CI: -6.32%, 22.65%) and a 14.01% decrease in 9-HODE concentrations (95% CI: -17.88%, -9.96%) after adjustment for energy intake, age, race, body mass index, plasma ascorbic acid, and serum cholesterol. No significant association was observed between aMED and TBARS. A 1-unit increase in aMED was associated with a 1.39% increase (95% CI: 0.07%, 2.72%) in plasma ascorbic acid concentrations. Conclusions: Adherence to a Mediterranean diet is associated with lower LPO and higher ascorbic acid concentrations. These results confirm that decreased LPO is a plausible mechanism linking a Mediterranean diet to reduced cardiovascular disease risk.