Close adherence to a Mediterranean diet improves endothelial function in subjects with abdominal obesity

Background: Abdominal obesity (AO) is associated with increased risk of cardiovascular disease and type 2 diabetes, whereas the Mediterranean diet exerts a cardioprotective effect. Objective: We examined whether a close adherence to a Mediterranean-style diet improves endothelial function in individuals with AO. Design: We recruited 90 subjects with AO without cardiovascular disease or type 2 diabetes. Participants were randomly assigned to the intervention or control group. Both groups were instructed to follow a Mediterranean-style diet for 2 mo. Subjects in the intervention group additionally had to follow a specific relevant daily and weekly food plan with close supervision by a dietitian and provision of basic foods. Flow-mediated dilatation (FMD), lipids, C-reactive protein (CRP), and insulin resistance with the homeostasis model assessment (HOMA-IR) were measured. Results: After 2 mo, subjects in the intervention group increased their intake of total fat due to higher consumption of monounsaturated fatty acids as well as intakes of dietary fiber, vitamin C, and alcohol compared with the control group (all P < 0.05). The intervention group also increased FMD (2.05%; 95% CI: 0.97, 3.13%), whereas no effect was found in the control group (-0.32%; 95% CI: -1.31, 0.67%). Changes in lipids and CRP concentrations did not differ between the 2 groups, whereas diastolic blood pressure decreased in the intervention group (-6.44 mm Hg; 95% CI: -8.57, -4.31 mm Hg) compared with the control group (-0.76 mm Hg; 95% CI: -2.83, 1.31 mm Hg). Finally, there was a trend for a reduction in HOMA-IR in the intervention group compared with the control group (P = 0.072). Conclusion: Close adherence to a Mediterranean-style diet achieved by close dietetic supervision improves endothelial function in subjects with AO. Am J Clin Nutr 2009;90:263-8.