A Mediterranean Low-Glycemic-Load Diet alone or in Combination with a Medical Food Improves Insulin Sensitivity and Reduces Inflammation in Women with Metabolic Syndrome

Abstract

Aim: To determine the effects of a Mediterranean-style low-glycemic load diet alone or in combination with a medical food (MF) on insulin resistance and inflammation in women with metabolic syndrome (MetS). Study design: Two groups, Parallel study with control. Place and Duration of Study: Department of Nutritional Sciences, University of Connecticut, Storrs, CT; Department of Emergency Medicine, University of Florida, Jacksonville, FL; Department of Medicine, University of California, Irvine, CA. The study was carried out from September of 2009 to May 2010. Methodology: Eighty three women (20-75 y) with MetS. Participants were randomly allocated to consume diet alone (control group) or the diet plus the MF (MF group) for 12 wk. Body composition was measured at baseline, week 8 and week 12 by use of bioelectrical impedance in all participants while Dual-emission X-ray absorptiometry was used for 37 of the subjects. Insulin resistance, plasma insulin, leptin, adiponectin and the inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin-6 (IL-6), adhesion molecules, sICAM-1 and sVCAM-1, were measured at the same time points. Results: Independent of group allocation, women had decreases in body mass index (p < 0.0001) and body and trunk fat (p < 0.0001). Plasma insulin, insulin resistance, and leptin were also significantly decreased over time (p < 0.0001), while plasma adiponectin levels did not change. Regarding inflammatory markers, significant reductions were found in TNF-α (p < 0.0001) and sICAM-1 levels (p < 0.001), but not in IL-6 or sVCAM-1. At 12 wk, sICAM was reduced only in the MF group (p<0.05 vs control). Conclusion: A Mediterranean-style diet, in combination with a MF, are a viable option to decrease factors associated with increased risk for type 2 diabetes and coronary heart disease.