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
Jennifer L. Jones
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Daniela Ackermann
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Jacqueline Barona
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Mariana Calle
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Catherine Andersen
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Jung Eun Kim
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Jeff S. Volek
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
Mark McIntosh
Departmemt of Emergency Medicine, University of Florida, Jacksonville, Florida, USA.
Wadie Najm
Department of Medicine, University of California, Irvine, California, USA.
Robert H. Lerman
Metagenics Inc., Gig Harbor, WA, USA.
Maria Luz Fernandez *
Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut, USA.
*Author to whom correspondence should be addressed.
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.
Keywords: Metabolic syndrome, mediterranean diet, glycemic load, insulin, inflammation, body composition