Low-GI Diet Linked to Polycystic Ovarian Syndrome

SYDNEY, AustraliaResults from recent study provided evidence to justify the use of low-glycemic index (GI) diets in the management of polycystic ovarian syndrome (PCOS) (Am J Clin Nutr. 2010;92(1):83-92). Women with PCOS are intrinsically insulin resistant and have a high risk of cardiovascular disease (CVD) and type 2 diabetes. Weight loss improves risk factors, but the optimal diet composition is unknown.

Researchers assigned overweight and obese premenopausal women with PCOS (n=96) to consume either an ad libitum low-GI diet or a macronutrient-matched healthy diet, and followed the women for 12 months or until they achieved a 7-percent weight loss. They compared changes in whole-body insulin sensitivity, glucose tolerance, body composition, plasma lipids, reproductive hormones, health-related quality of life and menstrual cycle regularity.

The attrition rate was high in both groups (49 percent). Among completers, ISIOGTT improved more with the low-GI diet than with the conventional healthy diet. There was a significant diet-metformin interaction (P=0.048) with greater improvement in oral-glucose-tolerance test (ISIOGTT) among women prescribed both metformin and the low-GI diet. Compared with women consuming the conventional healthy diet, more women who consumed the low-GI diet showed improved menstrual cyclicity. Among the biochemical measures, only serum fibrinogen concentrations showed significant differences between diets (P<0.05).