THE EFFECTS OF NIGELLA SATIVA OIL WITH A BALANCED LOW-CALORIE DIET ON INSULIN RESISTANCE IN OBESE WOMEN: GENE-INTERVENTION INTERACTIONS

Abstract

The aim of the present study was to evaluate the effects of Nigella sativa (NS) oil with calorie restriction on insulin resistance with regard to adiponectin and peroxisome proliferator-activated receptor gamma-2 (PPAR-gamma 2) gene polymorphisms in obese women. In this double-blind placebo-controlled randomized clinical trial, 100 volunteer obese women were recruited. Participants were randomly divided into an intervention and a placebo group. Each group received a low-calorie diet either with NS oil or placebo for 8 weeks. Pro/Pro, Pro/Ala, T7; TG and GG genotypes were found in 77 23, 72, 24 and 4%, of the women, respectively. Comparison between the two groups indicated that body weight decreased signOcantly in the NS group compared to the placebo group independent of the genotypes (-5.1 vs.-2.9 kg; p<0.01). There were significant differences in changes of insulin concentrations (-5.7 vs.-1.7 mu U/mL; p<0.01) and insulin resistance (HOMA: -1.4 vs.-0.4; p<0.01) in participants with the Pro/Ala vs. Pro/Pro polymorphism in the NS group. In combination with calorie restriction, NS oil decreased weight, independent of the genotypes, but its lowering effect on insulin concentrations and insulin resistance was influenced by the Pro/Ala genotype. More studies are needed to elucidate gene/ intervention interactions on obesity phenotype.