Nigella sativa oil affects glucose metabolism and lipid concentrations in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled trial

The aim of the present study was to determine the effects of Nigella sativa (NS) oil on glucose metabolism and lipid concentrations in patients with type 2 diabetes (T2DM). In this double-blind randomized controlled clinical trial, 72 volunteer subjects at Endocrinology Clinics of Kermanshah were recruited. Participants were patients aged 30-60 years old with T2DM. They were randomly divided into intervention (n = 36) and placebo groups (n = 36) and received 3 g/day (one three times a day) NS oil or sunflower soft gel capsules for 12 weeks. At baseline and at the end of the trial, anthropometric indices, dietary intake and biochemical parameters were measured. Sixty-seven patients completed the trial (intervention n = 34, placebo n = 33). Since the data analysis was based on intention-to-treat approach, all 72 subjects (36 in each group) were included for data analysis. Two groups were similar in the baseline characteristics. After the intervention, weight and body mass index decreased in the intervention group compared to the baseline, but it was not significant between the two groups. Dietary intake in both groups changed compared to baseline. Comparison of the two groups indicated that fasting blood sugar, glycated hemoglobin, triglyceride and low density lipoprotein-cholesterol changed significantly in intervention group compared to the placebo group (p < 0.05, adjusted for confounder factors). Insulin level and insulin resistance decreased and high density lipoprotein-cholesterol increased in the intervention group, but after adjusting for confounder factors, they were not significant. Supplementation with NS oil can improve glycemic status and lipid profile in patients with T2DM.