Effects of royal jelly supplementation on glycemic control and oxidative stress factors in type 2 diabetic female: A randomized clinical trial

It has been proposed that royal jelly has antioxidant properties and may improve oxidative stress and glycemic control. Therefore, we investigated the effects of royal jelly supplementation in diabetic females. In this pilot, parallel design randomized clinical trial, 50 female volunteers with type 2 diabetes were randomly allocated to the supplemented (25, cases) and placebo (25, cases) groups, based on random block procedure produced by Random Allocation Software, given a daily dose of 1,000 mg royal jelly soft gel or placebo, respectively, for 8 weeks. Before and after intervention, glycemic control indices, antioxidant and oxidative stress factors were measured. After royal jelly supplementation, the mean fasting blood glucose decreased remarkably (163.05 +/- 42.51 mg/dL vs. 149.68 +/- 42.7 mg/dL). Royal jelly supplementation resulted in significant reduction in the mean serum glycosylated hemoglobin levels (8.67%+/- 2.24% vs. 7.05%+/- 1.45%, P=0.001) and significant elevation in the mean insulin concentration (70.28 +/- 29.16 pmol/L vs. 86.46 +/- 27.50 pmol/L, P=0.01). Supplementation significantly increased erythrocyte superoxidase dismutase and glutathione peroxidase activities and decreased malondialdehyde levels (P < 0.05). At the end of study, the mean total antioxidant capacity elevated insignificantly in both groups. On the basis of our findings, it seems that royal jelly supplementation may be beneficial in controlling diabetes outcomes. Further studies with larger sample size are warranted.