Curcumin and zinc co-supplementation along with a loss-weight diet can improve lipid profiles in subjects with prediabetes: a multi-arm, parallel-group, randomized, double-blind placebo-controlled phase 2 clinical trial

BACKGROUND: Diabetes is one of the major public health concerns. Prediabetes can increase the risk of developing some non-communicable diseases such as type 2 diabetes. Given the increasing trend of prediabetes, it is critical to control it and prevent its complications. Curcumin is a major bioactive component of turmeric. Zinc is an antioxidant nutrient. The present trial aimed to evaluate the effect of curcumin and zinc co-supplementation along with a loss-weight diet on serum lipid profiles in overweight or obese patients with prediabetes. METHODS: Eighty-four participants were randomized to four groups (curcumin (500 mg/day), zinc (30 mg/day), “curcumin and zinc”, and placebo) for 90 days. Serum total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), non-HDL, HDL/LDL ratio, weight, BMI, waist circumstance (WC), hip circumstance (HC), physical activity (PA) and dietary intake were determined pre and post-intervention. This study will be conducted at Yazd Diabetes Research Clinic, Shahid Sadoughi University of Medical Sciences. RESULTS: Totally, 82 participants were included in the final analysis. After the adjusted PA effect, changes in serum TG (adjusted p = 0.001), LDL (adjusted p = 0.035), non-HDL (adjusted p = 0.003), HDL/LDL ratio (adjusted p = 0.002), and HDL (adjusted p < 0.0001) revealed a significant difference between the groups. However, the changes in weight (adjusted p = 0.004) and BMI (adjusted p = 0.006) were significant but the changes in dietary intake, PA, WC, and HC were non-significant (adjusted p ≥ 0.05). Despite that there was a significant difference for post-intervention HDL levels (adjusted p = 0.016), other lipid profiles showed no significant difference (adjusted p ≥ 0.05). CONCLUSION: The beneficial effects of “curcumin and zinc” co-supplementation was reported for the changes of some lipid profiles (TG, LDL, HDL, non-HDL, and HDL to LDL ratio), BMI, and weight with no positive effects on TC, dietary intake, PA, WC, and HC. Therefore, it may play a potential role in the prevention of macro and microvascular complications. Trial registration The project is a registered clinical trial (Registration number: IRCT20190902044671N1, Iranian Registry of Clinical Trials (IRCT), registered October 11, 2019. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-022-00792-2.