Beneficial effects of nano‐curcumin supplement on depression and anxiety in diabetic patients with peripheral neuropathy: A randomized, double‐blind, placebo‐controlled clinical trial

Depression in patients with diabetes is associated with poor glycemic control and linked to an increased risk for diabetes complications such as neuropathy. Curcumin has shown potential antidepressant‐like activities in some studies. The present study is the first randomized controlled trial to test the efficacy of nano‐curcumin supplementation on depression, anxiety, and stress in patients with diabetic polyneuropathy. Eighty patients with diabetes were enrolled in this parallel, double‐blind, randomized, placebo‐controlled clinical trial. The participants were allocated randomly to the intervention ( n = 40) and control ( n = 40) groups. They received 80 mg of nano‐curcumin or placebo capsules daily for 8 weeks. At baseline and end of study, anthropometric measurements, dietary intake, physical activity, glycemic indices, and severity of neuropathy were assessed. The depression, anxiety, and stress level were measured by Depression, Anxiety, Stress Scale (DASS‐21‐items) questionnaire before and after the intervention. After intervention, there was a significant reduction in the mean score of depression in the nano‐curcumin group (from 16.7 [3.1] to 15.3 [2.6]) compared with placebo group (17.5 [3.2] to 17.3 [3.1]; p = .02). In addition, a significant fall was found in the mean score of anxiety in the nano‐curcumin group (from 22.4 [4.03] to 20.6 [3.4]) compared with the placebo group (21.9 [3.5] to 21.2 [3.5]; p = .009). Changes in stress score were not statistically significant between the two groups. These findings suggested that nano‐curcumin supplementation for 8 weeks was effective in reducing depression and anxiety scores in patients with diabetic polyneuropathy.