Effects of Curcumin/Turmeric Supplementation on Kidney Function in Individuals With Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

BACKGROUND

Curcumin and turmeric are widely studied for their potential renoprotective effects, but evidence regarding their impact on kidney function in individuals with diabetes remains inconsistent.

OBJECTIVE

To systematically evaluate the effects of curcumin/turmeric supplementation on kidney function parameters in subjects with diabetes.

METHODS

PubMed, Web of Science and Scopus were searched from inception until August 2025. Randomised controlled trials (RCTs) assessing the effects of curcumin/turmeric on serum creatinine, blood urea nitrogen (BUN), uric acid, urea and albumin in diabetic populations were included. Data were pooled using random-effects models and reported as weighted mean differences (WMDs) with 95% confidence intervals (CIs). Subgroup, sensitivity, and meta-regression analyses were conducted. Risk of bias was assessed using the Cochrane RoB 2 tool, and evidence certainty was evaluated via GRADE.

RESULTS

Twelve RCTs (n = 1303 participants) were included. Curcumin/turmeric supplementation did not significantly affect creatinine (WMD: -0.01 mg/dL, 95% CI: -0.03 to 0.01, p = 0.519) or BUN (WMD: -0.41 mg/dL, 95% CI: -3.15 to 2.33, p = 0.769). A trend toward reduction in uric acid was observed (WMD: -1.46 mg/dL, 95% CI: -2.93 to 0.02, p = 0.053). However, urea levels were significantly reduced (WMD: -2.53 mg/dL, 95% CI: -4.09 to -0.96, p = 0.002). No significant change was found in albumin (WMD: 0.07 g/dL, 95% CI: -0.02 to 0.17, p = 0.133). Subgroup analyses showed no significant moderating effects. Publication bias was detected for creatinine (Egger's p = 0.028). The certainty of evidence was moderate for creatinine, urea, and albumin, and low for BUN and uric acid.

CONCLUSION

Curcumin/turmeric supplementation significantly reduces urea levels but does not significantly affect creatinine, BUN, uric acid or albumin in individuals with diabetes. Further high-quality, long-term RCTs are needed to clarify its renoprotective potential and optimal dosing.