The effect of Curcumin/Turmeric on blood pressure modulation: A systematic review and meta-analysis.

Hypertension is a chronic condition that can lead to several health problems, such as cardiovascular diseases, myocardial infarction, stroke, retinopathy and renal failure. In the present study, a systematic review and meta-analysis was undertaken with the main aim of estimating the quantitative effect of curcumin/turmeric supplementation on blood pressure (BP).A systematic search was undertaken in Medline, Embase, Scopus, ISI Web of Science, Google Scholar and Cochrane library up to May 2019 to identify randomized clinical trials assessing the effect of curcumin/turmeric on systolic BP (SBP) and diastolic BP (DBP). A random-effects model was used to analyze the impact of combined trials. Cochrane Risk of Bias Tool was applied to assess potential risks of bias.

A total of 11 studies comprising 734 participants were eligible and included in the meta-analysis to estimate pooled effect size. Results of the meta-analysis did not indicate any significant effect of curcumin/turmeric on SBP (-0.69 mmHg; 95% CI: -2.01, 0.64; I² = 18%) and DBP (0.28 mmHg; 95% CI: -1.12, 1.68; I² = 53%). However, subgroup analysis revealed a significant reduction only in SBP levels (-1.24 mmHg; 95% CI: -2.26, -0.22; I² = 0%) but not DBP (0.29 mmHg; 95% CI: -0.65, 1.22; I² = 1%) in studies with ≥12-week supplementation. No favorable effect of curcumin administration on SBP or DBP levels was found after stratification according to either participant's condition or type of intervention (turmeric, crude curcumin and high-absorption curcumin).

The present meta-analysis suggests that consuming curcumin/turmeric may improve SBP when administered in long durations. However, more studies are needed to confirm these results.