Effect of cocoa products on blood pressure: systematic review and meta-analysis.
Desch S., Schmidt J., Kobler D., Sonnabend M., Eitel I., Sareban M., Rahimi K., Schuler G., Thiele H.
BACKGROUND: Cocoa products such as dark chocolate and cocoa beverages may have blood pressure (BP)-lowering properties due to their high content of plant-derived flavanols. METHODS: We performed a meta-analysis of randomized controlled trials assessing the antihypertensive effects of flavanol-rich cocoa products. The primary outcome measure was the change in systolic and diastolic BP between intervention and control groups. RESULTS: In total, 10 randomized controlled trials comprising 297 individuals were included in the analysis. The populations studied were either healthy normotensive adults or patients with prehypertension/stage 1 hypertension. Treatment duration ranged from 2 to 18 weeks. The mean BP change in the active treatment arms across all trials was -4.5 mm Hg (95% confidence interval (CI), -5.9 to -3.2, P < 0.001) for systolic BP and -2.5 mm Hg (95% CI, -3.9 to -1.2, P < 0.001) for diastolic BP. CONCLUSIONS: The meta-analysis confirms the BP-lowering capacity of flavanol-rich cocoa products in a larger set of trials than previously reported. However, significant statistical heterogeneity across studies could be found, and questions such as the most appropriate dose and the long-term side effect profile warrant further investigation before cocoa products can be recommended as a treatment option in hypertension.