American Journal of Hypertension 2010 (Jan); 23 (1): 97–103
Desch S, Schmidt J, Kobler D, Sonnabend M, Eitel I,
Sareban M, Rahimi K, Schuler G, Thiele H.
Department of Cardiology,
University of Leipzig-Heart Center,
The evidence supporting the antihypertensive effects of cocoa has been building over the last few years, and this systematic review and meta-analysis of 10 randomized controlled trials, comprising 297 individuals confirms the BP-lowering capacity of flavanol-rich cocoa products. The high level of flavanols found in the cocoa plant is believed to be responsible for the lowering of blood pressure.
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.