Chocolate Reduces Stroke Risk In Women.
There are no clinical trial data in women showing that chocolate affects stroke risk.
Dark chocolate is of great interest as a potentially healthy food choice that also tastes great. Dark chocolate contains flavanoids and is thought to impact positively on overall vascular health (3). The epicatechin content of cocoa is primarily responsible for its favorable impact on vascular endothelium via its effect on both acute and chronic upregulation of nitric oxide production (3).
There are no clinical trials looking specifically on the role of dark chocolate in risk reduction for stroke events in women. Available relevant data comes from three trials.
A collaboration between Yale and the Hershey Chocolate Company found that acute ingestion of solid dark chocolate and liquid cocoa improved endothelial function and lowered BP in overweight individuals (2). Endothelial function refers to the constriction and dilation of blood vessels in response to chemicals released by the lining of blood vessels. The study did not go on to see if these changes resulted in any clinically significant benefits such as stroke reduction. The authors cautioned that any benefits of dark chocolate could be offset by chocolate containing a high sugar content. Limitations of the study included a small sample size of 45 and a short duration of follow-up of just two hours after ingestion of cocoa.
The second study looked at the effect of 40 gm of cocoa powder on levels of pro-inflamatory biomarkers in 42 high risk volunteers (4). The study showed excellent adherence to the cocoa drink! However the results from the measured biomarkers of inflammation were inconsistent and there were no clinical outcome measures.
The third study of interest looked at lifestyle changes which included a 25gm bar of dark chocolate per day and compared carotid plus cerebral blood flow at baseline, 4 weeks and 20 weeks into the complex lifestyle intervention (1). This randomized controlled trial was conducted in 108 adults with atherosclerosis. The study found that lifestyle changes including a modified polyphenol-rich Mediterranean diet did not affect cerebral or carotid artery blood flow.
In summary, there is no clinical evidence to support benefits of dark chocolate in the reduction of risk of stroke in women.