Dark chocolate acts as a natural ACE inhibitor
The protective effect of cocoa against cardiovascular disease has been suggested by numerous studies. Multiple mechanism have been proposed, but researchers from the Linköping University have recently revealed one potential mechanism, as dark chocolate consumption inhibited an enzyme capable of increasing blood pressure.
Angiotensin I-converting enzyme (ACE) catalyzes the conversion of the inactive angiotensin I in the blood to the active angiotensin II. The active form makes the blood vessels contract, which builds up the pressure in the arteries causing high blood pressure (hypertension). Dark chocolate is rich in flavanols (e.g. catechin, epicatechin) and procyanidins, and it is suggested that these compounds have beneficial effects on cardiovascular disease. High blood pressure is one of the risk factors for cardiovascular disease, so one of the aims of the study was to investigate the effect of dark chocolate on ACE activity.
Sixteen healthy subjects, both male and female, were recruited for this study. They were not allowed to use nicotine containing products and medical and/or herbal drugs in the 2 weeks leading up to trial. In the last 2 days before the start of the study, they had to stay away from chocolate and other products containing similar compounds such as many types of berries, coffee, wine, tea and some types of fruit and vegetables. All participants consumed 75 grams of dark chocolate with a minimal cacao content of 72%, within approximately 5 minutes. To measure the effect of chocolate consumption on ACE activity, blood samples were taken before ingestion and after 30 minutes, 60 minutes and 3 hours. Blood pressure was also assessed at the same time intervals.
An 18% inhibition of ACE activity was observed three hours after dark chocolate ingestion, which is comparable with the effect seen in prescription ACE inhibitors. This effect might be due to the catechins in the chocolate, since their plasma values peak 2-3 hours after ingestion. No effect on blood pressure was observed, since blood pressure regulation is a long-term process and also because the healthy subjects had normal blood pressure values to start with.
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However, this study clearly demonstrates that dark chocolate consumption is capable of reducing ACE activity, in a magnitude similar to prescription ACE inhibitors. An optimal dose hasn’t been determined yet and chocolate isn’t exactly low in calories and fat either. Nevertheless, chocolate can be part of a healthy diet as long as the cocoa content is at least 70% and it is consumed in moderation. You can also use raw cocoa powder, which is lower in calories.
Excerpt image by el patojo
Persson, I. A. -., Persson, K., Hägg, S., & Andersson, R. G. G. (2011). Effects of cocoa extract and dark chocolate on angiotensin-converting enzyme and nitric oxide in human endothelial cells and healthy volunteers-A nutrigenomics perspective. Journal of Cardiovascular Pharmacology, 57(1), 44-50