Researchers in Athens set out to investigate chocolate’s heart health benefits by investigating the effect of eating dark chocolate on three determinants of cardio-vascular performance: endothelial function (the lining of blood vessels), arterial stiffness, and wave reflections(5).

All three are predictors of cardiovascular risk. Their study found that soon after eating dark chocolate, wave reflections and endothelial function were both improved – a combination considered to be significantly cardioprotective. Soon after, their colleagues at the University of California published almost identical results(6).

In a separate study carried out at the University of L'Aquila in Italy, cocoa was found to lower blood pressure in patients with essential hypertension(7). Somewhat to the surprise of the experimenters, it also improved insulin sensitivity – an effect which would make cocoa and cocoa products very well suited to diabetics!

Within 12 months, a group at the University of Buenos Aires showed that the anti-hypertensive effect of cocoa was due to its ability to inhibit ACE, the same enzyme targeted by many antihypertensive drugs(8). At our own University of Dundee, dark chocolate was shown to reduce blood platelet activity, a generally desirable effect which reduces the risks of both heart attacks and stroke(9). (Milk and white chocolate were ineffective.) The University of Kuopio in Finland found dark chocolate increased levels of HDL, the healthy form of cholesterol(10).

Finally, in January ‘06, a team of scientists at the Harvard School of Public Health performed a meta-analysis of cocoa and chocolate studies and concluded that eating chocolate was indeed likely to reduce the risk of heart disease and stroke(11).

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