A recent study shows that people who regularly consume 70 percent dark chocolate show a marked improvement in blood flow, while no improvement is observed in those who eat “processed” chocolate, which contains very little cocoa paste. The positive effect of dark chocolate appears linked to a property in its polyphenols that releases a chemical messenger, nitric oxide, which increases arterial dilatation, at the same time improving blood flow and reducing platelet aggregation.
However, it is important to note that previous studies have shown that milk prevents the absorption of dark chocolate’s polyphenols, thereby neutralizing its beneficial effects. Milk contains large amounts of casein, a protein that interacts with polyphenols and prevents them from being efficiently absorbed by the intestine. It is therefore always preferable to consume dark chocolate unaccompanied by milk. A similar phenomenon is observed with tea: While consumption of tea leads to a significant improvement in the ability of arteries to dilate, which confirms that the polyphenols contained in tea have a positive effect on the cardiovascular system, adding milk completely reverses this effect and neutralizes its positive effects on the cardiovascular system.