Because they found snacking on a slab of the cocoa-rich treat inhibits an enzyme in the body that is known to raise blood pressure.
Researchers recruited 16 healthy non-smoking volunteers for the study. Two days before the study they were not allowed to eat chocolate or anything containing similar compounds, including many berries, nor could they drink coffee, tea, or wine. Everyone in the group gave a blood sample both before and after eating 75 grams of unsweetened chocolate with a cocoa content of 72 percent.
Scientists found ACE enzyme activity was reduced by 18 percent three hours after the cocoa dose. This is comparable to the effect of drugs that inhibit ACE and are used as a first-choice treatment for high blood pressure.
Drug researcher Ms. Persson said: "Our findings indicate that changes in lifestyle with the help of foods that contain large concentrations of catechins and procyaninides prevent cardiovascular diseases."