July 3, 2007 (Insidermedicine) Eating small amounts of dark chocolate a day helps lower blood pressure, say researchers in a report published in the Journal of the American Medical Association. 

Previous research has suggested that eating large quantities of dark chocolate can help to lower blood pressure. It is thought that a class of antioxidants known as polyphenols, found in plants, protect against high blood pressure. Approximately one in three US adults has high blood pressure and is at increased risk of stroke, heart attack, heart failure or kidney failure. Adopting healthy lifestyle habits is an effective first step in both preventing and controlling high blood pressure. This can include eating a diet rich in fruits and vegetables, regular exercise to maintain a healthy weight, and if necessary, medication.

To investigate the effect of eating small amounts of dark chocolate on blood pressure, researchers studied 44 adults with untreated high blood pressure. The participants were randomly assigned to receive either 30 calories of dark chocolate containing 30 mg of polyphenols or polyphenol-free white chocolate.

After 18 weeks they found a nearly 20% decrease in the prevalence of high blood pressure among the participants eating the dark chocolate. Eating dark chocolate dropped systolic blood pressure by 3mmHg and diaslotic by 2. Eating white chocolate had no effect on blood pressure.

It has been estimated that even a 3.0 mm mercury reduction in systolic blood pressure can reduce the risk of death from stroke by 8%, coronary artery disease death by 5%, and death from all causes by 4%.

Since many people have difficulty modifying their diet and lifestyle sufficiently to lower their blood pressure and reduce their heart disease risk, adding small amounts of dark chocolate to the diet may be a promising approach. Further research is needed to assess the effects of dark chocolate on the general population and to evaluate the long-term effects.

Reporting for Insidermedicine, I'm Dr. Susan Sharma.