Super Food: Dark Chocolate for Improved Blood Pressure

This post is part of our "Super Foods" series and was submitted by David A. Mark, PhD, president of dmark consulting, LLC.

Chocolate tastes so decadent that we think it must be bad for us, but as it turns out, the right type of chocolate consumed in the right amount may actually have health benefits.

First, all chocolates are not created equal.  Milk chocolates, such as in the popular candy bars, are only about 10% to 20% cacao bean solids, the rest being milk and sugar.  Semi-sweet chocolate has a higher cocoa content, and dark chocolates are higher still.

Second, the higher cocoa content is important because the compounds thought to be healthy – part of group of plant-derived chemical compounds called flavonoids – are in cocoa.  These are the compounds that impart dark chocolate with its bitter taste and astringent mouth-feel.  The same compounds are found in red wine, green tea, dark-colored berries, and fruits, and the skins of bitter-tasting nuts, such as pecans and hazelnuts.  Two servings a day of most of these foods is enough to deliver a health benefit.

Third, what these compounds do in the body is relax arteries and make blood-clotting platelets less sticky.  Evidence for dark chocolate lowering blood pressure was most recently summarized by Karin Ried in "Does chocolate reduce blood pressure? A meta-analysis," published in the June 2010 issue of BMC Medicine.  For patients with hypertension, the average decreases in systolic and diastolic blood pressure were 5 and 3 mmHg, respectively.

Finally, hypertension is one condition for which medical science has many solutions – drugs that can be used singly or in combination to control elevated blood pressure with manageable side effects.  Any diagnosis of hypertension should be discussed with your doctor and acted on based on your doctor’s advice.  If you intend to start a habit of daily consumption of dark chocolate, mention this to your doctor, and understand that the expected effect is modest.  This should be viewed as a complementary approach, not one used as an alternative to drugs that are proven to work and are safe to use.

David A. Mark, PhD, is president of dmark consulting LLC, a Boston-area science consulting firm.  His many years of industry R&D experience include functional foods, dietary supplements, and sports nutrition products.

Flickr image from EverJean