Dark chocolate may lower blood pressure

(CNN) -- Eating a little dark chocolate each day may be good for the heart, but only if you grab your running shoes in one hand and an apple in the other.

New research found that people who ate dark chocolate or cocoa for short periods of time saw a slight drop in blood pressure. But there is a caveat: If you eat these treats, you need to make sure you're doing all of the right things to stay healthy, such as exercising, eating right and -- if you're on blood pressure medicine -- taking that as well.

The study

Scientists in Melbourne, Australia, curious about the role of dark chocolate in heart health, looked at 20 studies in which adults ate dark chocolate or cocoa. More than 850 people participated in the trials that generally ran from two to eight weeks.

People ate different amounts of dark chocolate, ranging from a small piece to a large bar or a cup of cocoa, but almost all of the chocolate was high in cocoa - therefore high in antioxidants called flavanols. And that's important because antioxidants play a role in opening up our blood vessels, which reduces blood pressure.

Results

People who ate dark chocolate or cocoa had blood pressure readings that were 2 millimeters of mercury lower than those who ate little or no chocolate. This means that a blood pressure reading of 120/80, for example, dropped to 118/78. This is a small decrease, and scientists say that though chocolate will certainly not replace blood pressure medicines, it may play some role.

"Moderate regular dosages of flavanol-rich cocoa products such as dark chocolate may be part of a comprehensive lifestyle plan to optimizing blood pressure," explains study author Dr. Karin Ried, Research Director of the National Institute of Integrative Medicine, Melbourne, Australia.

But experts aren't sure what this means in the long run.

"We do not know yet whether dark chocolate is associated with a reduction in blood pressure in the long term (important since high blood pressure is a chronic condition), and whether this will translate into a reduction in adverse clinical outcomes such as heart attack and stroke," says Dr. Lorri Puil, an editor at the Cochrane Hypertension Group.

The results are published online in the Cochrane Library, which is part of the Cochrane Collaboration that provides internationally recognized research on human health.

Take away

Chocolate is high in fat, calories and sugar so if you eat it, do so in moderation. One suggestion is to substitute dark chocolate for other high-calorie foods or desserts that you already include in your diet. But remember, if eating dark chocolate adds to your overall calories for the day, you'll likely put on weight-- which is not good for overall health.

But if you do choose dark chocolate, registered dietitian Rachel K. Johnson, a spokesperson for the American Heart Association, offers this advice.

"To control the calories, opt for chocolate with a high cocoa content - look for one 70% or higher. It's intensely flavored, and thus a smaller amount may satisfy you," Johnson says. " If you use cocoa powder in cooking or to make hot chocolate, choose natural cocoa powder rather than alkalized cocoa power (also called Dutch-processed). The natural cocoa power has more of the beneficial flavanols."

But experts say we do have other choices. Apples, blackberries, beans, apricots and green tea are also packed with antioxidants and don't contain the unhealthy fats in chocolate.

Researchers know that despite the pros and cons of eating dark chocolate, that they don't have all of the answers. They do agree that more studies are needed.

A little history

The link between cocoa and blood pressure was first noticed in the indigenous people of San Blas Island in Central America, who drink flavanol-rich cocoa drinks every day and had normal blood pressure no matter their age.