By Jennifer J. Brown, PhD, Everyday Health
Photos by iStock Photo; iStock Photo; Getty Images
Evidence is building that products of the cacao plant, especially dark chocolate, are good for your heart. Medical studies show that people who eat dark chocolate have healthier cardiovascular systems, boasting better blood circulation and lower blood pressure and cholesterol levels. Cardiologist and Everyday Health columnist T. Jared Bunch, MD, recommends chocolate as part of your strategy to keep the world’s No. 1 killer disease at bay. “Dark chocolate should be included in a life plan that includes exercise, eating healthy foods that are largely plant-based, getting adequate sleep, stress reduction, and maintenance of weight,” says Dr. Bunch. Here, we explore the science behind dark chocolate’s benefits for the heart.
Cacao to Prevent Heart Diseases
Early signs that cacao is a heart-healthy food came from the unusually healthy elders of the island population of Kuna Indians in Panama. They drank large amounts of unprocessed cacao — about four cups each day — and were free of heart diseases, according to a study in the Journal of Cardiovascular Pharmacology. When they moved to cities, adopted Western ways, and gave up traditional cacao drinks, the Kuna developed high blood pressure in old age like the rest of us. Many studies, including 20 on blood pressure effects alone, show links between chocolate and markers of good heart health. Caution with cacao is advisable if you are prone to migraine headaches, because chocolate may be a migraine trigger. And people with chocolate allergies should not eat any type of cacao product. This includes raw cacao, cacao nibs or powder, dark chocolate, or milk chocolate.
Powers Heart and Blood Vessel Cells
Seeds of the Theobroma cacao plant, the source of dark chocolate, are rich in active compounds known as antioxidants. Dark chocolate is in the top 10 dietary sources of antioxidants, along with seasonings like cloves, mint, anise, cacao powder, and berries like black chokeberry and black elderberry, according to the European Journal of Clinical Nutrition. Dark chocolate is also rich in bioactive flavanols and theobromine. These have good effects on the cells of our hearts and blood vessels, found researchers at the University of Mississippi. A caveat if you are watching your fat intake: One ounce of dark chocolate, though low in cholesterol at only 2 mg, has about 9 gm of fat. “In general, the health benefits outweigh the risk of the additional calories,” says Bunch. “When you consume dark chocolate that is more than 70 to 80 percent pure, the calories are relatively low,” he adds. In less concentrated forms of chocolate — such as white or milk chocolate — other ingredients add lots of calories, and there are no documented heart benefits.
Boosts Blood Circulation
More evidence for the antioxidant benefits of dark chocolate comes from a July 2014 study carried out in Rome and published in the Journal of the American Heart Association. The research showed that eating dark chocolate helped people who have peripheral artery disease, PAD, walk farther and longer. PAD decreases blood flow to the arms and legs. Because of this, patients often have painful cramping and difficulty with exercise, even with walking. In the study, people with PAD who ate 40 gm (1.5 oz.) of dark chocolate a day were able to walk 11 percent farther and for 15 percent longer than people who ate the same amount of milk chocolate. The dark chocolate used in the study contained more than 85 percent cacao and was rich in active compounds known as polyphenols. Researchers looked at markers of oxidative stress in the blood, and found improvement for those who had the dark chocolate.
Calms Blood Pressure
Good news if your blood pressure has continued to climb over the years — eating dark chocolate is linked to significantly lower blood pressure. This is according to an extensive analysis of 20 randomized controlled trials, published as a Cochrane Review. Most of the studies were short-term. But even one 18-week trial showed a significant drop in blood pressure. In that study, people ate about 6 grams (only 1/4 of an ounce) of dark chocolate daily. Researchers compared them with others who ate the same amount of white chocolate. Dark chocolate was the clear winner. Systolic blood pressure (the top number) for people who ate dark chocolate went down by three points. Diastolic (the bottom number) blood pressure went down by two points. If you’re tracking yours, keep in mind that the normal blood pressure to aim for is less than 120/80, according to the American Heart Association.
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Lowers Stroke Risk
New data shows eating chocolate comes with a lower risk of stroke, according to researchers in Finland. Stroke is a major health concern for many, especially people with atrial fibrillation. Their stroke risk is five times that of people who don’t have afib, according to the National Stroke Association. When a blood clot forms in the brain, or a blood vessel bursts, the result is stroke — a leading cause of disability in the United States. In the Finnish study, researchers followed a group of more than 37,000 men for 10 years and counted instances of stroke. The numbers showed that those who ate about 63 grams (2 oz.) of chocolate per week had a lower risk of stroke, compared with those who ate no chocolate. And five additional studies also showed lower stroke risk — on average by about 20 percent for chocolate eaters. “Dark chocolate helps reduce blood pressure and may have a role in coronary artery disease stability and diabetes,” says Bunch. “So dark chocolate may help lower stroke risk.” However, warns Bunch, don’t stop taking a prescription blood thinner or anticoagulant — the only treatments proven to prevent stroke — and eat chocolate instead.
Helps You Meet Cholesterol Goals
If you’re struggling to get your cholesterol under control, studies on blood cholesterol levels and chocolate are heartening. In one trial, people with high blood pressure ate 100 grams (about 3 1/2 ounces) of either dark chocolate or white chocolate. Those who had the dark chocolate saw an average drop of 12 percent in their LDL cholesterol, which is known as “bad cholesterol” and linked to higher risks of heart disease. In a Dutch trial, people who ate dark chocolate had a significant increase in HDL, or “good cholesterol.” Researchers credited these healthy changes to theobromine, a compound found in cacao.
Relieves Stress on Your Heart
An often overlooked, but very real, risk factor for heart disease is stress. You’ll be happy to know that the solace provided by dark chocolate is not limited to its good taste. A June 2014 study found that eating dark chocolate helped people cope with stressful situations. Researchers measured people’s stress hormones — cortisol and epinephrine. Then they challenged people to do things like figure out a difficult math problem in their heads. Those who had the dark chocolate had lower levels of stress hormones circulating in their blood after the stress test. They also reported that they felt less stress. Blunting the effects of stress on the body is yet another way dark chocolate can protect heart health — good news even for people with a heart condition. “Dark chocolate has been shown to favorably impact some of the risk factors for atrial fibrillation, such as high blood pressure, body inflammation, and the response of the body to stress,” says Bunch.
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This article originally appeared on EverydayHealth.com: 7 Heart-Healthy Perks of Dark Chocolate