Imagine that you are sitting down to eat an antioxidant-rich food that has been proven to provide significant benefit to your heart health. What do you see on your plate — a fresh green salad sprinkled with beautiful vegetables? Brown rice sautéed with chicken and broccoli? Now imagine that the food is also so delicious that it seems more like a decadent treat than a health promoter. What could this magic food possibly be? Chocolate. Dark chocolate, to be precise.
What Makes Dark Chocolate So Good for You
The primary health-promoting benefit of dark chocolate comes from its high levels of flavonoids — potent antioxidants also found (albeit in lower amounts) in tea, red wine, and apples. Antioxidants are important because they protect cells and tissues from damage by free radicals, which are unstable molecules that can alter and weaken cells. Consider them as an insurance policy against the wear and tear that comes from stress, poor diet, and the inevitable process of aging.
Dark chocolate also contains significant amounts of two important minerals: A 1.5 ounce serving of dark chocolate provides 15 percent of the recommended daily allowance (RDA) of magnesium (important for energy production, strong bones, relaxed muscles, and effective nerve transmission), and 34 percent of the RDA of copper (which helps the body create the chemical messengers known as neurotransmitters and is associated with a lowered risk of developing cardiovascular disease).
As if that’s not enough, this near-magic treat promotes cardiovascular health in the following ways:
• Improves blood flow and protects arteries. A 2007 Swiss study of heart transplant patients found that the diameter of their coronary arteries was significantly increased after eating a single dose of dark chocolate. Which means that dark chocolate has a healthy effect on these important arteries that supply life-sustaining oxygen to the heart. A 2007 study by Chinese researchers found that participants who ate approximately 1.5 ounces of dark chocolate daily for two weeks significantly improved coronary blood flow. "Blood flow is vital to heart health because the blood carries oxygen, and oxygen is fuel for cells," explains Tom Morledge, MD, of the Center for Integrative Medicine at the Cleveland Clinic. Consider that the heart pumps 24 hours a day, 365 days a year, and it's easy to see why an optimum source of energy is important to its function. On the other hand, eating a fast food hamburger with all the trimmings can cause the arteries in our bodies to have impaired function within an hour.
• Prevents blockage of the arteries. LDL, or "lousy," cholesterol becomes harmful if it is damaged by free radicals, which changes the structure of the LDL, causing it to become oxidized LDL cholesterol. Oxidized LDL cholesterol is then taken up by inflammatory cells that are in the lining of the arteries. The more accumulation, the more likely it is to form blockages that can impede blood flow or clots that can rapidly form, which trigger a heart attack. "Many studies suggest that the flavonoids in dark chocolate decrease the free radical damage of LDL cholesterol," Dr. Morledge says. In addition, the flavonoids have a similar effect to aspirin. "Flavonoids are a natural blood thinner and affect platelets which can cause clots that lead to heart attacks.” We don’t know yet whether dark chocolate can actually prevent a heart attack, but some recent studies suggest that this might be the case.
• Raises levels of good cholesterol. HDL, or "healthy," cholesterol works to moderate overall levels of cholesterol, and even small increases in HDL can lead to significant reduction in risk of developing heart disease. "For every 1 milligram improvement in HDL cholesterol, you get a 2 percent reduction in the risk of a heart attack," Dr. Morledge says. Although studies present conflicting evidence about the full impact dark chocolate on HDL levels, several studies have linked dark chocolate consumption with higher HDL.
An Added Bonus
Although chocolate devotees won't be at all surprised to hear it, research has also shown that dark chocolate can enhance mood and promote cognitive function: A 2004 study from British researchers found that participants who ate dark chocolate performed significantly better on visual tests that required quick reaction times and reported a noticeable uptick in their mood and energy levels.
Dark Chocolate Versus Milk Chocolate
Hate to break it to milk chocolate fans, but all this great news about the health benefits of chocolate does not apply to milk chocolate. There are two primary reasons: First, the benefits of chocolate come from the cocoa bean itself, and dark chocolate typically contains two to three times as much cocoa content than milk chocolate. Second, while both dark and milk chocolate contain high levels of saturated fat, the saturated fat in dark chocolate is primarily stearic acid, which comes from cocoa butter and has been found to have a neutral impact on cholesterol in humans. While milk chocolate also gets some of its fat from heart-healthy cocoa butter, it also gets some from milk, which contains saturated fat that is linked with higher cholesterol levels.
Milk chocolate also contains more sugar than dark chocolate, which may explain why a 2008 study conducted at the University of Copenhagen found that dark chocolate provides long-lasting feelings of fullness and reduces cravings for unhealthy foods, while milk chocolate caused people to consume more calories later and crave sweets, salty, and fatty foods. When you consume large amounts of sugar, it causes blood sugar levels to spike and then drop — the plunge then cues the body to seek more blood sugar, which translates into unhealthy cravings. Fatty foods and carbohydrate rich foods also stimulate that reward system of the brain and result in cravings which can result in overeating.
The Pretend Chocolate
And then there’s white chocolate, which is not really chocolate at all. White chocolate is a confection based on sugar and fat (either cocoa butter or vegetable oils) without the cocoa solids. And without the cocoa solids, you’re missing the key ingredient. Therefore, it shouldn’t come as a surprise that a recent study showed zero health benefits from eating white chocolate.
How Much Is Healthful?
The first step to making sure that your dark chocolate consumption is indeed good for you is to consume an appropriate serving size. "Dark chocolate still has calories, after all," Dr. Morledge says, "so you don't want to eat so much of it that you gain excess weight, which is a risk factor for developing heart disease." Most of the studies that have measured the health benefits of dark chocolate have used serving sizes of approximately 1.5 to 3 ounces — look at the nutritional information on the back of the bar before you start eating to decide how much you'll consume. "We don't know how much or often you should eat it, whether it's once a week, once a day, or somewhere in between," Dr. Morledge says. "I tell people to keep the saying 'Everything in moderation' in mind when they're deciding how much to eat and when."
Perhaps the best way to add dark chocolate to your diet is as a replacement for other sweets you may be consuming — you'll likely be eating fewer calories, consuming substantially fewer grams of sugar and sodium, and getting a lot more fiber if you opt for more traditional desserts. Not convinced? Compare the numbers on dark chocolate, carrot cake, a chocolate chip cookie from Starbucks, and a 1.5 ounce of Hershey's milk chocolate for yourself:
|| Serving Size
| Dark Chocolate
|| 1.5 ounces
|| 12 grams
|| 5 mgs
|| 5 grams|
| Milk Chocolate
|| 1.5 ounces
|| 24 grams
|| 35 mg
|| 1 gram|
| Carrot Cake
|| 27 grams
|| 320 mg
|| 2 grams|
| Chocolate Chip Cookie
|| 1 cookie
|| 34 grams
|| 300 mg
|| 3 grams|
When you are shopping for a dark chocolate bar, let the cocoa content be your guide — it is typically listed prominently on the label, and you want a bar with at least 70 percent cocoa beans. The higher the percentage, the more antioxidant content. If you really want to prioritize the antioxidant content, consider buying cocoa powder — it has the highest concentrations of flavonoids of any dark chocolate product.