Is chocolate good for the heart?
January 25, 2016
For many people, it was a stop-the-presses kind of moment. Could chocolate actually be good for your heart?
It wasn’t the first time this theory had been investigated. A number of studies have suggested that chocolate, especially dark chocolate, may be good for heart health. The latest study published in 2015 found evidence that higher chocolate intake may be associated with lower risk of future cardiovascular events.
These kinds of studies generate headlines, but they always make me cringe a little bit. We want to believe that chocolate is good for us. But I tell my patients to pump the brakes. There are three important facts to remember:
- If there is a true health benefit to eating chocolate, it’s substantially smaller than the benefits derived from eating fruits and vegetables.
- Portion size is crucial. Ten ounces of chocolate will have a different effect on your health, including increased calorie intake, than one ounce of chocolate.
- Not all chocolate is the same. Research suggests that dark chocolate is better for you than milk chocolate or white chocolate.
The latest research about chocolate and your heart
The 2015 study examining possible heart health benefits of chocolate included 11 years of data from almost 21,000 people in England.
During the study, people who ate chocolate were less likely to develop or die from heart disease than those who didn’t eat chocolate. Of the participants who ate the most chocolate, 12 percent developed or died from heart disease. Of those who didn’t eat any chocolate, 17.4 percent faced the same fate.
This is promising news for chocolate lovers, but it’s important to understand how the data were collected. Like other studies that have examined the possible health benefits of chocolate, this was an observational study. Observational studies rely on information provided by the participants, and participants are not randomly assigned to a control group.
Observational studies can provide important hints about biological events. But we have to be careful how we interpret the information. Simply because there may be a relationship between two things doesn’t mean one caused the other.
For example, some people who walk with a cane also have gray hair. Use of a cane and gray hair are associated, but canes do not cause gray hair. Something else is causing the gray hair, and even though both conditions exist, one did not necessarily cause the other.
That said, a number of observational studies from around the world have consistently reported that individuals who consume chocolate are at moderately diminished risk of developing heart disease. The fact that this observation has been reported consistently across different demographics suggests that there may be something there, in terms of a causal link.
The part of chocolate that may be healthy
While we don’t have absolute proof about the possible health benefits of dark chocolate, researchers believe they’ve identified the specific ingredient that’s good for you – a molecule called epicatechin.
Epicatechin is part of the flavonoid family. Flavonoids are plant-based nutrients that include antioxidants. Many foods contain flavonoids, including most vegetables, berries, and citrus fruits.
Epicatechin is derived from cacao, the key ingredient in chocolate. Eating foods rich in epicatechin is thought to lower your risk for heart disease, diabetes, cancer, and other common diseases.
One study published in 2009 looked at the diet of the Kuna Indians of Panama, which includes a high intake of flavanol-rich cocoa. The researchers knew the Kuna generally had very low blood pressure levels and were not developing heart disease, diabetes, or cancer as often as the general population.
One of the researchers involved with that study – a professor of medicine at Harvard Medical School – has stated his belief that epicatechin is so important that it should be considered a vitamin.
More testing is needed
Is it possible that people who eat chocolate are different in some way from those who do not? Do they eat more healthy foods? Do they exercise differently?
These are all questions we haven’t been able to answer with certainty.
While there is a substantial amount of evidence to suggest that chocolate has a modest benefit on heart health, it hasn’t been proven yet. The only reliable way to test the health benefits in humans is to enroll a large number of people in a program where some are randomly assigned to eat chocolate and others are randomly assigned to eat a chocolate-free diet. This is called a randomized controlled clinical trial – the same method used to test new drugs.
One such clinical trial expected to wrap up in 2020 will try to determine the effects of cocoa extracts and multivitamins on reducing heart disease and cancer. While this is not a study about the effects of eating chocolate, it may give us more clues.
For now, until we have more proof, I’ll be telling my patients who do eat chocolate to consume it in moderation.
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