Does the thought of a sweet, dark chocolate bar make your heart flutter? It shouldn't — at least, not in the literal sense. According to recent research, the indulgence may help prevent an irregular heartbeat, so you have a new reason to eat chocolate on a (semi)regular basis. If that's not the best news you've heard all week, you must be having far better luck than the rest of the United States.
Previous research has suggested that foods containing cocoa can prevent heart disease, so in a study published in Heart on Tuesday, medical researchers looked at the association between chocolate consumption and atrial fibrillation (AF) in more than 55,000 middle-aged adults. According to the American Heart Association, AF is a "quivering or irregular heartbeat" that can lead to complications like blood clots or stroke, and it's even been linked to dementia. In the Heart paper, researchers pulled data from the Danish Diet, Cancer, and Health Study, analyzing how much chocolate participants said they ate on a regular basis. Using Denmark's national health registry, the scientists then followed up to see which participants developed AF in the years after the study. According to their analysis, 3,346 people went on to be diagnosed with the condition.
Here's the part you've been waiting for. When researchers compared the rate of AF diagnoses and cocoa consumption, they found that people who ate chocolate in moderation were less likely to develop heart flutters.
The obvious next question is this: How much chocolate can we stuff into our faces while still considering it "moderate" consumption? According to the study, eating about an ounce of chocolate each week overall was associated with 17 percent lower chance of developing AF, but gender played a role. For men, the effect was strongest when they ate two to six servings of chocolate per week. In women, it was strongest when they ate a single serving each week, because life is entirely unfair.
This is the first time a large-scale study has focused on the relationship between chocolate and AF in particular, but it's far from the only time research has found a link between cocoa and heart health. However, the recommended servings vary wildly from study to study. In contrast to the findings discussed above, researchers in the UK found in 2015 that middle-aged and older adults who ate up to 3.5 ounces of chocolate each day had lower rates of heart disease. In 2016, another study concluded that people who ate about an entire bar a day had reduced insulin resistance, which in turn reduced their risk for cardiovascular disease. The list of similar studies goes on and on (and on). Basically, there's no official, exact serving recommendation for heart health yet.
Many of these studies are correlational, meaning they can only show an association between cocoa and heart health; other factors could be at play. In 2010, however, a small trial found that when people drank cocoa with skim milk for a month, their cardiovascular health improved compared to people who didn't drink any cocoa.
Researchers believe that cocoa's antioxidants, particularly a class of compounds called flavonoids, are responsible for its anti-inflammatory effects. Unfortunately for anyone with a sweet tooth, though, darker varieties tend to be higher in flavonoids (and lower in fat) than milk or white chocolate. So if you're using healthiness to justify your chocolate indulgence, steer your grocery cart away from the ultra-processed candy aisle. Instead, look for the stuff that's as dark and bitter as your soul would be if chocolate didn't exist.