Love Your Heart, Eat Chocolate
June 12, 2017
- People who consumed cocoa, especially dark chocolate, one to three times a month were less likely to be diagnosed with atrial fibrillation (AFib), also known as irregular heart rhythm
- Reduced atrial fibrillation risk for women was linked to eating one serving of chocolate per week, while the biggest reduction for men was associated with eating two to six servings per week
- More than 2.7 million people in the U.S. (33 million worldwide) suffer from atrial fibrillation, associated with an increased heart attack risk, heart failure, stroke and even cognitive impairment
- Make sure when you’re reaching for chocolate that you choose the dark variety, as milk chocolate is higher in sugar and lower in antioxidants and sometimes contains damaging artificial sweeteners
By Dr. Mercola
This may cause many a heart to leap, but chocolate, once again, has been placed in the “beneficial for your health” category. This time, quite fittingly, it’s your heart that may benefit from eating this most decadent of treats. Through the ages, benefits such as increased energy as well as libido have been attributed to chocolate, which has also been considered good for diarrhea and migraines, and treating syphilis and even cancer.
Some of these are even true; antioxidant catechins found in dark chocolate were found to be the active ingredient responsible for lowering lung cancer rates,1 as well as rectal cancer.2 According to a recent study in Denmark,3 people who consume cocoa one to three times a month were about 10 percent less likely to be diagnosed with atrial fibrillation, or AFib, the medical term for irregular heart rhythm, compared to people who ate chocolate less than once a month.
Elizabeth Mostofsky, an epidemiologist at the Harvard T.H. Chan School of Public Health, and a team of researchers analyzed the data and found “a significant association between eating chocolate and a lower risk of AF — suggesting that even small amounts of cocoa consumption can have a positive health impact.”4
The team’s new research, published in the journal BMJ Heart,5 showed a reduced risk of AFib for women who ate one serving of chocolate per week, while the biggest reduction for men was associated with eating two to six servings per week.
Previous studies in 20106 and 2015, known as the Physicians’ Health Study, had drawn no such conclusions, and the latter review involved 33,000 Americans.7 Eating cocoa and foods containing it may be heart beneficial due to the high number of antioxidant, inflammation-fighting and blood vessel-relaxing flavanols cocoa contains, the researchers concluded.
Flavanols are a subgroup of polyphenols found in tea, red grape skins and wine as well as chocolate, which are known to act as powerful antioxidants. Previous studies had already determined that not just cocoa, but dark chocolate, specifically, has the most flavanols to impart health advantages, including reduced inflammation that can cause tissue damage. Flavanols may also offset blood clots that form when irregular heartbeats permit blood in the heart to “pool up,” LA Times says.8
Eating dark chocolate is associated with decreased risk of heart attack, heart failure, cognitive impairment and even early death. But as studies go, scientists weren’t convinced it was actually the chocolate that prevented atrial fibrillation, evidenced by irregular heartbeats in the heart’s upper chamber, as the studies had been fairly thin.
Atrial Fibrillation: Studies, Symptoms and Risks
According to the American Heart Association, 2.7 million or more people in the U.S. suffer from atrial fibrillation, and a whopping 33 million suffer from it worldwide.9 It increases the risk of blood clots, which often result in strokes, heart failure, cognitive impairment and other problems in the individuals who have it. LA Times explained what it is:
“Atrial fibrillation is believed to result from the release of certain molecules that ultimately damage heart tissue. That damage changes the way electrical signals travel through the chambers of the heart, causing one’s heartbeat to flutter instead of beating in a steady rhythm.”10
Unfortunately, 25 percent of adults are projected to develop the condition in their lifetime, according to Drs. Sean Pokorney and Jonathan Piccini, cardiologists at Duke University Medical Center, who published an editorial that ran alongside the study results. Researchers scrutinized data from 55,502 men and women in Denmark between the ages of 50 and 64 years old at the time the long-term study began.
Each provided information detailing their dietary habits between 1993 and 1997. The data collected was then linked to Denmark’s national health registries to find which ones were diagnosed with atrial fibrillation. It was found that 3,346 of the cases occurred over 13.5 years. Scientific American reported:
“Based on their diets at the beginning of the study period, people who ate one serving, about 1 ounce (28.35 grams), of chocolate per week were 17 percent less likely to be diagnosed with atrial fibrillation by the end of the study than people who reported eating chocolate less than once a month.
Similarly, those who ate 2 to 6 ounces per week were 20 percent less likely to be diagnosed with atrial fibrillation while those who ate more than an ounce of chocolate a day were 16 percent less likely to have the condition.”11
Other Factors to Consider Regarding Chocolate Consumption
Interestingly, researchers didn’t examine related factors such as sleep apnea or kidney disease, which may influence atrial fibrillation, and they had no data on whether the subjects consumed milk chocolate or dark chocolate, so as a result, the amount of flavanolsconnected to the chocolate they ate also was unavailable.
However, the data suggests that people who ate more chocolate also consumed more calories, but had a lower body mass index (BMI) — the measure of weight in relation to height — compared to those who ate the least chocolate.
Alice Lichtenstein, director and senior scientist at the Cardiovascular Nutrition Laboratory at Tufts University, who was not part of the featured study, noted the likelihood that the people in the first group may have also been more physically active. Pokorney and Piccini said the study results were interesting and worth further consideration in spite of its limitations, noting:
“A double-blind randomized controlled trial is needed to evaluate the true efficacy of chocolate for the prevention of (atrial fibrillation) and such a trial would need to incorporate quantified doses of cocoa.”12
Does the Type of Chocolate You Eat Really Matter?
There are several types of chocolate: Dark chocolates and the milk-based kind have both been mentioned, but there’s also white chocolate to consider, and other ingredients that may either make or break its ability to be considered something healthy to consume. It’s true that as good as chocolate may be for you, it often contains large amounts of sugar, as well as “bad” fats, including trans fats and partially hydrogenated oils that could contribute to chronic disease.
Dark chocolate, on the other hand, usually contains more cocoa solids. Knowing that, Mostofsky expressed doubt regarding whether the milk chocolates Danes typically eat would return any positive results from the study, but the researchers learned something new.
She noted, “We were pleasantly surprised that — despite the fact that most of the chocolate may have had relatively low cocoa concentrations — we were still able to see robust findings.”13 The La Times noted something that is very significant from Mostofsky’s study:
“The authors wrote that their study may have turned out differently than the previous ones because chocolate in Denmark contains more cocoa — the suspected beneficial ingredient — than it does in the U.S. Here, milk chocolate must have at least 10 percent cocoa solids, and dark chocolate must have at least 35 percent. In Denmark, the requirements are 30 percent and 43 percent, respectively.
Another difference is that the new study measured cases of ‘clinically apparent’ atrial fibrillation that were recorded in Denmark’s national health records. The American studies relied on self-reports of AF.”14
That’s certainly not to say that chocolate now allows people carte blanche in the noshing category. Tom Sherman, director of biomedical sciences at Georgetown University Medical Center (who did not take part in the study), suggested that chocolate lovers stick to eating no more than “a nice, 1-ounce piece of chocolate.”
Just don’t take it too far, Mostofsky said, because even though there’s a substantial link between eating chocolate and a lower risk of AFib, “Eating excessive amounts of chocolate is not recommended because many chocolate products are high in calories from sugar and fat and could lead to weight gain and other metabolic problems.”
What to Look for in Chocolate
It’s always wise to read labels to know exactly what’s in the packages you buy, and it’s true with chocolate, as well. One ounce of milk chocolate chips, according to Nutrition Data,15 contains an average of more than 14 grams of sugar! In comparison, the same amount of dark chocolate, with 70 percent to 85 percent cacao solids, contains 6.7 grams of sugar.16
Make sure the chocolate you consume doesn’t contain artificial sweeteners such as aspartame, found to cause serious chronic neurological disorders and numerous other acute symptoms, from migraines to blurred vision to anxiety attacks. A CNN article noted that when it comes to chocolate, “white” chocolate contains no cacao at all, and a bar labeled “70 percent cocoa” may have different amounts of the flavonoids you’re looking for.
Further “chocolate that has gone through a chemical step known as dutching, also known as Dutch chocolate, has essentially lost all traces of these compounds.”17 As for net carbs contained in chocolate, it’s important to determine by reading labels the amount of grams of carbohydrates, subtracting the dietary fiber, then subtracting the sugar alcohol if it applies.
Something to remember, too, is that the important thing is the total carbs minus fiber (i.e., net carbs). Fiber is crucial not just to keep your colon regulated, but for overall health as well.
Especially if you’re not paying attention to the labels, the chocolate you reach for will most likely contain high amounts of sugar, Mostofsky asserted. “But moderate intake of chocolate with high cocoa content may be a healthy choice.” Perhaps because of this, there’s a body of scientists now dedicated to determining whether a “chocolate pill” made with cocoa extract might be the next big thing.
To get the greatest health benefits of chocolate by consuming a whole food instead of a pill, raw cacao butter (the fat component of the cacao seed) or raw cacao nibs are excellent options.