Why that dark chocolate bar may be good for your health

But you won’t get the same benefits if you eat too much of the wrong kind of chocolate. Many of our favorite chocolates, including those found in many red, heart-shaped boxes, are ultra-processed candy full of added sugar, milk and tropical oils, or even milk or white chocolate. Overdo it, and you may experience heartburn, stomach upset and, over time, weight gain.

“It depends on which chocolate you choose,” said Uma Naidoo, a nutritional psychiatrist and biologist, professional chef, and author of “This is Your Brain on Food: An Indispensable Guide to the Surprising Foods That Fight Depression, Anxiety, PTSD, OCD, ADHD and More.” “A candy bar is not the same as a square of extra-dark natural chocolate. Dark chocolate, in moderation, can be a healthy addition to the daily diet.”

Flavonoids are found in cacao beans and cocoa: terms used interchangeably, but which actually are different. Cacao is the raw material — the beans — that comes from the tree, while the latter results from grinding the beans into a powder, then roasting, and combining with other ingredients, such as sugar, to make chocolate.

Countless studies suggest that flavonoids — including flavonoid subtypes such as flavonols and flavan-3-ols — can lower the risk of heart disease, high blood pressure and diabetes; improve mood; and lessen the symptoms of depression. Flavonoids also can help cognition, as well as counteract cognitive deficits that result from sleep deprivation. One study, the large placebo-controlled randomized COcoa Supplement and Multivitamin Outcomes Study (COSMOS) trial, found no difference in cardiovascular “events,” such as heart attacks, but did show a reduction in heart-disease-related deaths.

Davide Grassi, associate professor of internal medicine at the University of L’Aquila in Sant’Omero, Italy, who has conducted numerous studies examining the health effects of cocoa, agreed. “Cocoa is not the same as the chocolate that we eat every day,” he said. “Flavonoids are good for our blood vessels and overall health and may help reduce the risk of heart problems and other chronic diseases.”

But it’s important to distinguish natural cocoa, which comes from the cocoa bean in the rainforests, from processed chocolate, which is made by combining cocoa with sugar and other ingredients, he said.

Consider using plain cocoa powder in drinks or baking. “I use it to make energy balls,” said Julia Zumpano, a dietitian with the Cleveland Clinic. “I mash it up with almond butter and dates, make them into balls, and refrigerate them. It’s a great way to get cocoa powder with no saturated fat or added sugar. They’re phenomenal.”

How to pick the right chocolate

Dark chocolate often contains high amounts of cocoa, less sugar and more flavonoids, experts said. Very dark chocolate is the healthiest form of chocolate you can eat. It’s usually lower in sugar than other forms of chocolate and doesn’t contain milk or added fats.

“The darker the better,” said Eric Rimm, professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health. “Milk chocolate has less dark chocolate, and white chocolate has no chocolate at all.” (White chocolate typically is made of cocoa butter, sugar, milk solids and milk fat — but no solid cocoa.)

It’s not clear how much daily chocolate someone would have to eat for health benefits, since research uses pure cocoa and not commercial chocolate. The latter is processed, which can destroy flavonoids, and contains additives.

“The amount of flavonoids in the COSMOS study would require 600 to 700 calories a day of dark chocolate, and more than 5,000 calories a day of milk chocolate,” said JoAnn Manson, co-leader of COSMOS and a professor of medicine at Harvard Medical School. “You’re talking about a large amount of calories, and not a guaranteed content of flavonoids.”

Here’s how to eat dark chocolate

• Look for dark chocolate with a label promoting it as 70 percent or more cocoa. Some experts think higher — 80 percent or more — is even better, as more cocoa usually means less sugar. “If you’ve ever had 85 percent dark chocolate, there’s a natural stopping point,” said Zumpano. “Most people would struggle to eat a whole bar.”
• Keep in mind that labels won’t tell you the concentration of flavonoids. The darker the chocolate, the more flavonoids it is likely to contain.
• Consider eating at least one square of dark chocolate (about one ounce) every other day. Some experts recommend one to two squares daily.
• Limit milk chocolate and white chocolate. “Think of white chocolate as white bread,” said Cathy Deimeke, a registered dietitian and health education manager at UC Davis Health.
• If you’re concerned about sustainability and labor practices in cacao harvesting and production, look for Fair Trade, Rainforest Alliance or UTZ certification on the label.

Don’t forget the joy of chocolate

Chocolate should not be regarded as a “health” food in the same sense as fresh fruits and vegetables, but no one should feel the need to deprive themselves, experts said. “We definitely don’t want to discourage anyone from eating chocolate because it provides people with joy and happiness,” Manson said.

Rimm agreed. “It would be a shame to turn chocolate into medicine when there are other acute pleasures that occur from its consumption, whether it triggers great memories or just reminds someone of a connection,” he said. The research is interesting, although more long-term studies of chocolate may be necessary, he said, adding: “It’s a tough job, but I am happy to volunteer.”

Moreover, they said, even the occasional lapse is okay, especially for love. Grassi, for example, mostly sticks to dark chocolate. “Nevertheless, on some occasions, I prefer to eat milk chocolate, should I be in love at the time,” he said.

Do you have a question about healthy eating? Email [email protected] and we may answer your question in a future column.

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