What Do We Really Know About Chocolate's Health Benefits?

August 16, 2017

This is an excerpt from Bean-to-Bar Chocolate: America’s Craft Chocolate Revolution, available next month.

I have a fantasy in which I eat chocolate all day and am healthier and happier than I ever thought possible.

Judging by the hundreds of articles published about chocolate’s health benefits every year, this seems like a reality. It’s true that cocoa has more antioxidants (in the form of polyphenols and flavanols) than red wine, tea, and many berries. Cocoa has the potential to, among other things, lower blood pressure, increase muscle function, improve metabolic function, improve cognition, and help guard against memory loss, and its anti-inflammatory effects are off the charts. That’s exciting stuff!

Please take us to this place. Photo by Julia Gartland

But a lot of the studies cited to support these claims are—how do I put this—bunk. For example, in 2016 the New York Times reported that chocolate can boost physical performance based on a study of eight people. That tiny sample size isn’t unusual in this kind of research. Further, many of the studies rely on questionnaires and other imperfect ways of gathering data, like asking participants how much chocolate they eat per week and whether it’s milk or dark. I don’t know about you, but I couldn’t tell you how much chocolate I ate this past week with any accuracy, and even if I could remember, I might downplay it out of sheer embarrassment.

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That’s why, at Harvard Medical School, Dr. JoAnn Manson is conducting the first large-scale study on the ability of cocoa flavanols to reduce the risk of heart attacks, memory loss, strokes, and other illnesses. She’s giving cocoa flavanols or a placebo to 18,000 people for four years, probably until about 2020, and monitoring the effects. People tend to think that the more antioxidants, the better. But that’s simply not true. “More is not necessarily better, and in fact more can be worse,” Manson explained. Based on prior research, she and her team have discovered that 600 milligrams of cocoa flavanols is the ideal amount to get the benefits and avoid side effects.

But before you get jealous of these folks in the study, keep in mind that they’re not gorging on chocolate; they’re taking two pills of isolated flavanols per day. “Chocolate is not a reliable source of high amounts of cocoa flavanols,” Manson said. In fact, it’s harder than you’d think to get 600 milligrams of flavanols from actually eating the stuff. Here’s why:

  • Depending on the type of cacao, there can be a 50 percent variation in polyphenols.
  • The fermentation process reduces the polyphenols by up to 50 percent.
  • Sun-drying the beans reduces the remaining polyphenols by up to 25 percent.
  • Roasting the beans reduces the remaining polyphenols by up to 20 percent.
  • Grinding and refining the nibs into chocolate liquor reduces the polyphenols by up to 10 percent.

Because you’re probably wondering, even “raw” chocolate and cocoa nibs have gone through fermentation and drying. All cocoa nibs, cocoa powder, and chocolate that we eat, in fact, has been fermented and dried, and almost always roasted, too.

Okay, but let’s say you still want to eat chocolate to get some good stuff in your diet. To get 600 milligrams, the ideal amount of flavanols, each day you’d need to eat...

Photo by Amber Day

Man, that’s a lot of chocolate. As Manson said, “Having chocolate in moderation is perfectly fine as a treat, but I don’t think it should be considered a health food.”

Megan’s book, Bean-to-Bar Chocolate: America’s Craft Chocolate Revolution, will be available next month.

Do you believe celebrities who claim to be satisfied by one square of dark chocolate for dessert? Tell us in the comments below!

See what other Food52 readers are saying.

  • BerryBaby
  • ErinM724
  • PHIL
  • Matt
  • Megan Giller
    Megan Giller
Megan Giller

Written by: Megan Giller


BerryBaby August 19, 2017
I eat dark chocolate everyday and enjoy it whether it does anything or not, it's a great treat!
ErinM724 August 16, 2017
I am one of those weirdos who can be totally satisfied with a 1 in x 1 in square of chocolate. Or whatever size those Ghirardelli squares are.
PHIL August 16, 2017
I only eat one square of chocolate a day, a 12" x 12" square.
BerryBaby August 19, 2017
That's funny, Phil!
Matt August 16, 2017
This is not a well written article. If you wanted to reference that studies involving chocolate are "bunk" you should have chosen a different article.


The article itself tells us that they actually found that there was no significant different between the white chocolate control, dark chocolate, and baseline; and says that more work is needed to see if there is evidence to support the claim that chocolate increases cardio vascular performance. Yet you inaccurately characterise the article as making claims it does not make because you didn't do journalistic due diligence to check the source material, instead you cited the claims of another non-scientist.

Megan G. August 16, 2017
Thanks for reading, Matt, and I'm sorry to hear you were disappointed with the studies I chose to make my point. Feel free to reach out if you want to talk more: [email protected].