Editor's note: This popular story from the Daily Briefing's archives was republished on Oct. 31, 2023.

In recent years, a growing body of evidence has suggested that the flavanols in cocoa may provide a variety of health benefits – and FDA has finally weighed in on the topic, Allison Aubrey writes for NPR's "Shots."

Evidence suggests cocoa may provide some health benefits

The scientific pursuit to understand how cocoa may impact our health has uncovered several benefits.

"Cocoa contains lots of bioactive compounds called flavanols, which have antioxidant and anti-inflammatory properties," Aubrey writes. "In recent years, studies have shown the flavanols in cocoa can help improve blood flow and lower blood pressure."

However, the most compelling evidence is based on studies of cocoa flavanol supplements and flavanol-rich cocoa – not the regular chocolate used in candy.

For example, in the Cosmos trial, which included over 20,000 men and women aged 60 and older, participants consumed capsules with 500 milligrams of cocoa flavanols every day for several years to determine whether it could help lower the risk of heart disease. Study participants did not know if they were consuming cocoa flavanols or a placebo.

"We did see promising signals for prevention of cardiovascular disease events," said study author JoAnn Manson of Brigham and Women's Hospital. "We actually saw a 27% reduction in cardiovascular disease deaths." Despite these signals, the decrease in heart attacks or strokes among participants taking the supplements was not statistically significant.

But it seems that "scientists have honed in on a particular mechanism that helps explain how chocolate can influence our cardiovascular systems," Aubrey writes. "The bio-active flavanols in cocoa can prompt the production of more nitric oxide, a gas which causes our blood vessels to open up — or dilate."

"Vasodilation seems to be the mechanism for lowering of blood pressure and what appears to be signals for reduction in cardiovascular events," Manson said.

Manson noted that these findings should not be interpreted as a free pass to consume more chocolate, especially candy bars that contain sugar, fat, and calories. "We found in the Women's Health Initiative that eating chocolate several times a week, just regular chocolate candy, did lead to weight gain," Manson said.

FDA allows limited health claims on certain cocoa products

In 2018, Barry Callebaut AG Switzerland, a company that manufactures chocolate and cocoa products, petitioned FDA to permit the use of a health claim on labels, citing the link between the consumption of flavanol-rich cocoa and a decreased risk of cardiovascular disease.

Following an extensive review, FDA in early February issued a response saying it will allow the use of certain limited health claims on products that contain high-flavanol cocoa powder. However, the agency noted that there is not enough evidence to support claims that regular chocolate provides similar benefits.

"Despite dozens of published studies evaluating the links between chocolate and health, the FDA's assessment is that, as of now, the science is still inconclusive," Aubrey writes. "It's pretty clear that the compounds in cocoa are good for us, but we may not get enough of them when we consume highly-processed, sweetened chocolate candy bars."

Commentary

According to Aubrey, FDA's newly approved health claims are "limited and confusing." For example, "Cocoa flavanols in high flavanol cocoa powder may reduce the risk of cardiovascular disease, although the FDA has concluded that there is very limited scientific evidence for this claim."

"How is a consumer going to interpret that?" asked nutrition scientist Christopher Gardner, a professor at Stanford University.

Gardner said it is almost impossible to conduct the kind of study that could prove whether a given amount of chocolate lowers the risk of heart disease. First, scientists would have to recruit thousands of people, half of whom would have to be willing to consume chocolate every day for several years and half of whom would have to be willing to never consume chocolate. "Who would sign up for that?" Gardner asked.

When people ask Gardner if chocolate is healthy, he simple asks, "compared to what?" If the decision is between jelly beans and dark chocolate, then dark chocolate is better because of the flavanols, he noted. "The jelly bean is basically just sugar," Gardner said.

To be eligible to make a health claim, FDA said cocoa products must contain at least 4% of naturally conserved cocoa flavanols. However, these chocolates may be too bitter for many people to enjoy, Aubrey notes.

Ultimately, "chocolate can have lots of unique and interesting flavors, so the aim is to relish it," Aubrey writes. "People need to have some fun and enjoy it," and not focus too much on the evidence for – or against – health claims, Gardner added. (Aubrey, "Shots," NPR, 1/12)