What Is the Evidence That Cocoa Flavanols Improve Health?

As Valentine’s Day approaches, you will no doubt see a number of feature pieces suggesting that chocolate is actually good for you. These stories may be counterbalanced by others pointing out that chocolate is high in sugar and fat, and therefore also pretty high in calories. Consequently, they say, chocolate is not good for you at all. In truth, though the question is really about the plant compounds in chocolate. Is there real evidence that cocoa flavanols improve health?

Do Cocoa Flavanols Improve Health or Harm It?

Q. As a physician, I’m concerned about the ethics of advertising supplements. Some of these products are touted to support brain and heart health. There is no evidence behind such claims. You’ve said cocoa flavanols improve health, and you should be ashamed of yourselves.

A. There are certainly products being advertised that are not supported by clinical trials. We definitely share your concerns about them. We disagree about cocoa flavanols, however.

When it comes to CocoaVia, the underwriter on our syndicated radio show, there is a substantial body of research. Cocoa flavanols can lower blood pressure modestly (Cochrane Database of Systematic Reviews, April 25, 2017).  They may do this by making blood vessels more flexible (Journal of Agricultural and Food Chemistry, online Aug. 12, 2019).  In addition, cocoa flavanols can reduce markers of inflammation (Frontiers in Immunology, April 24, 2019). 

Cocoa Flavanols and the Brain:

As for cognitive function, researchers have done fewer studies.

However, a systematic review of 12 studies found

“a positive effect of cocoa polyphenols on memory and executive function” (Plant Foods for Human Nutrition, Jan. 13, 2020). 

In addition, Harvard researchers are currently conducting a large placebo-controlled study to see whether cocoa flavanols improve health. The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) has enrolled more than 18,000 older individuals who will take either cocoa flavanols or placebo plus multivitamin or placebo for four years. Beyond cardiovascular outcomes and cancer, the researchers are also collecting information on cognitive function, macular degeneration and cataracts. As the study is still underway, we shall have to wait several years for the scientists to finish collecting and analyzing all the data before we sill know what it can tell us about cocoa flavanols and the aging brain.

Where Can You Find Cocoa Flavanols?

We’ve already mentioned the calories in chocolate candy. The compounds themselves do not provide many calories, but candy certainly can. Moreover, not all chocolate candy is rich in cocoa flavanols. When we are looking for a good source of these compounds, we start with CocoaVia. Yes, they do underwrite our radio show. But they also provide the highest amount of cocoa flavanols per serving (450 mg) with very low levels of the toxic element cadmium. Chocolate really doesn’t come close.

To find other sources, we like to check with ConsumerLab.com. They review cocoa, chocolate and supplements and rank them according to flavanol and cadmium content. Ideally, you want more flavanols and less cadmium. Montezuma’s Dark Chocolate Absolute Black scores well with respect to other dark chocolates. (Milk chocolate doesn’t have enough cocoa flavanols to compete.)