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Show 1307: Cocoa Compounds and the COSMOS Trial (Archive)

A rigorously conducted, multi-year experiment with cocoa compounds vs placebo showed that they may reduce cardiovascular mortality.
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Cocoa Compounds and the COSMOS Trial (Archive)

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This week on our nationally syndicated radio show, we explore the power of cocoa compounds to help heart health. Our first guest is Harvard’s Dr. JoAnn Manson, lead investigator of the COSMOS trial. That stands for Cocoa Supplement and Multivitamin Outcomes Study. This very large, randomized placebo-controlled study looked at the effects of a multivitamin or cocoa extract on cancer or cardiovascular health.

What Did COSMOS Reveal About Cocoa Compounds?

This double-blind study with more than 20,000 participants had four arms. One-fourth of the volunteers took a placebo multivitamin and placebo cocoa extract pills for three and a half years. Another quarter of the volunteers took active pills, both multivitamin and cocoa compounds. In addition, one quarter got a real multivitamin and placebo cocoa capsules, while the remainder got real cocoa compounds and a placebo multivitamin. Of course, the scientists carefully tallied every cardiovascular event, from angina to death by heart attack. They also scoured the participants’ medical records and self-reports for evidence of new cancer diagnoses.

People who took actual cocoa compounds had 10 percent fewer cardiovascular events than those taking placebo. Given the very large number of participants, that difference was not statistically significant.

The mortality statistics were more interesting, however. People taking cocoa compounds were 27 percent less likely to die from a heart attack or stroke than those taking the dummy capsules. That difference was significant. Nonetheless, this was a secondary outcome, so the researchers are cautious about proclaiming that it is a clear benefit of consuming cocoa compounds.

Did Multivitamins Help?

The scientists had hypothesized that multivitamins might reduce the risk of cancer. However, there were no significant differences in rates of cancer diagnosis between multivitamin and placebo recipients. The exception is lung cancer, which was less frequent among multivitamin users than among those taking placebo vitamin tablets.

How Could Cocoa Compounds Protect the Cardiovascular System?

For years, scientists have known that cocoa flavanols can help the blood vessels relax, allowing them to expand their diameter. This in turn lowers blood pressure modestly but consistently. At a population level, this could have a beneficial effect. Dr. Manson and her colleagues are planning future studies to confirm and extend the findings from COSMOS.

What Supplements Might You Take?

Many health care professionals dismiss dietary supplements as useless. Dr. Manson suggested that might be due in part to the fact that there are no agencies ensuring the quality of dietary supplements. In fact, some studies have shown unacceptable variation in dose or content of certain supplements. Consequently, we asked her how we might be able to get the benefits of these supplements at home. People in the COSMOS trial on the active multivitamin were taking Centrum Silver, a commercially available supplement for people over 50. Those taking the cocoa extract were on a formulation made by Mars, very similar to the CocoaVia Cardio Health product, with 500 mg of cocoa flavanols. Both supplements were very safe.

Our Disclosure:

CocoaVia supports The People’s Pharmacy radio show and podcast, as it has for a long time. The company had no influence on our interview with Dr. Manson.

Chocolate and Cocoa Compounds:

Cacao is the source of both cocoa compounds and of chocolate. So does chocolate contain healthful chemicals? We speak with Dr. Joe Vinson about polyphenols found in foods such as grapes, coffee, tea or cranberries. Dr. Vinson describes some important differences in cacao use. Indigenous peoples of the Americas domesticated the plant and consumed it as a bitter beverage. When Europeans adopted it, they added sugar and started eating it in solid chocolate form.

We learn how to choose chocolate that is likely to have good polyphenol content and we discuss the range of health benefits they may offer. Look for a high-quality cocoa that is not Dutch processed (aka alkali processed), because the alkali can damage flavonoids. Starting with plain cocoa powder rather than a drink mix allows you to control how much and what kind of sweetener you use as well as whether you use milk, water or a milk substitute such as almond milk to make the cocoa you prefer for daily quaffing.

This Week’s Guests:

JoAnn E. Manson, MD, DrPH, MACP, is Chief of the Division of Preventive Medicine at Brigham and Women’s Hospital. She is Professor of Medicine and the Michael and Lee Bell Professor of Women’s Health at Harvard Medical School. You can read the report on cocoa flavanol supplementation here.

The website is https://cosmostrial.org/

Dr. JoAnn Manson led the COSMOS trial to study cocoa compounds

Joe Vinson, PhD, is an emeritus professor of chemistry at the University of Scranton. He is best known for his work with chocolate, tea, coffee, grape juice, cranberry juice, popcorn, and marijuana. His current research interests include the effect of foods, vitamins, and antioxidants on nutrition and health. Dr. Vinson is an Editor for Foods journal, and is a reviewer for multiple journals.

Listen to the Podcast:

The podcast of this program will be available Monday, April 10, 2023, after broadcast on April 8. You can stream the show from this site and download the podcast for free.

Download the mp3

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About the Author
Terry Graedon, PhD, is a medical anthropologist and co-host of The People’s Pharmacy radio show, co-author of The People’s Pharmacy syndicated newspaper columns and numerous books, and co-founder of The People’s Pharmacy website. Terry taught in the Duke University School of Nursing and was an adjunct assistant professor in the Department of Anthropology. She is a Fellow of the Society of Applied Anthropology. Terry is one of the country's leading authorities on the science behind folk remedies..
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  • Sesso HD et al, "Effect of cocoa flavanol supplementation for the prevention of cardiovascular disease events: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial." American Journal of Clinical Nutrition, June 7.2022. DOI: 10.1093/ajcn/nqac055
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