Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Randomized Controlled Trial
. 2023 Dec 1;46(12):2278-2284.
doi: 10.2337/dc23-1012.

Cocoa Extract Supplementation and Risk of Type 2 Diabetes: The Cocoa Supplement and Multivitamin Outcomes Study (COSMOS) Randomized Clinical Trial

Jie Li  1   2 , Howard D Sesso  3   4 , Eunjung Kim  3 , JoAnn E Manson  3   4 , Georgina Friedenberg  3 , Allison Clar  3 , Trisha Copeland  3 , Aladdin H Shadyab  5 , Jean Wactawski-Wende  6 , Lesley Tinker  7 , Simin Liu  1   2   8
Affiliations
Randomized Controlled Trial

Cocoa Extract Supplementation and Risk of Type 2 Diabetes: The Cocoa Supplement and Multivitamin Outcomes Study (COSMOS) Randomized Clinical Trial

Jie Li et al. Diabetes Care. .

Abstract

Objective: Observational studies have indicated that cocoa flavanol supplementation may be a promising strategy for type 2 diabetes (T2D) prevention. We aimed to directly evaluate its clinical efficacy in a large randomized clinical trial (RCT).

Research design and method: The Cocoa Supplement and Multivitamin Outcomes Study (COMSOS) was a 2 × 2 factorial RCT performed from June 2015 to December 2020 that tested cocoa extract and a multivitamin for the prevention of cardiovascular disease (CVD) and cancer. A total of 21,442 U.S. adults free of CVD and recent cancer, including 12,666 women aged ≥65 years and 8,776 men aged ≥60 years, were randomly assigned to receive cocoa extract [500 mg/day cocoa flavanols, including 80 mg (-)-epicatechin] or placebo. In this study, we included 18,381 participants without diabetes at enrollment and examined the effect of cocoa extract supplementation on incident self-reported T2D in intention-to-treat analyses.

Results: During a median follow-up of 3.5 years, 801 incident T2D cases were reported. Compared with placebo, taking a cocoa extract supplement did not reduce T2D (adjusted hazard ratio 1.04, 95% CI 0.91-1.20, P = 0.58). Stratification analyses showed that the effect of cocoa extract supplementation was not significantly modified by sex, race, BMI, smoking, physical activity, dietary quality, flavanol status at baseline, or randomized multivitamin assignment.

Conclusions: Middle-aged and older adults taking a cocoa extract supplement for a median of 3.5 years did not reduce their risk of incident T2D. Further studies of cocoa extract supplementation beginning earlier in adulthood and in populations with different background diets are warranted.

PubMed Disclaimer

Conflict of interest statement

Duality of Interest. S.L. reported receiving consulting fees, payment, or honoraria for lectures and presentations from Barilla, TwinHealth, Johns Hopkins University, Fred Hutchinson Cancer Center, Harvard University, University at Buffalo, Guangdong Provincial People’s Hospital, Fuwai Hospital, Chinese Academy of Medical Sciences, National Institutes of Health, and American Society for Nutrition and participates on data safety monitoring boards for the Semaglutide Effects on Cardiovascular Outcomes in People With Overweight or Obesity (SELECT) trial sponsored by Novo Nordisk and a trial of pulmonary hypertension in patients with diabetes sponsored by Massachusetts General Hospital. H.D.S. and J.E.M. reported receiving investigator-initiated grants from Mars Edge and Pfizer Consumer Healthcare, now Haleon. H.D.S. additionally reported receiving investigator-initiated grants from Pure Encapsulations and Pfizer Inc. and honoraria and/or travel expenses for lectures from the Council for Responsible Nutrition, BASF, National Institutes of Health, and American Society of Nutrition during the conduct of the study. No other conflicts of interest relevant to this article were reported.

Figures

None
Graphical abstract
Figure 1
Figure 1
Cumulative incidence of T2D in cocoa extract supplementation and placebo groups during the trial period. The HR of T2D was calculated by using Cox proportional hazards regression models with adjustment for sex, age, race/ethnicity, randomized multivitamin assignment, education, smoking, alcohol intake, physical activity, dietary quality, family history of diabetes, and BMI (intention-to-treat analysis).
See this image and copyright information in PMC

References

    1. Tinajero MG, Malik VS. An update on the epidemiology of type 2 diabetes: a global Perspective. Endocrinol Metab Clin North Am 2021;50:337–355 - PubMed
    1. Dillinger TL, Barriga P, Escárcega S, Jimenez M, Salazar Lowe D, Grivetti LE. Food of the gods: cure for humanity? A cultural history of the medicinal and ritual use of chocolate. J Nutr 2000;130(Suppl.):2057S–2072S - PubMed
    1. Greenberg JA. Chocolate intake and diabetes risk. Clin Nutr 2015;34:129–133 - PubMed
    1. Oba S, Nagata C, Nakamura K, et al. . Consumption of coffee, green tea, oolong tea, black tea, chocolate snacks and the caffeine content in relation to risk of diabetes in Japanese men and women. Br J Nutr 2010;103:453–459 - PubMed
    1. Matsumoto C, Petrone AB, Sesso HD, Gaziano JM, Djoussé L. Chocolate consumption and risk of diabetes mellitus in the Physicians’ Health Study. Am J Clin Nutr 2015;101:362–367 - PMC - PubMed

Publication types