In a new study from the COcoa Supplement and Multivitamin Outcomes Study (COSMOS), investigators from Mass General Brigham and their colleagues looked at changes in five age-related markers of inflammation among participants who received daily cocoa supplements over several years.

They found that hsCRP an inflammatory marker that can signal increased risk of cardiovascular disease decreased in participants taking the cocoa extract supplement, suggesting its anti-inflammatory potential may help explain its heart-protective effects.

Their results are published in Age and Ageing.

Nutritional interventions have become an increasingly attractive solution for slowing inflammatory aging, so-called "inflammaging." Cocoa extract has been shown in previous, smaller studies to reduce inflammatory biomarkers, thanks to flavanols small, bioactive compounds found not only in the cocoa bean but also berries, grapes, tea, and other plant-based foods.

To bridge the gap between these studies and humans, researchers launched the large-scale COSMOS trial, which examines the effects of cocoa extract on cardiovascular disease, and whether inflammaging may explain those effects.

"Our interest in cocoa extract and inflammaging started on the basis of cocoa-related reductions in cardiovascular disease," said corresponding author Howard Sesso, ScD, MPH, associate director of the Division of Preventive Medicine and associate epidemiologist at Brigham and Women's Hospital.

"We also appreciate the important overlap between healthy aging and cardiovascular health, where aging-related inflammation can harden arteries and lead to cardiovascular disease. Because of that, we wanted to see whether multi-year cocoa extract supplementation versus a placebo could modulate inflammaging and the data suggests it does."

Between 2014 and 2020, Brigham and Women's Hospital led the COSMOS trial, a large-scale, randomized, double-blind, placebo-controlled clinical trial with 21,442 participants over 60 years old, finding that cocoa extract supplementation decreased cardiovascular disease mortality by 27%.

In this new study, researchers collected and analyzed blood samples of 598 COSMOS participants to measure several inflammaging biomarkers: three pro-inflammatory proteins (hsCRP, IL-6, and TNF-α), one anti-inflammatory protein (IL-10), and one immune-mediating protein (IFN-γ).

Comparing changes in these biomarkers measured at baseline, one, and two years follow-up, hsCRP levels decreased by 8.4% each year compared with placebo, while the other biomarkers remained relatively consistent or increased modestly.

The decrease in hsCRP may help explain the cardio-protective effects seen with cocoa extract supplement in the larger COSMOS trial, where participants experienced a reduction in cardiovascular disease death.

Researchers said that changes in the other inflammaging markers, including a small reduction in IL-6 observed in female but not male participants, warrant additional study.

The team will continue to evaluate the COSMOS trial to determine whether the cocoa and multivitamin regimens can curb more severe inflammaging, as well as other important aging-related health outcomes.

"This study calls for more attention to the advantage of plant-based foods for cardiovascular health, including cocoa products rich in flavanols," added Sesso. "It reinforces the importance of a diverse, colorful, plant-based diet especially in the context of inflammation."

Source: https://medicalxpress.com/news/2025-09-cocoa-supplement-key-marker-inflammation.html