Cocoa extract may slow aging process in older adults, study finds

A large sub-study of the COSMOS trial found that cocoa extract could help slow the rise of inflammation in older adults. In a two-year trial, nearly 600 participants with an average age of about 70 were randomized to receive 500 milligrams of cocoa extract daily or a placebo. Those taking the cocoa supplements experienced an 8.4% slower annual increase in high-sensitivity C-reactive protein, or hsCRP, a widely used blood marker of systemic inflammation, compared with the placebo group.

The findings, published in the British journal Age and Ageing this month, come from the Cocoa Supplement and Multivitamin Outcomes Study, or COSMOS. COSMOS is among the largest clinical investigations into cocoa flavanols, plant-based compounds believed to have anti-inflammatory properties, with more than 21,000 participants across the broader program. Researchers noted that focusing on a smaller subset allowed for more precise tracking of hsCRP changes over time, though the results may not reflect the full 21,000-person trial population. The cocoa extract capsules used in the sub-study provide a concentrated dose of flavanols without the sugar or fat found in many chocolate products.

Inflammation that persists at low levels is common with aging, a phenomenon sometimes called inflammaging. Over time, this chronic inflammation can contribute to the development of aging-related diseases, including cardiovascular disease. study author Dr. Howard Sesso, an associate epidemiologist at Brigham and Women's Hospital, said the findings help illuminate a potential mechanism by which cocoa flavanols could influence aging processes. “Inflammaging reflects a long process during which several aging-related diseases develop, such as cardiovascular disease,” Sesso told Fox News Digital. “While cocoa extract is not a replacement for a healthy lifestyle, these results are encouraging and highlight its potential role in modulating inflammation as we age.”

Earlier COSMOS analyses had suggested that several years of cocoa flavanol supplementation could significantly reduce cardiovascular disease death by about 27%, a finding that researchers say may be related to the anti-inflammatory effects observed in the new sub-study. Yanbin Dong, Ph.D., senior study author and director of Augusta University’s Georgia Prevention Institute, emphasized that the cocoa capsules offer a concentrated flavanol dose without the added sugars and fats of chocolate bars.

Experts caution that the results should be interpreted as promising but preliminary. Mark Kovacs, Ph.D., an exercise physiologist and longevity expert not involved in the study, said lower hsCRP is encouraging but does not prove that people will experience fewer heart attacks, strokes, hospitalizations, or gains in mobility and independence. He urged that dietary or supplemental strategies targeting inflammation be viewed as additions to, not replacements for, foundational factors such as regular exercise, adequate sleep, stress management and nutrient-rich diets such as the Mediterranean pattern.

The study’s authors also stressed the need for caution in generalizing the results. The trial population predominantly consisted of healthy, older White adults and tested only one specific cocoa extract. They noted that larger and more diverse studies are required to determine whether the hsCRP reduction translates into meaningful health outcomes across different groups. Sesso added that while the results are encouraging, they should not be taken as evidence that cocoa flavanols will guarantee longer life or disease avoidance.

Funding for the study came from the National Institutes of Health, with Mars Edge and Pfizer supplying the study pills and infrastructure. The authors disclosed ties to the companies but said the sponsors had no role in the analysis. The researchers, affiliated with Mass General Brigham in Boston and universities in China and the Harvard T.H. Chan School of Public Health, stressed that more work is needed to confirm benefits in broader populations and to determine how cocoa flavanols fit into an overall healthy-aging strategy.

Overall, the new findings add to a growing body of evidence suggesting that cocoa-derived compounds could play a role in modulating aging-related inflammation. They align with broader recommendations to pursue a diverse, colorful diet rich in flavonoids from a range of plant-based foods. Whether these inflammatory markers will be linked to tangible improvements in longevity or incident cardiovascular events remains the subject of ongoing research, and experts agree that cocoa products should complement—not replace—healthy lifestyle choices.