Researchers studied whether a cocoa supplement could reduce inflammation in older adults. Over 2 years, nearly 600 people aged 60 and up took either a cocoa extract pill containing 500 mg of cocoa flavanols (a natural compound) or a placebo. The cocoa group showed lower levels of a key inflammation marker in their blood compared to the placebo group. This suggests that cocoa extract might help reduce the chronic inflammation that naturally happens as we age, which could be good for heart health. However, the effect was modest, and more research is needed to understand how this works.

The Quick Take

  • What they studied: Whether taking a cocoa extract supplement daily for 2 years could reduce inflammation markers in the blood of older adults
  • Who participated: 598 healthy older adults (average age 70 years old; about half were women). Participants were from the United States and were randomly assigned to take either cocoa extract or a fake pill
  • Key finding: People taking cocoa extract had about 8% lower levels of a key inflammation marker (hsCRP) compared to those taking placebo. They also had slightly higher levels of a protective immune marker (IFN-γ). These differences were statistically significant but small in real-world terms
  • What it means for you: Cocoa extract may help reduce one type of age-related inflammation, which could support heart health. However, this is one marker in one study—it’s not a cure-all. Talk to your doctor before starting supplements, especially if you take other medications

The Research Details

This was a randomized controlled trial, which is considered one of the strongest types of research. Participants were randomly assigned to receive either a cocoa extract supplement (500 mg of cocoa flavanols daily) or a placebo (fake pill) for 2 years. Neither the participants nor the researchers knew who was getting the real supplement—this is called ‘double-blind’ and helps prevent bias. Blood samples were collected at the start, after 1 year, and after 2 years to measure inflammation markers.

The study measured five different inflammation markers in the blood. Three of these are pro-inflammatory (they promote inflammation): hsCRP, interleukin-6, and tumor necrosis factor-alpha. One is anti-inflammatory (it reduces inflammation): interleukin-10. The last one, interferon-gamma, has multiple roles in the immune system.

This was part of a larger study called COSMOS that looked at multiple health outcomes. This particular analysis focused specifically on inflammation markers in a random sample of 598 participants from the full study.

This research design is important because it helps prove cause-and-effect relationships. By randomly assigning people to groups and using placebos, researchers can be more confident that any differences between groups are due to the cocoa extract and not other factors. The 2-year duration is also valuable because it shows whether effects last over time, not just in the short term

This study has several strengths: it’s a large, well-designed randomized controlled trial published in a reputable journal; it used a double-blind design to reduce bias; it measured multiple inflammation markers; and it followed people for 2 full years. However, the effect sizes were small, and some statistical adjustments were made to account for testing multiple markers. The study only included older adults, so results may not apply to younger people

What the Results Show

The main finding was that cocoa extract significantly reduced hsCRP (a key inflammation marker) by about 8% per year compared to placebo. This difference was statistically significant, meaning it’s unlikely to have happened by chance. However, 8% is a modest reduction in real-world terms.

The cocoa group also showed a 6.8% increase in interferon-gamma (IFN-γ), an immune marker, compared to placebo. This was also statistically significant. Interferon-gamma plays multiple roles in immune function, and the researchers noted that the meaning of this increase needs further study.

These findings are important because hsCRP is considered a marker of chronic inflammation related to aging (called ‘inflammaging’). Reducing this marker may have benefits for heart health and other age-related conditions.

The cocoa extract did not significantly affect the other three inflammation markers studied: interleukin-6, tumor necrosis factor-alpha, or interleukin-10. This suggests that cocoa’s anti-inflammatory effects may be selective—it targets certain pathways but not others. The researchers also noted that the larger COSMOS trial found a 27% reduction in cardiovascular disease deaths in the cocoa group, suggesting that the inflammation reduction may translate to real health benefits

Previous smaller studies suggested that cocoa flavanols have anti-inflammatory properties. This larger, longer study confirms that cocoa extract can reduce at least one key inflammation marker over an extended period. The findings align with the theory that cocoa’s heart-protective effects may work partly through reducing inflammation. However, the modest effect size suggests cocoa is not a standalone solution for inflammation

The study only included older adults (60+ years), so results may not apply to younger people. The reduction in hsCRP, while statistically significant, was modest (8% per year). The study measured only five inflammation markers, so cocoa may affect other markers not tested here. Participants were generally healthy, so results may differ in people with existing health conditions. The study didn’t measure whether these changes actually prevented disease or improved health outcomes directly

The Bottom Line

Based on this evidence, cocoa extract supplementation may modestly help reduce one type of age-related inflammation in older adults. However, this should not replace proven heart-healthy habits like exercise, a balanced diet, and not smoking. If you’re interested in trying cocoa extract, discuss it with your doctor first, especially if you take blood thinners or other medications. The dose used in this study was 500 mg of cocoa flavanols daily (confidence level: moderate)

This research is most relevant to healthy older adults (60+) interested in supporting heart health and reducing inflammation. People with cardiovascular disease risk factors may find this particularly interesting. However, people taking blood thinners, those with caffeine sensitivity, or those with certain health conditions should consult their doctor before starting cocoa supplements. Younger adults should not assume these results apply to them

The study measured changes over 2 years, so realistic expectations are that any benefits would develop gradually over months to years, not weeks. The hsCRP reduction was measured as a yearly change, suggesting ongoing benefit with continued use. However, stopping the supplement would likely reverse the effects

Want to Apply This Research?

  • If you take a cocoa extract supplement, track daily intake (yes/no) and note any changes in energy levels, heart health markers (if you get blood work), or overall wellness on a monthly basis
  • Users could set a daily reminder to take a cocoa extract supplement at the same time each day (if recommended by their doctor) and log it in the app to maintain consistency, similar to tracking other supplements or medications
  • Track supplement adherence monthly and note any changes in cardiovascular health markers (blood pressure, cholesterol levels) during annual check-ups. Use the app to record these values over time to see if there’s a pattern of improvement

This research suggests cocoa extract may help reduce one inflammation marker in older adults, but it is not a treatment or cure for any disease. Cocoa supplements are not regulated by the FDA in the same way as medications. Before starting any supplement, especially if you take medications (particularly blood thinners), have existing health conditions, or are pregnant or breastfeeding, consult with your healthcare provider. This article is for educational purposes and should not replace professional medical advice. Individual results may vary, and supplements work best as part of an overall healthy lifestyle that includes exercise, a balanced diet, and regular medical care.