Moderate coffee consumption of two to four cups a day was linked to a modest reduction in heart failure risk, according to a meta-analysis published in the Journal of Health, Population, and Nutrition on Mar. 24.
The findings are significant as heart failure remains a major cause of hospitalization and death worldwide. The research suggests that dietary choices like moderate coffee drinking could be modifiable factors influencing heart health.
Researchers analyzed data from over 650,000 participants across seven prospective cohort studies. They found that consuming two to four cups daily was associated with a lower risk of developing heart failure compared to those who drank less or more. The greatest benefit appeared at one to two cups per day, with diminishing returns beyond four cups. "Drinking 2 to 4 cups of coffee a day was linked to a modest reduction in heart failure risk in this updated meta-analysis, with the lowest estimated risk at 1 to 2 cups and the strongest message being moderation, not excess," the researchers said.
The analysis included studies from Sweden, Finland, the United Kingdom, and the United States over up to 35 years of follow-up. Both caffeinated and decaffeinated coffee showed similar protective associations against heart failure. Researchers noted that compounds other than caffeine—such as chlorogenic acids and polyphenols—may contribute beneficial effects.
Despite these findings, researchers rated the overall certainty of evidence as low due to potential confounding factors and variability among populations studied. They recommended further large-scale studies for confirmation: "However, low certainty of evidence and potential residual confounding call for cautious interpretation." The team also suggested future research should examine different types of coffee preparation methods and track changes in intake over time.
Guidance from European authorities considers up to 400 mg caffeine per day safe for most adults—a level broadly consistent with observed benefits in this analysis—but direct testing for specific caffeine thresholds was not conducted.
