Study links moderate coffee intake to reduced mortality risk
Researchers from Harvard University have found that drinking three to four cups of coffee daily may lower the risk of death by 20 percent. The analysis, based on data from over 500,000 participants tracked for more than 20 years, was published October 1, 2025, in the Journal of Nutrition. This large-scale study strengthens evidence of coffee's potential health benefits.
The study, led by Dr. Emily Carter at Harvard T.H. Chan School of Public Health, examined health records from the Nurses' Health Study and the Health Professionals Follow-up Study. These cohorts included 237,000 women and 118,000 men, followed from 1980 to 2018. Participants reported their coffee consumption habits biennially, allowing researchers to track long-term patterns.
Key findings indicate that individuals consuming 3-4 cups of coffee per day had a 20% lower risk of all-cause mortality compared to non-drinkers. The benefits were observed across causes of death, including cardiovascular disease and cancer. 'Our findings suggest that moderate coffee intake is associated with a lower risk of death, independent of smoking or other lifestyle factors,' Dr. Carter stated in the release.
Background context reveals mixed prior research on coffee's effects. Earlier studies suggested potential risks like increased anxiety or heart issues, but recent meta-analyses have leaned toward benefits due to antioxidants like chlorogenic acid. This new research resolves some inconsistencies by using a massive dataset and adjusting for confounders such as diet, exercise, and alcohol use.
The timeline of the study spans decades: data collection began in the 1980s, with analysis completed in 2024. Results were peer-reviewed and published on October 1, 2025. While the study shows correlation, not causation, implications include public health recommendations for moderate consumption—up to 400 mg of caffeine daily, or about four cups.
Experts caution that individual responses vary, and those with conditions like acid reflux should consult doctors. 'This doesn't mean drink more coffee if you don't already; it's about balance,' noted co-author Dr. Michael Lopez. The findings could influence dietary guidelines, emphasizing coffee as part of a healthy lifestyle alongside fruits, vegetables, and physical activity.