Pexels photo by Toni Cuenca.
In a comprehensive observational study published in The Journal of Nutrition, researchers from Tufts University’s Friedman School of Nutrition Science and Policy examined the coffee-drinking habits of 46,332 American adults aged 20 and older. The data spanned 1999 to 2018, sourced from nine cycles of the National Health and Nutrition Examination Survey (NHANES), a program run by the U.S. government to assess health and dietary patterns across the population¹.
The researchers linked this data to National Death Index mortality records, allowing them to track actual health outcomes over time. Participants were followed for approximately 9 to 11 years, making this one of the most robust long-term analyses of coffee consumption and mortality risk to date².
Key Findings
- Black coffee drinkers had a significantly lower risk of death from all causes:
- Drinking 1 cup per day was associated with a 16% lower risk of all-cause mortality.
- Drinking 2–3 cups per day showed a 17% reduction in mortality risk³.
- Additives matter:
- The health benefits were only observed in those who drank black coffee or coffee with minimal sugar and saturated fat.
- Participants who added more than 2.5 grams of sugar or more than 1 gram of saturated fat per cup saw no mortality benefit compared to non-coffee drinkers⁴.
- Caffeinated vs. Decaf:
- The study focused primarily on caffeinated coffee, as the sample size of habitual decaf drinkers was too small to draw strong conclusions⁵.
Why Might Coffee Help?
Coffee contains bioactive compounds such as polyphenols, antioxidants, and anti-inflammatory agents. These may contribute to improved metabolic health and reduced inflammation, which are linked to lower risks of chronic diseases⁶. However, researchers caution that correlation does not equal causation, the study shows association, not proof of direct benefit⁷.
Limitations
- Self-reported dietary recalls can be prone to error.
- Lifestyle factors (e.g., exercise, smoking, socioeconomic status) may also influence outcomes, even though researchers adjusted for many of these variables⁸.
Expert Commentary
“Coffee is among the most-consumed beverages in the world, and with nearly half of American adults reporting drinking at least one cup per day, it’s important for us to know what it might mean for health,” said Fang Fang Zhang, senior author and professor at Tufts University⁹
Takeaway
If you’re a coffee lover, this study offers a comforting sip of good news, especially if you take it black. But moderation and simplicity are key. The moment cream and sugar enter the mix, the benefits may evaporate.
Endnotes
- Zhang, F. F., et al. (2023). Coffee consumption and mortality risk: Findings from NHANES 1999–2018. The Journal of Nutrition.
- Ibid.
- Ibid.
- Ibid.
- Ibid.
- O’Keefe, J. H., DiNicolantonio, J. J., & Lavie, C. J. (2018). Coffee for cardioprotection and longevity. Progress in Cardiovascular Diseases, 61(1), 38–42.
- Zhang et al., 2023.
- Ibid.
- Tufts University. (2023, March). Black coffee linked to lower mortality risk. Retrieved from https://nutrition.tufts.edu