Your morning cup o’ Joe can do more than wake you up: A new long-term study issued in JAMA finds higher intake of caffeinated coffee and tea is linked with a reduced risk of dementia and sharpened cognitive function.Why It’s Relevant
Alzheimer’s disease currently affects more than 6 million people in the United States—and that number is projected to more than double to 13 million by 2050. With limited and potentially risky treatment options, early prevention is crucial, with many studies pointing to diet and lifestyle as areas to target. Coffee contains bioactive compounds, including caffeine and polyphenols, which may offer neuroprotection by reducing oxidative stress and inflammation.
By the Numbers
- The researchers analyzed dietary data and cognitive assessments from 86,216 women from the Nurse’s Health Study and 45,215 men from the Health Professionals Follow-Up Study who were free of cancer, Parkinson’s disease, or dementia.
- Over 43 years of follow-up, 11,033 participants were newly diagnosed with dementia.
- Individuals with the highest caffeinated coffee intake—a median of 4.5 cups a day for women and 2.5 cups a day for men—had an 18% reduced risk of dementia compared with individuals with the lowest coffee intake (~0 cups a day), as well as a lower prevalence of subjective cognitive decline (7.8% versus 9.5%, respectively).
- In the nurses’ cohort, higher caffeinated coffee intake was also associated with better performance on objective cognitive tests (the health professionals study did not perform these tests).
- Higher intake of tea showed similar neuroprotective associations, whereas decaffeinated coffee intake did not.
- The strongest associations were observed at moderate consumption levels: two to three cups per day of caffeinated coffee or one to two cups per day of tea.
The Other Side
The researchers noted that reverse causation can’t be excluded because early cognitive changes may influence beverage consumption patterns or reduce the accuracy of self-reported dietary intake. Furthermore, each cohort was composed solely of health professionals, which may limit generalizability.
What’s Next
The researchers said their findings pointed to caffeine as the primary neuroprotective element in coffee and tea, though the dietary surveys didn’t capture granular beverage details such as tea type or coffee roast level. “Further research is warranted to elucidate the mechanistic pathways by which caffeinated and decaffeinated coffee influences cognitive health,” the researchers wrote.
Related Information
Source
Yu Zhang, et al. Coffee and tea intake, dementia risk, and cognitive function. JAMA. Published February 9, 2026. doi: 10.1001/jama.2025.27259
(Image: Getty Images/iStock/Nikolay Ponomarenko)
