Coffee, tea and dementia risk in US adults
What it found
In two large groups of US adults followed for decades, those who drank more caffeinated coffee or tea were less likely to develop dementia and scored slightly better on cognitive tests.
Decaffeinated coffee showed no such links.
What they found
Studies in people
Caffeinated coffee and dementia
People who drank the most caffeinated coffee had fewer cases of dementia than those who drank the least. The authors report 141 cases per 100 000 person-years in the highest intake group compared with 330 in the lowest.
Subjective cognitive decline
The highest caffeinated coffee drinkers also reported less perceived cognitive decline: 7.8% versus 9.5% in the lowest intake group.
Objective cognitive scores
In the women's group, higher caffeinated coffee intake was linked to a slightly higher average score on a telephone cognitive test. The link to a global cognition score was not statistically significant.
Tea and cognition
Higher tea intake showed similar links to lower dementia risk and better cognitive scores as caffeinated coffee.
Decaffeinated coffee
Decaffeinated coffee was not linked to lower dementia risk or better cognitive performance.
Amount linked to benefit
The strongest links were seen at about 2 to 3 cups of caffeinated coffee or 1 to 2 cups of tea per day.
What the authors conclude
“Greater consumption of caffeinated coffee and tea was associated with lower risk of dementia and modestly better cognitive function, with the most pronounced association at moderate intake levels.”
Also in their conclusions
- They conclude that greater consumption of caffeinated coffee and tea was associated with lower risk of dementia and modestly better cognitive function.
- They note that the most pronounced association was at moderate intake levels.
How it was done
Evidence linking coffee and tea to cognitive health is still inconclusive, and most studies do not separate caffeinated from decaffeinated coffee.
They followed 86 606 women from the Nurses' Health Study (from 1980 to 2023) and 45 215 men from the Health Professionals Follow-up Study (from 1986 to 2023) who did not have cancer, Parkinson disease, or dementia at the start. Food questionnaires were filled in every 2 to 4 years, and dementia cases were identified from death records and doctor diagnoses.
What it can’t tell you
- We summarised it from the abstract only.
- This kind of study follows people over time, so it can show a link but cannot prove that coffee or tea directly causes the difference in dementia risk.
- It cannot rule out that other habits or traits of people who drink more coffee or tea explain the findings.
Who paid
- Funding
- Funded by NIDDK NIH HHS; NINR NIH HHS (from the PubMed record).
- Conflicts
- Conflict of Interest Disclosures: Dr Hu reported receiving research support from the Analysis Group. No other disclosures were reported.
- Authors work at
- Harvard University, Massachusetts; Broad Institute, Massachusetts
The paper
- Title
- Coffee and Tea Intake, Dementia Risk, and Cognitive Function
- Type
- Study
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Zhang Y, Liu Y, Li Y, et al (2026). Coffee and Tea Intake, Dementia Risk, and Cognitive Function. JAMA. doi:10.1001/jama.2025.27259Free full textPubMed 41661604DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error