The Study
Coffee and Tea Intake, Dementia Risk, and Cognitive Function.
This study found that people who drank more coffee or tea tended to have less memory problems later in life, but it didn't prove that coffee or tea caused the improvement. It's like noticing that kids who eat more apples also tend to be healthier — but maybe they just exercise more or sleep better too.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
People who drank moderate amounts of caffeinated coffee or tea over many years were less likely to develop memory problems or dementia.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 559 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — a 18% lower risk means about 18 fewer cases of dementia per 100 people over decades, which is meaningful for public health.
- 2People who drank 2–3 cups of caffeinated coffee a day had 18% lower dementia risk.
- 3Those who drank 1–2 cups of tea a day had similar benefits.
- 4Decaf coffee didn’t help.
- 5Coffee drinkers also scored slightly better on memory tests.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
JAMA
Year
2026
Authors
Yu Zhang, Yuxi Liu, Yanping Li, Yuhan Li, Xiao Gu, Jae Hee Kang, A. Eliassen, Molin Wang, E. Rimm, Walter C. Willett, Frank B. Hu, M. Stampfer, Dong Wang
Related Content
Claims (10)
People who drink about 2 to 3 cups of caffeinated coffee daily have an 18% lower risk of developing dementia over 36 or more years compared to those who drink less, based on long-term data from large adult populations.
People who drink 1 to 2 cups of tea daily have a similar level of reduced dementia risk and less subjective cognitive decline as people who drink caffeinated coffee, based on long-term data from over 130,000 individuals in the United States.
People who drink about 2 to 3 cups of caffeinated coffee per day have an 18% lower risk of developing dementia over 36 or more years compared to those who drink less.
Drinking decaffeinated coffee does not lower the risk of dementia or improve thinking skills in middle-aged and older adults.
Older adults who drink more caffeinated coffee show slightly better scores on cognitive tests measuring memory and thinking skills, but there is no clear link to overall cognitive function.
Drinking decaffeinated coffee does not lower the risk of dementia or improve thinking skills in middle-aged and older adults.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.