The Study
Tea, coffee, and caffeine intake and risk of dementia and Alzheimer's disease: a systematic review and meta-analysis of cohort studies.
This study looked at lots of people over time and found that those who drank more tea seemed to have a lower chance of getting dementia, but it doesn’t prove tea stops dementia — maybe tea drinkers also exercise more or eat better. It’s like noticing people who wear hats don’t get sunburned — but we don’t know if the hat is what helped.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
Scientists looked at many studies about people who drank tea, coffee, or had caffeine and checked if they got dementia less often.
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 552 / 100
Quality score
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The risk reductions are small and not certain — tea might help a little, but it’s not a strong or guaranteed protection.
- 2People who drank more tea had a 4% lower dementia risk per cup.
- 3The best coffee amount was 1–3 cups a day.
- 4Caffeine didn't clearly lower dementia risk.
- 5Tea drinkers had 7% lower Alzheimer’s risk at highest intake.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Food & function
Year
2024
Authors
Fengjuan Li, Xiaoning Liu, Bin Jiang, Xinying Li, Yanqi Wang, Xiaojuan Chen, Yuhao Su, Xiaojie Wang, Jun Luo, Lifang Chen, Jiangtao Li, Qian Lv, Jian Xiao, Jun Wu, Jianping Ma, Pei Qin
Related Content
Claims (6)
People who drink a moderate amount of coffee or tea may be less likely to develop dementia later in life — about 18% less likely, according to this claim.
People who drink more tea tend to have a slightly lower chance of getting dementia — every extra cup a day might lower the risk by about 4%.
People who drink 1 to 3 cups of coffee a day might have the lowest chance of getting dementia, according to studies of hundreds of thousands of adults — but drinking more or less than that doesn’t seem to help as much.
People who drink a lot of tea may have a slightly lower chance of getting Alzheimer’s disease compared to those who drink little or no tea, according to studies tracking large groups of people over time.
Drinking caffeine doesn’t seem to make you more or less likely to get dementia — people who drink the most caffeine had a tiny bit lower risk, but it’s not enough to be sure it’s real.
Scientists aren’t sure if drinking tea, coffee, or caffeine affects your risk of dementia or Alzheimer’s — the evidence is too weak to say for sure.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.