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Does caffeine intake protect from Alzheimer's disease?
Maia L, de Mendonça A.. European journal of neurology, 2002-07-01
Topic: Amyloid, tau and blood-test diagnosis
Caffeine is the most widely consumed behaviourally active substance in the western world. Neuroprotective effects of caffeine in low doses, chronically administered, have been shown in different experimental models. If caffeine intake could protect against neurodegeneration in Alzheimer's disease (AD), then higher levels of caffeine consumption in normal subjects as compared with AD patients should be detectable in the presumably long period before diagnosis when insidious pathogenic changes are taking place. A case-control study was used: cases were 54 patients with probable AD fulfilling the National Institute of Neurologic and Communicative Disorders and Stroke and the AD and Related Disorders Association criteria, in a Dementia Clinics setting. Controls were 54 accompanying persons, cognitively normal, matched for age (+/-3 years) and sex. Patients with AD had an average daily caffeine intake of 73.9 +/- 97.9 mg during the 20 years that preceded diagnosis of AD, whereas the controls had an average daily caffeine intake of 198.7 +/- 135.7 mg during the corresponding 20 years of their lifetimes (P < 0.001, Wilcoxon signed ranks test). Using a logistic regression model, caffeine exposure during this period was found to be significantly inversely associated with AD (odds ratio=0.40, 95% confidence interval=0.25-0.67), whereas hypertension, diabetes, stroke, head trauma, smoking habits, alcohol consumption, non-steroid anti-inflammatory drugs, vitamin E, gastric disorders, heart disease, education and family history of dementia were not statistically significantly associated with AD. Caffeine intake was associated with a significantly lower risk for AD, independently of other possible confounding variables. These results, if confirmed with future prospective studies, may have a major impact on the prevention of AD.
Key findings
- If caffeine intake could protect against neurodegeneration in Alzheimer's disease (AD), then higher levels of caffeine consumption in normal subjects as compared with AD patients should be detectable in the presumably long period before diagnosis when insidious pathogenic changes are taking place.
- Using a logistic regression model, caffeine exposure during this period was found to be significantly inversely associated with AD (odds ratio=0.40, 95% confidence interval=0.25-0.67), whereas hypertension, diabetes, stroke, head trauma, smoking habits, alcohol consumption, non-steroid anti-inflammatory drugs, vitamin E, gastric disorders, heart disease, education and family history of dementia were not statistically significantly associated with AD.
- Caffeine intake was associated with a significantly lower risk for AD, independently of other possible confounding variables.
- These results, if confirmed with future prospective studies, may have a major impact on the prevention of AD.
Why it matters
In this case-control study, patients with Alzheimer's disease had lower average daily caffeine intake over the 20 years before diagnosis compared with cognitively normal controls, and caffeine exposure was inversely associated with Alzheimer's disease. This is an observational study and cannot prove that caffeine protects against the disease.
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Study details
- Study designcase-control study
- Participants54
- Evidence strengthModerate
How this study scored 55/100
Published in a peer-reviewed journal, and it is a case-control study. Scored zero for effect reported and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (European journal of neurology) |
| Journal's citation record | 2 / 4 | European Journal of Neurology: journal h-index 181 (OpenAlex, 2026-10-29) |
| Study design | 6 / 12 | A case-control study |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2002 — older than 20 years, still counted |
| Sample size | 1 / 4 | 54 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 6 / 7 | Cited 358 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 13.8 citations a year over 26 year(s) since 2002 |
| Impact for its field and year | 3 / 6 | Cited 5.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 4 other studies in this library |
| Still being cited | 2 / 4 | Cited 22 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Alexandre de Mendonça: h-index 65 (OpenAlex, whole career) |
| Institution's track record | 0 / 3 | University of Lisbon: institution h-index 605 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 12099922) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 55 / 100 | — |
What each of these 20 components measures, and what this score is not →
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Maia, L., & de Mendonça, A. (2002). Does caffeine intake protect from Alzheimer's disease? European journal of neurology. https://doi.org/10.1046/j.1468-1331.2002.00421.x
Vancouver
Maia L, de Mendonça A. Does caffeine intake protect from Alzheimer's disease? European journal of neurology. 2002. doi:10.1046/j.1468-1331.2002.00421.x. PMID: 12099922.
BibTeX
@article{maia2002-12099922,
author = {Maia, L. and de Mendonça, A.},
title = {{Does caffeine intake protect from Alzheimer's disease?}},
journal = {European journal of neurology},
year = {2002},
doi = {10.1046/j.1468-1331.2002.00421.x},
pmid = {12099922},
url = {https://doi.org/10.1046/j.1468-1331.2002.00421.x}
}
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