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Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence
Hamer M, Chida Y.. Psychological medicine, 2008-06-23
Topic: Risk, prevention and care in population studies
Background The association between physical activity and risk of neurodegenerative diseases is not well established. We therefore aimed to quantify this association using meta-analytical techniques. Method We searched Medline, the Cochrane Database of Systematic Reviews and Web of Science databases from 1990 to 2007 for prospective epidemiological studies of physical activity and incident dementia, Alzheimer's and Parkinson's disease. We excluded studies of physical activity and cognitive decline without diagnosis of a neurodegenerative disease. Information on study design, participant characteristics, measurement of exposure and outcome variables, adjustment for potential confounding, and estimates of associations was abstracted independently by the two investigators. Results We included 16 prospective studies in the overall analysis, which incorporated 163797 non-demented participants at baseline with 3,219 cases at follow-up. We calculated pooled relative risk (RR) using a random effects model. The RR of dementia in the highest physical activity category compared with the lowest was 0.72 [95% confidence interval (CI) 0.60-0.86, p Conclusions Our results suggest that physical activity is inversely associated with risk of dementia. Future studies should examine the optimal dose of physical activity to induce protection, which presently remains unclear.
Key findings
- Results We included 16 prospective studies in the overall analysis, which incorporated 163797 non-demented participants at baseline with 3,219 cases at follow-up.
- The RR of dementia in the highest physical activity category compared with the lowest was 0.72 [95% confidence interval (CI) 0.60-0.86, p Conclusions Our results suggest that physical activity is inversely associated with risk of dementia.
Why it matters
Pooling 16 prospective studies that followed 163,797 people without dementia, this 2009 review found that people in the highest physical activity category had a lower relative risk of dementia than those in the lowest: RR 0.72 (95% CI 0.60-0.86). The authors conclude only that activity "is inversely associated with risk of dementia". Because the review pools observational studies, it shows an association, not that exercise prevents dementia, and the authors say the "optimal dose … presently remains unclear". This record's text gives no separate result for Alzheimer's disease.
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Study details
- Participants16
- Evidence strengthLow
How this study scored 65/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for effect reported because the record does not state it. We have no data on senior author's track record, so that was left out: it earned 62 of the 96 points we could judge it on, which is 65 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Psychological medicine) |
| Journal's citation record | 3 / 4 | Psychological Medicine: journal h-index 331 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A systematic review of all the studies on the question (from PubMed type “Systematic Review”) |
| Strength of evidence | 1 / 5 | Rated “low” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2009 — within 20 year(s) of the newest study here |
| Sample size | 1 / 4 | 16 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 | A review of other studies — randomisation is not credited here |
| Times cited | 6 / 7 | Cited 986 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 51.9 citations a year over 19 year(s) since 2009 |
| Impact for its field and year | 2 / 6 | Cited 2.7× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 43 other studies in this library |
| Still being cited | 3 / 4 | Cited 161 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | OpenAlex's profile for last-listed author Y Chida holds only 7 work(s), too few to judge a track record — left out of this score |
| Institution's track record | 2 / 3 | University College London: institution h-index 2,029 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 18570697) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 62 / 96 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 62 of the 96 points we could judge it on is 65 out of 100. |
| Total | 65 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
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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
Hamer, M., & Chida, Y. (2009). Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence. Psychological medicine. https://doi.org/10.1017/s0033291708003681
Vancouver
Hamer M, Chida Y. Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence. Psychological medicine. 2009. doi:10.1017/s0033291708003681. PMID: 18570697.
BibTeX
@article{hamer2009-18570697,
author = {Hamer, M. and Chida, Y.},
title = {{Physical activity and risk of neurodegenerative disease: a systematic review of prospective evidence}},
journal = {Psychological medicine},
year = {2009},
doi = {10.1017/s0033291708003681},
pmid = {18570697},
url = {https://doi.org/10.1017/s0033291708003681}
}
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