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Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies
Anstey KJ, Cherbuin N, Budge M, Young J.. Obesity reviews : an official journal of the International Association for the Study of Obesity, 2011-02-23
Topic: Risk, prevention and care in population studies
Plain-language summary
The relationship between body mass index (BMI) (in midlife and late-life) and dementia was investigated in meta-analyses of 16 articles reporting on 15 prospective studies. Follow-ups ranged from 3.2 to 36.0 years. Meta-analyses were conducted on samples including 25 624 participants evaluated for Alzheimer's disease (AD), 15 435 participants evaluated for vascular dementia (VaD) and 30 470 followed for any type of dementia (Any Dementia). Low BMI in midlife was associated with 1.96 [95% confidence interval (CI): 1.32, 2.92] times the risk of developing AD. The pooled relative risks for AD, VaD and Any Dementia for overweight BMI in midlife compared with normal BMI were 1.35 (95% CI:1.19, 1.54), 1.33 (95% CI: 1.02, 1.75) and 1.26 (95% CI: 1.10, 1.44), respectively. The pooled relative risks of AD and Any Dementia for obese BMI in midlife compared to normal BMI were 2.04 (95% CI: 1.59, 2.62) and 1.64 (95% CI: 1.34, 2.00), respectively. Continuous BMI in late-life was not associated with dementia. Small numbers of studies included in pooled analyses reduce generalizability of findings, and emphasize the need for publication of additional findings. We conclude that underweight, overweight and obesity in midlife increase dementia risk. Further research evaluating late-life BMI and dementia is required.
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APA 7th
Anstey, K. J., Cherbuin, N., Budge, M., & Young, J. (2011). Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies. Obesity reviews : an official journal of the International Association for the Study of Obesity. https://doi.org/10.1111/j.1467-789x.2010.00825.x
Vancouver
Anstey KJ, Cherbuin N, Budge M, Young J. Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies. Obesity reviews : an official journal of the International Association for the Study of Obesity. 2011. doi:10.1111/j.1467-789x.2010.00825.x. PMID: 21348917.
BibTeX
@article{anstey2011-21348917,
author = {Anstey, K. J. and Cherbuin, N. and Budge, M. and Young, J.},
title = {{Body mass index in midlife and late-life as a risk factor for dementia: a meta-analysis of prospective studies}},
journal = {Obesity reviews : an official journal of the International Association for the Study of Obesity},
year = {2011},
doi = {10.1111/j.1467-789x.2010.00825.x},
pmid = {21348917},
url = {https://doi.org/10.1111/j.1467-789x.2010.00825.x}
}
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.
Key findings
- Low BMI in midlife was associated with 1.96 [95% confidence interval (CI): 1.32, 2.92] times the risk of developing AD.
- The pooled relative risks for AD, VaD and Any Dementia for overweight BMI in midlife compared with normal BMI were 1.35 (95% CI:1.19, 1.54), 1.33 (95% CI: 1.02, 1.75) and 1.26 (95% CI: 1.10, 1.44), respectively.
- The pooled relative risks of AD and Any Dementia for obese BMI in midlife compared to normal BMI were 2.04 (95% CI: 1.59, 2.62) and 1.64 (95% CI: 1.34, 2.00), respectively.
- Continuous BMI in late-life was not associated with dementia.
- We conclude that underweight, overweight and obesity in midlife increase dementia risk.
Why it matters
Pooling 15 prospective studies (about 15,000–30,000 people per outcome, followed for 3 to 36 years), this meta-analysis found that people who were obese in midlife had about twice the risk of Alzheimer's disease as people of normal weight (relative risk 2.04), and those who were overweight about 1.35 times the risk. Being underweight in midlife was also linked to higher Alzheimer's risk (1.96), while BMI measured in late life was not associated with dementia. These are associations from observational studies, not proof that changing weight changes risk, and the authors note that the small number of studies in each pooled analysis limits how far the findings generalise.
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Study details
- Study designmeta-analysis
- Participants624
- Evidence strengthHigh
How this study scored 72/100
Published in a peer-reviewed journal, and it is a meta-analysis pooling many studies. 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 69 of the 96 points we could judge it on, which is 72 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Obesity reviews : an official journal of the International Association for the Study of Obesity) |
| Journal's citation record | 3 / 4 | Obesity Reviews: journal h-index 262 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A meta-analysis pooling many studies |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2011 — within 20 year(s) of the newest study here |
| Sample size | 2 / 4 | 624 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) |
| Randomized / blinded | 0 / 2 | A review of other studies — randomization is not credited here |
| Times cited | 6 / 7 | Cited 856 times (OpenAlex, 2026-10-10) |
| Citations per year | 5 / 5 | 50.4 citations a year over 17 year(s) since 2011 |
| Impact for its field and year | 5 / 6 | Cited 25.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 4 / 6 | Cited by 50 other studies in this library |
| Still being cited | 3 / 4 | Cited 150 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | 1 / 3 | Australian National University: institution h-index 1,088 (OpenAlex) |
| Multicenter 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 21348917) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 69 / 96 | Scored on 19 of 20 parts. We have no data for the rest, so they are left out: 69 of the 96 points we could judge it on is 72 out of 100. |
| Total | 72 / 100 | — |
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