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Ginkgo biloba for prevention of dementia: a randomized controlled trial
DeKosky ST, Williamson JD, Fitzpatrick AL, Kronmal RA, Ives DG, Saxton JA, Lopez OL, Burke G et al.. JAMA, 2008-11-01
Topic: Risk, prevention and care in population studies
Plain-language summary
Context Ginkgo biloba is widely used for its potential effects on memory and cognition. To date, adequately powered clinical trials testing the effect of G. biloba on dementia incidence are lacking. Objective To determine effectiveness of G. biloba vs placebo in reducing the incidence of all-cause dementia and Alzheimer disease (AD) in elderly individuals with normal cognition and those with mild cognitive impairment (MCI). Design, setting, and participants Randomized, double-blind, placebo-controlled clinical trial conducted in 5 academic medical centers in the United States between 2000 and 2008 with a median follow-up of 6.1 years. Three thousand sixty-nine community volunteers aged 75 years or older with normal cognition (n = 2587) or MCI (n = 482) at study entry were assessed every 6 months for incident dementia. Intervention Twice-daily dose of 120-mg extract of G. biloba (n = 1545) or placebo (n = 1524). Main outcome measures Incident dementia and AD determined by expert panel consensus. Results Five hundred twenty-three individuals developed dementia (246 receiving placebo and 277 receiving G. biloba) with 92% of the dementia cases classified as possible or probable AD, or AD with evidence of vascular disease of the brain. Rates of dropout and loss to follow-up were low (6.3%), and the adverse effect profiles were similar for both groups. The overall dementia rate was 3.3 per 100 person-years in participants assigned to G. biloba and 2.9 per 100 person-years in the placebo group. The hazard ratio (HR) for G. biloba compared with placebo for all-cause dementia was 1.12 (95% confidence interval [CI], 0.94-1.33; P = .21) and for AD, 1.16 (95% CI, 0.97-1.39; P = .11). G. biloba also had no effect on the rate of progression to dementia in participants with MCI (HR, 1.13; 95% CI, 0.85-1.50; P = .39). Conclusions In this study, G. biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI. Trial Registration clinicaltrials.gov Identifier: NCT00010803.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
DeKosky, S. T., Williamson, J. D., Fitzpatrick, A. L., Kronmal, R. A., Ives, D. G., Saxton, J. A., et al. (2008). Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. https://doi.org/10.1001/jama.2008.683
Vancouver
DeKosky ST, Williamson JD, Fitzpatrick AL, Kronmal RA, Ives DG, Saxton JA, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008. doi:10.1001/jama.2008.683. PMID: 19017911.
BibTeX
@article{dekosky2008-19017911,
author = {DeKosky, S. T. and Williamson, J. D. and Fitzpatrick, A. L. and Kronmal, R. A. and Ives, D. G. and Saxton, J. A. and Lopez, O. L. and Burke, G. and others},
title = {{Ginkgo biloba for prevention of dementia: a randomized controlled trial}},
journal = {JAMA},
year = {2008},
doi = {10.1001/jama.2008.683},
pmid = {19017911},
url = {https://doi.org/10.1001/jama.2008.683}
}
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Key findings
- Results Five hundred twenty-three individuals developed dementia (246 receiving placebo and 277 receiving G. biloba) with 92% of the dementia cases classified as possible or probable AD, or AD with evidence of vascular disease of the brain.
- The overall dementia rate was 3.3 per 100 person-years in participants assigned to G. biloba and 2.9 per 100 person-years in the placebo group.
- The hazard ratio (HR) for G. biloba compared with placebo for all-cause dementia was 1.12 (95% confidence interval [CI], 0.94-1.33; P = .21) and for AD, 1.16 (95% CI, 0.97-1.39; P = .11).
- Conclusions In this study, G. biloba at 120 mg twice a day was not effective in reducing either the overall incidence rate of dementia or AD incidence in elderly individuals with normal cognition or those with MCI.
Why it matters
In this trial of 3069 community volunteers aged 75 or older, Ginkgo biloba did not reduce the incidence of all-cause dementia or Alzheimer disease compared with placebo. The dementia rate was 3.3 per 100 person-years in the Ginkgo biloba group and 2.9 per 100 person-years in the placebo group.
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Study details
- Participants2,587
- Effect size6.3%
- Evidence strengthHigh
How this study scored 82/100
Published in a top-tier journal, and it is a randomized controlled trial.
| Component | Points | Why |
|---|---|---|
| Journal tier | 10 / 10 | Tier 1 — top-tier general journal (JAMA) |
| Journal's citation record | 4 / 4 | JAMA: journal h-index 1,011 (OpenAlex, 2026-10-29) |
| Study design | 11 / 12 | A randomized controlled trial (from PubMed type “Randomized Controlled Trial”) |
| 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 | 2008 — within 20 year(s) of the newest study here |
| Sample size | 3 / 4 | 2,587 participants |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomized / blinded | 2 / 2 | Randomized and blinded or placebo-controlled (as stated in the record) |
| Times cited | 6 / 7 | Cited 671 times (OpenAlex, 2026-10-10) |
| Citations per year | 4 / 5 | 33.5 citations a year over 20 year(s) since 2008 |
| Impact for its field and year | 6 / 6 | Cited 152.1× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 23 other studies in this library |
| Still being cited | 3 / 4 | Cited 70 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Steven T. DeKosky: h-index 132 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Pittsburgh: institution h-index 1,470 (OpenAlex) |
| Multicenter collaboration | 2 / 3 | PubMed indexes it as a multicentre study |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 19017911) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 82 / 100 | — |
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