The percentage is the share of dementia cases a model attributes to that factor across a
whole population. It is not your personal risk, and the shares are not meant to be added up.
Hearing loss (midlife)
Modelled estimate
Increases risk
Can be changed
7%
of cases attributed to this factor (modelled)
- RR 1.37 (95% CI 1.00-1.87); a separate larger analysis gives HR 1.35 (95% CI 1.26-1.45)
- Evidence: High
- Sensory
Untreated hearing loss is one of the single largest contributors to dementia risk in the Lancet Commission's model, plausibly via reduced auditory/cognitive stimulation and social withdrawal. Each additional category of hearing-loss severity raised risk by about 16% (95% CI 1.07-1.27) in the cited literature; hearing-aid use appears to partly offset the excess risk.
Table 1 RR 1.4 (95% CI 1.0-1.9), prevalence 59.0%, weighted PAF 7.0% (rounded 7%). Observational; reverse causation (subclinical dementia causing perceived hearing decline) not fully excluded.
Source: Lancet Commission 2024 report (Table 1, new pooled meta-analysis of 6 cohorts, n=666,370) · 2024
High LDL cholesterol (midlife)
Modelled estimate
Increases risk
Can be changed
6.9%
of cases attributed to this factor (modelled)
- RR 1.3 (95% CI 1.3-1.4); n=1,189,090 study of LDL >3 mmol/L, HR 1.33 (95% CI 1.26-1.41); each 1 mmol/L increase in LDL raised risk 8% (95% CI 1.03-1.14)
- Evidence: Moderate
- Cardiovascular
Elevated LDL cholesterol in midlife (not late life) is newly recognized (2024) as a dementia risk factor. Statin use was associated with lower dementia risk (OR 0.80, 95% CI 0.75-0.86) versus untreated high cholesterol in a 36-cohort meta-analysis, though a Cochrane review of late-life statin RCTs found no benefit.
New in the 2024 report. Prevalence estimate (76.5%) is drawn from a single Norwegian cohort (HUNT study, ~37,000 participants aged 45+) because the Commission could not find a worldwide LDL prevalence estimate -- the weakest prevalence input of the 14 factors, per the Commission's own text. Weighted PAF 6.9% (rounded 7%).
Source: Lancet Commission 2024 report (Table 1) · 2024
Social isolation (later life)
Modelled estimate
Increases risk
Can be changed
4.6%
of cases attributed to this factor (modelled)
- RR 1.6 (95% CI 1.3-1.8); systematic review of 8 studies (n=15,762), RR 1.57 (95% CI 1.32-1.85)
- Evidence: Moderate
- Psychosocial
Infrequent social contact in later life raises dementia risk, plausibly through loss of cognitive stimulation and increased stress/inflammation. A related but distinct construct, loneliness, shows RR estimates of 1.26-1.58 across separate reviews.
Prevalence 24.0%, weighted PAF 4.6% (rounded 5%). Studies with under 4 years of follow-up are especially prone to reverse causation (preclinical dementia causing social withdrawal, not the reverse).
Source: Lancet Commission 2024 report (Table 1) · 2024
Less education (early life)
Modelled estimate
Increases risk
Can be changed
4.5%
of cases attributed to this factor (modelled)
- RR 1.6 (95% CI 1.3-2.0)
- Evidence: High
- Other
Fewer years of formal education is linked to higher dementia risk, likely because education builds 'cognitive reserve' -- the brain's capacity to compensate for pathology. A Latin American meta-analysis of 31 studies found dementia prevalence of 21.4% in people with no education versus 9.9% in those with at least one year of schooling.
Weighted PAF 4.5% (rounded 5%); prevalence of low education used in the model was 23.2%. Confounded by socioeconomic status, which the Commission partly adjusts for via its 'communality' weighting.
Source: Lancet Commission on dementia prevention, intervention, and care, 2024 report (Table 1) · 2024
Depression (midlife/later life)
Modelled estimate
Increases risk
Can be changed
3%
of cases attributed to this factor (modelled)
- RR 2.2 (95% CI 1.7-3.0) per Lancet Commission's own meta-analysis; UK Biobank HR 1.51 (95% CI 1.38-1.63)
- Evidence: High
- Psychosocial
Depression at any life stage is associated with raised dementia risk, with the largest relative risk seen for early/midlife-onset depression. Effectively treated depression (UK Biobank) was associated with a lower risk, HR 0.62 (95% CI 0.53-0.73), than untreated depression.
2024 report reclassified depression from 'later life' to 'midlife' category. Table 1 RR 2.2 (95% CI 1.7-3.0), prevalence 7.2%, weighted PAF 3.0% (rounded 3%). Bidirectional relationship: depression can be a prodromal symptom of dementia rather than purely causal.
Source: Lancet Commission 2024 report (Table 1, new meta-analysis of 7 studies) · 2024
Traumatic brain injury (midlife)
Modelled estimate
Increases risk
Can be changed
2.9%
of cases attributed to this factor (modelled)
- RR 1.7 (95% CI 1.4-1.9); meta-analysis of 21 studies (n=8,684,485), OR 1.81 (95% CI 1.53-2.14)
- Evidence: High
- Other
A history of traumatic brain injury, including single mild concussions, measurably raises later dementia risk. Younger age at injury and male sex are associated with higher risk; contact-sport cohorts (e.g., professional soccer players) show elevated neurodegenerative-disease mortality.
Prevalence 12.1%, weighted PAF 2.9% (rounded 3%). TBI risk clusters with other risk behaviors (alcohol use, low education); the effect is attenuated but not eliminated after adjustment for confounders.
Source: Lancet Commission 2024 report (Table 1) · 2024
Air pollution (later life)
Modelled estimate
Increases risk
Can be changed
2.6%
of cases attributed to this factor (modelled)
- RR 1.1 (95% CI 1.1-1.1); US cohort of >18 million, black carbon (PM2.5 constituent) HR 1.12 (95% CI 1.11-1.14) per 1 ug/m3 increment
- Evidence: Moderate
- Environmental
Long-term exposure to particulate air pollution, especially black carbon, raises dementia risk. Quasi-experimental evidence from air-quality improvement policies in France found a 12.2 ug/m3 reduction in PM2.5 was associated with lower dementia risk (HR 0.85, 95% CI 0.76-0.95), supporting a reversible, plausibly causal relationship.
Prevalence 75.0% (i.e., most of the world's population has meaningful exposure), weighted PAF 2.6% (rounded 3%). Individual pollutant components are not fully disentangled and exposure measurement is imprecise.
Source: Lancet Commission 2024 report (Table 1) · 2024
Physical inactivity (midlife/later life)
Modelled estimate
Increases risk
Can be changed
2.4%
of cases attributed to this factor (modelled)
- RR 1.2 (95% CI 1.2-1.3)
- Evidence: Moderate
- Lifestyle
Physical inactivity in midlife/later life raises dementia risk; conversely, maintaining an individually optimal activity level over decades was protective (HR 0.75, 95% CI 0.58-0.97) compared with persistent inactivity in a cohort followed a median 24.5 years. See also the separate 'physical-activity' protective-factor entry.
2024 report reclassified physical inactivity from 'later life' to 'midlife' category. Prevalence 27.5%, weighted PAF 2.4% (rounded 2%). Reverse causation risk: preclinical dementia often reduces activity levels before diagnosis.
Source: Lancet Commission 2024 report (Table 1) · 2024
Smoking (midlife)
Modelled estimate
Increases risk
Can be changed
2.3%
of cases attributed to this factor (modelled)
- RR 1.30 (95% CI 1.18-1.45); UK Biobank HR 1.7 (95% CI 1.2-2.5) for smokers under 50 at baseline
- Evidence: High
- Lifestyle
Current midlife smoking substantially raises dementia risk; former smokers show little to no excess risk, suggesting quitting reduces risk at essentially any age. The 2024 Lancet Commission reclassified smoking from a late-life to a midlife risk factor based on newer evidence.
Table 1 RR 1.3 (95% CI 1.2-1.4), prevalence 22.3%, weighted PAF 2.3% (rounded 2%).
Source: Lancet Commission 2024 report (Table 1); Zhong et al. meta-analysis, 37 studies · 2024
Diabetes (midlife)
Modelled estimate
Increases risk
Can be changed
2.3%
of cases attributed to this factor (modelled)
- RR 1.7 (95% CI 1.6-1.8); each 5-year-earlier age of type-2-diabetes onset raised risk HR 1.24 (95% CI 1.06-1.46) up to age-70 onset
- Evidence: High
- Metabolic
Diabetes diagnosed in midlife substantially raises dementia risk via vascular damage, CNS insulin resistance, and inflammation. The Commission explicitly classifies diabetes as a midlife risk factor and notes its effect is uncertain when onset occurs late in life.
2024 report reclassified diabetes from 'later life' to 'midlife' category. Prevalence 9.3%, weighted PAF 2.3% (rounded 2%). Some glucose-lowering drug classes (SGLT2 inhibitors, GLP-1 agonists) show associated risk reduction in observational data, but causality is unproven.
Source: Lancet Commission 2024 report (Table 1) · 2024
Hypertension (midlife)
Modelled estimate
Increases risk
Can be changed
2.2%
of cases attributed to this factor (modelled)
- HR 1.42 (95% CI 1.15-1.76) for untreated hypertension vs. healthy controls; SPRINT MIND trial: probable-dementia HR 0.83 (95% CI 0.67-1.04, not significant), MCI HR 0.81 (95% CI 0.69-0.95)
- Evidence: Moderate
- Cardiovascular
Midlife hypertension raises dementia risk, and treating it appears protective against cognitive decline and MCI. The flagship SPRINT MIND randomized trial found intensive blood-pressure control significantly reduced MCI but its dementia-specific endpoint narrowly missed statistical significance, likely because the trial was stopped early and underpowered for that outcome.
Table 1 RR 1.2 (95% CI 1.1-1.4), prevalence 31.1%, weighted PAF 2.2% (rounded 2%). Blood pressure trajectories tend to drop shortly before dementia onset, complicating late-life measurement.
Source: Lancet Commission 2024 report (Table 1); Williamson et al., SPRINT MIND, JAMA 2019 · 2019
Untreated vision loss (later life)
Modelled estimate
Increases risk
Can be changed
2.2%
of cases attributed to this factor (modelled)
- RR 1.5 (95% CI 1.4-1.6); meta-analysis of 14 prospective cohorts (n=6,204,827), pooled RR 1.47 (95% CI 1.36-1.60)
- Evidence: Moderate
- Sensory
Vision impairment -- much of it correctable -- was newly added as a dementia risk factor in the Lancet Commission's 2024 report. Cataract surgery specifically was associated with lower subsequent dementia risk (HR 0.71, 95% CI 0.62-0.83) versus unoperated cataracts, suggesting a genuinely modifiable pathway; diabetic retinopathy also raised risk (HR 1.34, 95% CI 1.11-1.61), while glaucoma and age-related macular degeneration showed no significant association.
New in the 2024 report (not in the 2020 list). Prevalence 12.7%, weighted PAF 2.2% (rounded 2%). Global prevalence estimate skews toward low- and middle-income countries where untreated vision loss is more common.
Source: Lancet Commission 2024 report (Table 1) · 2024
Obesity (midlife)
Modelled estimate
Increases risk
Can be changed
1.4%
of cases attributed to this factor (modelled)
- RR 1.31 (95% CI 1.02-1.68), meta-analysis of 14 studies (n=77,890); central obesity (waist circumference) HR 1.10 (95% CI 1.05-1.15)
- Evidence: Moderate
- Metabolic
Midlife obesity raises dementia risk, but the relationship is complicated near the time of diagnosis: obesity measured within about 10 years of dementia onset can appear protective because of pre-diagnostic weight loss (reverse causation).
Table 1 RR 1.3 (95% CI 1.0-1.7), prevalence 13.0%, weighted PAF 1.4% (rounded 1%). Heavily confounded with diabetes, hypertension, and physical inactivity.
Source: Lancet Commission 2024 report (Table 1) · 2024
Excessive alcohol consumption (midlife)
Modelled estimate
Increases risk
Can be changed
1%
of cases attributed to this factor (modelled)
- RR 1.2 (95% CI 1.0-1.5); heavier (>21 UK units/week) vs. lighter drinking, HR 1.22 (95% CI 1.01-1.48), IPD meta-analysis n=131,415
- Evidence: Moderate
- Lifestyle
Heavy/excessive alcohol use in midlife raises dementia risk in a dose-dependent way; a South Korean cohort of nearly 4 million found cutting back from heavy to moderate drinking lowered risk (HR 0.92, 95% CI 0.86-0.99).
Prevalence 13.3%, weighted PAF 1.0% (rounded 1%). 'Non-drinker' comparison groups are often contaminated by former heavy drinkers who quit due to illness, producing a misleading J-shaped risk curve in some studies.
Source: Lancet Commission 2024 report (Table 1) · 2024
APOE4 genotype (dose-dependent)
Basis not stated
Increases risk
- One copy (heterozygous, e3/e4): OR 3.2 (95% CI 2.8-3.8); two copies (homozygous, e4/e4): OR 14.9 (95% CI 10.8-20.6), both vs. e3/e3 reference
- Evidence: High
- Genetic
Carrying one copy of the APOE4 allele roughly triples Alzheimer's odds; carrying two copies (homozygous) raises odds nearly 15-fold relative to the common e3/e3 genotype, a clear gene-dosage effect. The e2/e3 genotype was mildly protective (OR 0.6, 95% CI 0.5-0.8).
Landmark, still most-cited meta-analysis; not included in the Lancet Commission's modifiable-risk PAF model since APOE4 is non-modifiable. Effect size varies substantially by ancestry: stronger in Japanese populations (e4/e4 OR 33.1) and weaker in African American/Hispanic populations in the same meta-analysis.
Source: Farrer LA, Cupples LA, Haines JL, et al., JAMA 1997 (pooled meta-analysis, 40 research teams, 5,930 AD cases, 8,607 controls) · 1997
Family history of Alzheimer's/dementia
Basis not stated
Increases risk
- RR 1.73 (95% CI 1.59-1.87) for 1+ affected first-degree relative; RR 3.98 (95% CI 3.26-4.82) for 2+ affected first-degree relatives
- Evidence: High
- Genetic
Risk climbs steeply with the number of affected close relatives; risk elevation extends even to second- and third-degree relatives, indicating a broad polygenic/inherited contribution beyond APOE4 alone.
Utah-specific founder population (largely European ancestry), which may limit generalizability. The reported RR for 3+ affected first-degree relatives (2.48, 95% CI 1.07-4.89) is numerically lower than for 2+ relatives, an instability the study authors themselves note as likely due to small subgroup size.
Source: Cannon-Albright LA, et al., Neurology 2019 (Utah Population Database, 270,818 individuals, 4,436 AD deaths) · 2019
Age
Modelled estimate
Increases risk
- Prevalence 5.1% (ages 65-74), 13.2% (ages 75-84), 33.4% (ages 85+)
- Evidence: High
- Demographic
Age is the single strongest predictor of Alzheimer's/dementia risk; prevalence increases roughly exponentially after age 65, more than doubling with each successive decade.
Figures shown are modeled prevalence by age band, not a formal per-decade relative risk statistic (a single pooled RR-per-decade figure is rarely reported in this literature), but function as the standard effect-size proxy for age.
Source: Alzheimer's Association, 2025 Alzheimer's Disease Facts and Figures · 2025
Sex (being female)
Basis not stated
Increases risk
- HR 1.12 (95% CI 1.02-1.23), meta-analysis of 21 cohorts (n=29,850); lifetime risk at age 65: women 24.6% vs. men 15.5% (all-cause dementia)
- Evidence: Moderate
- Demographic
Women show meaningfully higher lifetime dementia risk than men in Western cohort data, but the Lancet Commission attributes this substantially to women's greater life expectancy and historically lower educational attainment rather than to a clearly established sex-specific biological mechanism. The Commission's own text notes findings on sex differences are inconsistent across countries.
For Alzheimer's disease specifically (Framingham data), lifetime risk at 65 was 21.1% for women vs. 11.6% for men (p<0.001). Evidence is heterogeneous across countries/study designs.
Source: Lancet Commission 2024 report; Chene G, et al., Alzheimer's & Dementia 2015 (Framingham Heart Study) · 2015
Down syndrome (trisomy 21)
Basis not stated
Increases risk
- Symptomatic Alzheimer's prevalence reaches 90-100% by the seventh decade of life; lifetime risk of AD >90%
- Evidence: High
- Genetic
Trisomy 21 causes near-universal Alzheimer's brain pathology and very high rates of clinical dementia by late-middle-age, because the extra copy of chromosome 21 causes lifelong overexpression of the amyloid precursor protein (APP) gene. Among a cohort of 388 adults with Down syndrome, median age of Alzheimer's-dementia diagnosis was 53.7 years and median age of prodromal-AD diagnosis was 50.2 years.
The strongest known genetic risk factor for early-onset Alzheimer's in people who survive to middle age. Figures reflect people with Down syndrome who survive into adulthood; onset ages are typically decades earlier than late-onset Alzheimer's in the general population.
Source: Fortea J, Vilaplana E, Carmona-Iragui M, et al., The Lancet 2020 · 2020
Mediterranean diet adherence (protective)
Basis not stated
Decreases risk
Can be changed
- HR 0.89 (95% CI 0.83-0.95) for dementia (10 studies); HR 0.70 (95% CI 0.60-0.82) for Alzheimer's disease specifically (9 cohorts)
- Evidence: Moderate
- Lifestyle
Higher adherence to a Mediterranean-style diet is associated with an 11% lower risk of dementia overall and a 30% lower risk of Alzheimer's disease specifically in pooled cohort data spanning 2000-2024.
Purely observational; no large randomized controlled trial has confirmed causality for dementia as a primary endpoint. Residual confounding by socioeconomic status, education, and general healthy-lifestyle clustering is likely.
Source: Meta-analysis of 23 studies, 2000-2024 · 2024
Physical activity (protective)
Basis not stated
Decreases risk
Can be changed
- HR 0.75 (95% CI 0.58-0.97) for maintaining an individually optimal activity level vs. persistent inactivity
- Evidence: Moderate
- Lifestyle
Sustained physical activity across adulthood is associated with roughly a quarter reduction in dementia risk compared with persistent inactivity, in a cohort of 29,826 people followed a median 24.5 years with activity assessed twice a decade apart. This is the protective mirror of the 'physical-inactivity' risk-factor entry.
Same reverse-causation concern as inactivity: declining activity can itself be an early, pre-diagnostic dementia symptom, which may inflate the apparent protective effect of staying active.
Source: Lancet Commission 2024 report (cited cohort study) · 2024
Intensive (systolic <120 mm Hg) vs standard (<140 mm Hg) blood-pressure treatment - SPRINT MIND trial
Basis not stated
No significant effect
Can be changed
- Probable dementia HR 0.83 (95% CI 0.67-1.04), 7.2 vs 8.6 cases per 1,000 person-years (not significant); MCI HR 0.81 (0.69-0.95), 14.6 vs 18.3 per 1,000 person-years; MCI or probable dementia HR 0.85 (0.74-0.97)
- Evidence: High
- Cardiovascular
The only large randomised trial of blood-pressure targets with adjudicated dementia as the primary cognitive outcome found no significant reduction in probable dementia with intensive control, although mild cognitive impairment and the combined MCI-or-dementia outcome were significantly reduced. The trial was stopped early for cardiovascular benefit, so it accrued fewer dementia cases than planned and may have been underpowered for the dementia endpoint.
PMID 30688979; PMC6439590; NCT01206062. 9,361 adults aged >=50 with hypertension, no diabetes or prior stroke, 102 US/Puerto Rico sites; intensive n=4,678, standard n=4,683; mean age 67.9; 35.6% women; 91.5% had >=1 follow-up cognitive assessment; median intervention 3.34 years, median follow-up 5.11 years; 149 vs 176 probable-dementia cases. Recorded as a null primary result with a significant secondary (MCI) result. Complements the observational 'hypertension' record.
Source: SPRINT MIND Investigators for the SPRINT Research Group; Williamson JD, Pajewski NM, Auchus AP, et al. Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial. JAMA 2019;321(6):553-561 · 2019
Low-dose aspirin (100 mg daily) in healthy older adults - ASPREE trial
Basis not stated
No significant effect
Can be changed
- All dementia triggers HR 1.03 (95% CI 0.91-1.17); probable AD HR 0.96 (0.74-1.24); MCI HR 1.12 (0.92-1.37); cognitive change over time similar in both arms
- Evidence: High
- Other
In a large placebo-controlled trial of community-dwelling adults aged 70+ (US minorities 65+) free of cardiovascular disease and dementia, daily low-dose aspirin did not reduce incident dementia, probable Alzheimer's disease, MCI or cognitive decline over a median 4.7 years. Aspirin is therefore not a dementia-prevention strategy in healthy older people.
PMID 32213642; PMC7455352; NCT01038583. 19,114 participants, US and Australia; 964 triggered dementia assessment; 575 adjudicated dementia cases (DSM-IV), 41% clinically probable AD. Class II evidence per the journal's classification. Deliberately recorded as a null finding.
Source: Ryan J, Storey E, Murray AM, et al. Randomized placebo-controlled trial of the effects of aspirin on dementia and cognitive decline. Neurology 2020;95(3):e320-e331 · 2020
Ginkgo biloba extract (120 mg twice daily) - Ginkgo Evaluation of Memory (GEM) trial
Basis not stated
No significant effect
Can be changed
- All-cause dementia HR 1.12 (95% CI 0.94-1.33; P=.21); Alzheimer's disease HR 1.16 (0.97-1.39; P=.11); progression from MCI to dementia HR 1.13 (0.85-1.50; P=.39); dementia rate 3.3 vs 2.9 per 100 person-years (ginkgo vs placebo)
- Evidence: High
- Other
The largest placebo-controlled trial of Ginkgo biloba, in 3,069 community volunteers aged 75+ with normal cognition or MCI followed for a median 6.1 years, found no reduction in all-cause dementia or Alzheimer's disease; point estimates were, if anything, slightly unfavourable. Ginkgo remains widely sold for memory despite this null result.
PMID 19017911; PMC2823569; NCT00010803. 5 US academic centres, 2000-2008; ginkgo n=1,545, placebo n=1,524; 2,587 normal cognition and 482 MCI at entry; 523 incident dementia cases (277 ginkgo, 246 placebo), 92% possible/probable AD or AD with vascular disease; dropout/loss to follow-up 6.3%; similar adverse-event profiles. Null finding recorded deliberately.
Source: DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA 2008;300(19):2253-2262 · 2008
Antioxidant supplements (vitamin E, selenium, or both) - PREADViSE trial in asymptomatic older men
Basis not stated
No significant effect
Can be changed
- Adjusted HR vs placebo: vitamin E 0.88 (95% CI 0.64-1.20); selenium 0.83 (0.60-1.13); combination 1.00 (0.75-1.35); dementia incidence 4.4% overall (325/7,338), not different across arms
- Evidence: Moderate
- Lifestyle
Neither vitamin E nor selenium, alone or together, prevented dementia in 7,540 men aged 60+ enrolled through the SELECT prostate-cancer prevention trial. The randomised phase (2002-2009) converted to an observational cohort after SELECT closed for futility, which weakens the design, but the result is consistently null.
PMID 28319243; PMC5506489. Mean baseline age 67.5 (SD 5.3); 52.2% college-educated; 10.0% Black; 6.7% Hispanic; 130 SELECT sites; 3,786 continued into the cohort phase (Sep 2009-May 2015); modified intent-to-treat Cox models. Men only; dementia ascertained by two-stage screen plus record review, not universal clinical evaluation. Null finding recorded deliberately.
Source: Kryscio RJ, Abner EL, Caban-Holt A, et al. Association of Antioxidant Supplement Use and Dementia in the Prevention of Alzheimer's Disease by Vitamin E and Selenium Trial (PREADViSE). JAMA Neurol 2017;74(5):567-573 · 2017
Menopause hormone therapy (oestrogen-only or combined) in peri-/post-menopausal women
Basis not stated
No significant effect
Can be changed
- No significant association between MHT use and incident MCI or dementia in random-effects meta-analysis of 10 studies (1 RCT, 9 observational; 1,016,055 participants); subgroups by timing, duration and type also non-significant (pooled point estimate not given in abstract)
- Evidence: Moderate
- Other
A 2025 systematic review and meta-analysis found no evidence that menopause hormone therapy either raises or lowers dementia risk, and no effect of timing, duration or formulation. The authors conclude MHT should be prescribed for its other benefits and risks, not for dementia prevention. Certainty of evidence ranged from moderate to very low, and no study addressed premature ovarian insufficiency or testosterone.
PMID 41448220; PROSPERO CRD42025639384; primary studies searched 1 Jan 2000-20 Oct 2025; risk of bias via RoB 2 / ROBINS-E; GRADE. Funded by the Public Health Agency of Canada. The abstract reports the null result qualitatively; the numeric pooled RR was not in the source text we have, so the effect-size entry states the finding without inventing a point estimate.
Source: Melville M, He L, Desai R, et al. Menopause hormone therapy and risk of mild cognitive impairment or dementia: a systematic review and meta-analysis. Lancet Healthy Longev 2025;6(12):100803 · 2025
Statin use (observational cohorts and case-control studies)
Basis not stated
Decreases risk
Can be changed
- Pooled OR 0.80 (95% CI 0.75-0.86) for dementia (36 studies) and OR 0.68 (0.56-0.81) for Alzheimer's disease (21 studies) in statin users vs non-users; men OR 0.86 (0.81-0.92) and women OR 0.86 (0.81-0.92); high-potency statins 20% vs low-potency 16% dementia risk reduction (P=0.05 for heterogeneity)
- Evidence: Low
- Cardiovascular
Pooled observational evidence associates statin use with about 20% lower odds of dementia and 32% lower odds of Alzheimer's disease, with no difference between lipophilic and hydrophilic statins. Because this is observational (healthy-user and indication bias are likely) and no adequately designed randomised trial exists, the authors frame it as absence of neurocognitive harm plus a possible favourable effect, not proof of prevention.
PMID 34871380. Search to January 2021; restricted maximum-likelihood random-effects model. Evidence strength set to 'low' because all included studies are observational and the authors call for ad hoc RCTs. Contrast with the 'high-ldl-cholesterol' record (LDL as a risk factor) - statin benefit does not follow automatically from that association.
Source: Olmastroni E, Molari G, De Beni N, et al. Statin use and risk of dementia or Alzheimer's disease: a systematic review and meta-analysis of observational studies. Eur J Prev Cardiol 2022;29(5):804-814 · 2022
Poor periodontal health (periodontitis, tooth loss, deep pockets, alveolar bone loss)
Basis not stated
Increases risk
Can be changed
- Dementia HR 1.21 (95% CI 1.07-1.38; 23 longitudinal studies); cognitive decline OR 1.23 (1.05-1.44; 24 studies); tooth loss alone: dementia HR 1.13 (1.04-1.23), cognitive decline OR 1.23 (1.09-1.39); complete tooth loss dementia HR 1.23 (1.05-1.45)
- Evidence: Low
- Other
Longitudinal studies link poor periodontal health and tooth loss to roughly 20% higher dementia risk, but the review authors rate the evidence low quality, highly heterogeneous, and 'at least partly due to reverse causality' (early cognitive decline worsens oral care). Not among the Lancet Commission's 14 factors.
PMID 36073186; PMC9826143. Five databases searched to April 2022; 47 studies included (24 cognitive decline, 23 dementia); random-effects pooling. Partial tooth loss OR 1.50 (1.02-2.23) for cognitive decline. Recorded with the authors' caution about reverse causality.
Source: Asher S, Stephen R, Mantyla P, Suominen AL, Solomon A. Periodontal health, cognitive decline, and dementia: A systematic review and meta-analysis of longitudinal studies. J Am Geriatr Soc 2022;70(9):2695-2709 · 2022
Light-to-moderate alcohol intake vs abstention (dose-response, longitudinal studies)
Basis not stated
Decreases risk
Can be changed
- Dementia: RR 0.92 (95% CI 0.88-0.96) at 1-17.5 g/day and RR 1.23 (1.09-1.35) at >17.5 g/day vs 0 g/day (J-shaped; lowest risk ~15 g/day); cognitive dysfunction: RR 0.97 (0.95-0.99) at 1-30.5 g/day and RR 1.07 (1.01-1.15) at >30.5 g/day (lowest risk ~30 g/day)
- Evidence: Low
- Lifestyle
A 2024 dose-response meta-analysis of 17 longitudinal studies finds a J-shaped curve: light drinking (about one standard drink a day or less) is associated with slightly lower dementia risk than abstention, while heavier intake raises risk by about a quarter. The apparent protective effect of light drinking is contested because abstainer groups often include former heavy drinkers and people who stopped for health reasons (sick-quitter bias); this record should be read with the 'excessive-alcohol' record.
PMID 39038743. Search to April 2023; restricted cubic spline dose-response; 80,680 persons with 4,929 dementia cases and 13,530 persons with 1,579 cognitive-dysfunction cases. J-shape persisted in subgroups by age (<=65, >65) and study duration for dementia. Evidence strength 'low' reflects observational design and abstainer-bias concerns raised in the summary (the abstract itself does not discuss sick-quitter bias).
Source: Zarezadeh M, Mahmoudinezhad M, Faghfouri AH, et al. Alcohol consumption in relation to cognitive dysfunction and dementia: A systematic review and dose-response meta-analysis of comparative longitudinal studies. Ageing Res Rev 2024;100:102419 · 2024
Influenza vaccination (observational cohorts)
Basis not stated
No significant effect
Can be changed
- Overall population: HR 0.93 (95% CI 0.86-1.01), not significant; high-risk populations (CKD, COPD, vascular disease): 2-3 doses HR 0.84 (0.76-0.92), >=4 doses HR 0.43 (0.38-0.48)
- Evidence: Low
- Other
Across eight cohort studies with nearly 10 million people, influenza vaccination was not significantly associated with lower dementia incidence in the general population, although a dose-response association appeared in people with chronic kidney disease, COPD or vascular disease. Repeated vaccination is strongly confounded by health-seeking behaviour, so the subgroup finding should not be read as causal; contrast with the quasi-experimental zoster-vaccine record.
PMID 40601364. Search to 6 April 2025; 8 cohort studies, 9,938,696 subjects; Newcastle-Ottawa risk of bias low in all but one study; random-effects model. Direction recorded as no-significant-effect for the overall population (the primary comparison); the authors' own conclusion emphasises the dose-response finding.
Source: Yang WK, Shao SC, Liu CC, Chi CC. Influenza vaccination and risk of dementia: a systematic review and meta-analysis. Age Ageing 2025;54(7):afaf169 · 2025
High-school completion or above, and occupational complexity (COSMIC 9-cohort coordinated analysis)
Basis not stated
Decreases risk
Can be changed
- Pooled survival time ratio 1.26 (95% CI 1.09-1.47) for dementia-free survival with high-school completion or above vs less than high school (total effect); natural direct effect 1.18 (1.01-1.36); indirect effect via occupational complexity 1.06 (1.02-1.09); 28% of the education effect mediated by occupational complexity
- Evidence: Moderate
- Other
Across 10,195 older adults in nine cohorts from six countries, completing high school lengthened dementia-free survival by about a quarter, and adult occupational complexity independently added protection, explaining roughly a quarter of the education effect. A threshold pattern was seen: finishing high school mattered, with little extra gain from further education. Adds the adult-life occupation pathway to the 'less-education' record.
PMID 34776437; PMC8748312 (full text loaded). Median baseline age 74.1 (range 58-103); accelerated failure time models per cohort then meta-analysed; cumulative dementia incidence across cohorts 3%-22%. Pooled values quoted are from the mediation-analysis table (Table 5) of the full text; occupational complexity estimates in Table 4 varied by cohort (e.g., EAS Black and LEILA75+ protective) and the pooled Table 3/4 rows were in figures not captured as text.
Source: Hyun J, Hall CB, Katz MJ, et al. Education, Occupational Complexity, and Incident Dementia: A COSMIC Collaborative Cohort Study. J Alzheimers Dis 2022;85(1):179-196 · 2022
"Positive" means the trial met its own main goal. Check what that goal was: in most of these
it is a change in a cognitive test score, not a reduction in the number of people who developed dementia.
LatAm-FINGERS
Basis not stated
positive
What was tried: 2-year culturally adapted systematic multidomain lifestyle intervention (SLI: structured, supervised, monitored) vs flexible lifestyle intervention (FLI: health advice)
- 1,065 people
- Ages 60-77 (mean 67.5)
- For 2 years
- p = <0.0001
What was measured: co-primary: feasibility (RE-AIM Reach/Implementation/Maintenance) and change in global cognitive composite over 2 years
What was found: Mean annual change 0.31 SD (95% CI 0.28-0.34) SLI vs 0.20 SD (0.17-0.23) FLI; between-group difference 0.11 SD per year (95% CI 0.06-0.15)
Who was studied: At-risk adults 60-77 (CAIDE score >=6 and suboptimal cognitive performance) in 11 Latin American countries; 75% women; 59% Mestizo, 27% White
Limitations: Comparator was an active health-advice arm, not usual care; both groups improved (practice effects likely); participants and staff unmasked; analytic sample 1065 of 1719 assessed; higher dropout in FLI (20.2% vs 15.2%); adverse events far more frequent in SLI (412 vs 66, mostly musculoskeletal). NCT06492967.
Replication: replicated
Source: Lancet 2026;408(10553):417-429 · 2026 · PubMed 42442374 · doi:10.1016/S0140-6736(26)01278-X
Physical Exercise for Prevention of Dementia Study (48-month multimodal training RCT, Italy)
Basis not stated
positive
What was tried: 48 months of supervised moderate-to-high-intensity multimodal training (aerobic, resistance, stretching) vs usual habits
- 882 people
- Ages older adults (ages not given in abstract)
- For 48 months
- p = 0.008 (healthy); 0.052 (SMC)
What was measured: 48-month change in MMSE
What was found: Healthy participants: exercise group higher MMSE than control (between-group effect p=0.008, partial eta-squared 0.007; time x group interaction partial eta-squared 0.025); SMC group between-group p=0.052 (partial eta-squared 0.004; interaction partial eta-squared 0.031); better memory, attention and reasoning in healthy and SMC exercisers
Who was studied: 882 community-dwelling older adults classed as healthy, subjective memory complaints (SMC) or MCI; 674 in final analysis
Limitations: Single-blind; 24% not in final analysis (674/882); MCI subgroup too small for conclusive analysis (authors); very small effect sizes; MMSE has ceiling effects in healthy adults.
Replication: not-replicated
Source: Iuliano E et al. Front Aging 2026;7:1847451 · 2026 · PubMed 42639433 · doi:10.3389/fragi.2026.1847451
Digital multidomain cognitive intervention in older adults at high dementia risk (Fujian, China)
Basis not stated
positive
What was tried: 6-month WeChat-delivered digital multidomain cognitive intervention vs control
- 166 people
- Ages >=60
- For 6 months
- p = 0.037 (MoCA)
What was measured: general cognitive function (MoCA)
What was found: MoCA improved vs control (t=2.106); ROCFT immediate and long-delay recall improved; UCLA loneliness reduced (Z=-2.641); no other significant differences
Who was studied: 166 adults >=60 with modified dementia risk score >79 at Fujian Provincial Hospital and 4 community health centres (April-December 2024); 154 (92.8%) completed
Limitations: Abstract does not enumerate limitations; small single-region sample (166), 6-month duration, no long-term follow-up, multiple secondary outcomes with borderline p-values.
Replication: not-replicated
Source: Yan Y et al. J Clin Psychiatry 2026;87(1):25m15860 · 2026 · PubMed 41499182 · doi:10.4088/JCP.25m15860
J-MINT (secondary: vascular risk factor moderation)
Basis not stated
positive
What was tried: Same as J-MINT 18-month multidomain intervention; secondary analysis by presence of untreated/uncontrolled vascular risk factors (BP, HbA1c, HDL, non-HDL cholesterol)
- 531 people
- Ages 65-85
- For 18 months
- p = 0.032 (interaction)
What was measured: interaction of intervention x VRF status on change in average neuropsychological Z score over 18 months
What was found: In participants with VRFs: Z score difference 0.11 (95% CI 0.02-0.20); no benefit in those without VRFs; interaction p=0.032
Who was studied: J-MINT participants (MCI, 65-85); 298 had >=1 untreated or uncontrolled VRF
Limitations: Secondary/subgroup analysis of a trial that was null on its primary outcome; hypothesis-generating. UMIN000038671.
Replication: not-replicated
Source: Alzheimers Dement 2025 (J-MINT investigators) · 2025 · PubMed 41222037 · doi:10.1002/alz.70822
CRHCP (China Rural Hypertension Control Project) dementia outcome
Basis not stated
positive
What was tried: Non-physician community healthcare provider-led stepped-care antihypertensive titration to systolic <130 / diastolic <80 mm Hg (with physician supervision, home BP monitoring, health coaching) vs usual care; village-level cluster randomisation
- 33,995 people
- Ages 40+
- For 48 months
- p = 0.0035
What was measured: all-cause dementia (blinded endpoint adjudication)
What was found: All-cause dementia RR 0.85 (95% CI 0.76-0.95); net SBP reduction 22.0 mm Hg (95% CI 20.6-23.4), DBP reduction 9.3 mm Hg (95% CI 8.7-10.0); serious adverse events RR 0.94 (95% CI 0.91-0.98)
Who was studied: Adults >=40 with uncontrolled hypertension in 326 rural Chinese villages (163 intervention, 163 usual care)
Limitations: Open-label cluster design; rural China with very large achievable BP reduction (22 mm Hg) and low baseline treatment, so generalisability to well-treated populations is uncertain; only a 4-year window. NCT03527719.
Replication: not-replicated
Source: He J et al. Nat Med 2025;31(6):2054-2061 · 2025 · PubMed 40258956 · doi:10.1038/s41591-025-03616-8
Maintain Your Brain (MYB)
Basis not stated
positive
What was tried: 3-year online, personalised multidomain coaching in 2-4 modules targeting physical activity, nutrition, cognitive activity (computerised brain training) and depression/anxiety, vs control receiving module-eligible information only
- 6,104 people
- Ages 55-77
- For 3 years
- p = <0.001
What was measured: 3-year change in global cognitive composite
What was found: Change in z score 0.28 (95% CI 0.25-0.32) intervention vs 0.10 (95% CI 0.07-0.13) control; between-group difference 0.18 (95% CI 0.13-0.23)
Who was studied: Dementia-free community-dwelling Australians aged 55-77 with modifiable dementia risk factors (45 and Up Study cohort); 64% female
Limitations: Online-only cognitive testing (potential overlap between brain-training module practice and outcome tests); single-blind; control received information only; younger and healthier than FINGER-type samples; 'social' tag reflects the depression/anxiety module (closest schema category). ACTRN12618000851268.
Replication: not-replicated
Source: Brodaty H et al. Nat Med 2025;31(2):565-573 · 2025 · PubMed 39875685 · doi:10.1038/s41591-024-03351-6
ACHIEVE (secondary: benefit by predicted risk of cognitive decline)
Basis not stated
positive
What was tried: Hearing intervention (audiological counselling + hearing aids) vs health education control
- 977 people
- Ages 70-84
- For 3 years
What was measured: interaction between predicted risk of cognitive decline and randomisation on 3-year cognitive decline
What was found: Among participants in the top quartile of predicted risk, 3-year cognitive decline was 61.6% (95% CI 33.7%-94.1%) slower with hearing intervention than control
Who was studied: 977 ACHIEVE participants; predicted-risk model developed in 2692 dementia-free ARIC participants
Limitations: Secondary/subgroup analysis; primary ACHIEVE result was null; effect-modification analyses are hypothesis-generating. NCT03243422.
Replication: not-replicated
Source: Pike JR et al. Alzheimers Dement 2025;21(5):e70156 · 2025 · PubMed 40369891 · doi:10.1002/alz.70156
ACHIEVE (secondary: social isolation and loneliness)
Basis not stated
positive
What was tried: Best-practice hearing intervention (4 audiologist sessions, hearing aids, counselling, education) vs health-education control, 3 years
- 977 people
- Ages 70-84
- For 3 years
What was measured: exploratory: social isolation (Cohen Social Network Index) and loneliness (UCLA Loneliness Scale) over 3 years
What was found: Hearing intervention vs control: social network size +1.05 (95% CI 0.01-2.09), diversity +0.19 (95% CI 0.02-0.36), embeddedness +0.27 (95% CI 0.09-0.44); loneliness -0.94 (95% CI -1.78 to -0.11)
Who was studied: 977 adults 70-84 with untreated hearing loss without substantial cognitive impairment at 4 US sites (238 from ARIC, 739 de novo); mean age 76.3; mean better-ear PTA 39.4 dB
Limitations: Authors: exploratory outcomes; clinical meaningfulness of retaining ~1 additional social contact is unknown and loneliness changes were not clinically meaningful.
Replication: not-replicated
Source: Reed NS et al. JAMA Intern Med 2025;185(7):797-806 · 2025 · PubMed 40354063 · doi:10.1001/jamainternmed.2025.1140
SMARRT
Basis not stated
positive
What was tried: 2-year personalised multidomain risk-reduction: participant-chosen goals across 8 targeted risk factors with health coaching and nurse visits vs health education control; shifted to remote delivery during COVID-19
- 172 people
- Ages 70-89
- For 2 years
- p = 0.02
What was measured: change in composite modified Neuropsychological Test Battery
What was found: Composite cognition ATE 0.14 SD (95% CI 0.03-0.25), described as 74% improvement vs control change; composite risk-factor score ATE 0.11 SD (95% CI 0.01-0.20, P=0.03); QOL ATE 0.81 points (95% CI -0.21 to 1.84, P=0.12)
Who was studied: Adults 70-89 at elevated dementia risk (>=2 of 8 targeted risk factors) from Kaiser Permanente Washington primary care; 62.8% women; mean age 75.7
Limitations: Small pilot-scale trial (n=172); COVID-19 forced switch to remote delivery; musculoskeletal pain 14 vs 0. NCT03683394.
Replication: not-replicated
Source: Yaffe K et al. JAMA Intern Med 2024;184(1):54-62 (online Nov 2023) · 2024 · PubMed 38010725 · doi:10.1001/jamainternmed.2023.6279
Semaglutide target-trial emulation (TriNetX EHR, Wang et al.)
Modelled estimate
positive
What was tried: Semaglutide vs seven other antidiabetic drug classes in type 2 diabetes (OBSERVATIONAL target-trial emulation, not an RCT)
- 1,094,761 people
- For 3-year follow-up
What was measured: first-ever diagnosis of Alzheimer's disease
What was found: HR 0.33 (95% CI 0.21-0.51) vs insulin (strongest); HR 0.59 (95% CI 0.37-0.95) vs other GLP-1RAs (weakest); described as 40-70% lower risk across comparators
Who was studied: 1,094,761 eligible US patients with type 2 diabetes and no prior AD diagnosis, from EHR database of 116 million patients
Limitations: OBSERVATIONAL/EHR-derived, not randomised; diagnosis-code outcome; confounding by indication and healthy-user bias possible; the RCT test of semaglutide (evoke/evoke+, symptomatic AD) was blank.
Replication: not-replicated
Source: Wang W et al. Alzheimers Dement 2024;20(12):8661-8672 · 2024 · PubMed 39445596 · doi:10.1002/alz.14313
Ornish intensive lifestyle trial (MCI/early AD)
Basis not stated
positive
What was tried: 20-week intensive multidomain lifestyle programme (whole-food plant-based diet, exercise, stress management, group support) vs wait-list usual care
- 51 people
- Ages 45-90 (mean 73.5)
- For 20 weeks
- p = 0.001 (CGIC); 0.032 (CDR-SB); 0.037 (CDR-G); 0.053 (ADAS-Cog)
What was measured: change in CGIC, ADAS-Cog, CDR-SB, CDR-Global
What was found: Between-group differences significant for CGIC (p=0.001), CDR-SB (p=0.032), CDR-Global (p=0.037); borderline ADAS-Cog (p=0.053); abstract gives no numeric effect estimates. Plasma Abeta42/40 ratio rose in intervention and fell in control (p=0.003)
Who was studied: Adults 45-90 with MCI or early dementia due to AD (MoCA >=18), plasma Abeta42/40 <0.0672 in all; multicentre USA
Limitations: Very small (n=51), phase 2, 20 weeks, wait-list (unblinded) control, retrospectively registered (NCT04606420), symptomatic population (treatment not primary prevention), no numeric effect sizes in abstract; nonparametric tests on ordinal scales.
Replication: not-replicated
Source: Ornish D et al. Alzheimers Res Ther 2024;16(1):122 · 2024 · PubMed 38849944 · doi:10.1186/s13195-024-01482-z
PRODEMOS
Basis not stated
positive
What was tried: Coach-supported mobile health (smartphone app) lifestyle intervention targeting dementia risk factors vs control, 12-18 months
- 1,488 people
- Ages 55-75
- For mean 16 months (SD 2.5)
What was measured: change in CAIDE dementia risk score (NOT a cognitive outcome)
What was found: CAIDE score improved 0.16 points intervention vs 0.01 control; mean difference -0.16 (95% CI -0.29 to -0.03)
Who was studied: Adults 55-75 with >=2 dementia risk factors: low socioeconomic status in the UK, or general population in China
Limitations: Surrogate risk-score outcome; modest effect (0.16 CAIDE points); only 10% of invited responded; 50% sustained participation; open-label; authors state a larger long-follow-up RCT is needed to show cognitive/dementia effects. ISRCTN15986016.
Replication: not-replicated
Source: Moll van Charante EP et al. Lancet Healthy Longev 2024;5(6):e431-e442 · 2024 · PubMed 38763155 · doi:10.1016/S2666-7568(24)00068-0
AgeWell.de
Basis not stated
positive
What was tried: Pragmatic multicomponent lifestyle intervention delivered via general practice (optimisation of nutrition, medication, physical, social and cognitive activity) vs general health advice, 2 years
- 461 people
- Ages 60-77
- For 24 months
What was measured: secondary analysis: change in LIBRA (LIfestyle for BRAin health) dementia risk index
What was found: LIBRA score reduced by b = -0.63 (95% CI -1.14 to -0.12); driven by diet (OR 1.60, 95% CI 1.16-2.22) and hypertension (OR 1.61, 95% CI 1.19-2.18) improvements
Who was studied: German primary-care patients 60-77 with CAIDE score >=9 (cluster-randomised by GP practice); LIBRA analysis n=461 with complete 24-month data
Limitations: Secondary analysis on a risk index, not cognition; only 461 of the trial's ~819 participants had complete LIBRA data; several risk factors did not improve. DRKS00013555.
Replication: not-replicated
Source: Zülke AE et al. Alzheimers Dement 2024;20(8):5684-5694 · 2024 · PubMed 38967275 · doi:10.1002/alz.14097
I-CONECT (Internet-based Conversational Engagement)
Basis not stated
positive
What was tried: Semi-structured cognitively stimulating video-chat conversations with trained interviewers 4x/week for 6 months (induction) then 2x/week for 6 months (maintenance) vs control; both arms received weekly 10-minute telephone check-ins
- 186 people
- Ages 75+
- For 12 months (6 induction + 6 maintenance)
- p = 0.03 (MoCA primary); 0.03 (semantic fluency); 0.04 (Craft Story); 0.02 (fMRI)
What was measured: global cognition (MoCA) after the 6-month induction period
What was found: MoCA +1.75 points vs control after induction; semantic fluency +2.56 points in normal-cognition subgroup; Craft Story immediate recall +2.19 points in MCI subgroup at end of maintenance; increased dorsal attention network connectivity on rs-fMRI
Who was studied: Socially isolated adults 75+ with normal cognition or MCI, multisite US trial (186 randomized)
Limitations: Authors note COVID-19-related protocol modifications; small sample (186) with subgroup findings; fMRI sample size limited; emotional well-being improved in both arms.
Replication: not-replicated
Source: Dodge HH et al. Gerontologist 2024;64(4):gnad147 · 2024 · PubMed 37935416 · doi:10.1093/geront/gnad147
Suvorexant acute CSF study (Lucey et al.)
Basis not stated
positive
What was tried: Single dose suvorexant 10 mg or 20 mg (dual orexin receptor antagonist, insomnia drug) vs placebo with serial CSF sampling over 36 hours
- 38 people
- Ages 45-65
- For 36 hours (acute)
What was measured: CSF amyloid-beta, tau and phospho-tau concentrations (mass spectrometry)
What was found: P-tau181 phosphorylation ratio decreased ~10-15% with suvorexant 20 mg vs placebo; amyloid-beta decreased ~10-20% vs placebo from 5 h after dosing; no decrease at tau-S202 or tau-T217
Who was studied: Cognitively unimpaired adults 45-65
Limitations: Tiny acute mechanistic study; no cognitive or clinical outcome; chronic-treatment trials needed per authors.
Replication: not-replicated
Source: Lucey BP et al. Ann Neurol 2023;94(1):27-40 · 2023 · PubMed 36897120 · doi:10.1002/ana.26641
Meta-analysis: hearing aids/cochlear implants and cognitive decline (Yeo et al.)
Basis not stated
positive
What was tried: Hearing aid or cochlear implant use vs uncorrected hearing loss (pooled observational studies and trials)
- 137,484 people
- For 2-25 years (long-term studies)
What was measured: any cognitive decline / dementia (long-term); short-term cognitive test score change
What was found: Long-term cognitive decline HR 0.81 (95% CI 0.76-0.87), I2=0% (8 studies, n=126,903); short-term cognitive test scores ratio of means 1.03 (95% CI 1.02-1.04), I2=0% (11 studies, n=568)
Who was studied: Adults with hearing loss; 31 studies (25 observational, 6 trials), 137,484 participants; 19 in quantitative synthesis
Limitations: OBSERVATIONAL-dominated pooled estimate (confounding by indication, healthy-user bias); published before ACHIEVE, whose primary result was null; not a trial effect size.
Replication: not-replicated
Source: Yeo BSY et al. JAMA Neurol 2023;80(2):134-141 · 2023 · PubMed 36469314 · doi:10.1001/jamaneurol.2022.4427
SUPERBRAIN (South Korea; facility- and home-based multidomain intervention)
Basis not stated
positive
What was tried: 24-week multidomain intervention (vascular risk management, cognitive training, social activity, physical exercise, nutrition guidance, motivational enhancement) delivered facility-based (3x/week) or home-based vs general health advice control
- 152 people
- Ages 60-79
- For 24 weeks
- p = 0.004 (each intervention arm vs control)
What was measured: feasibility (retention, adherence, and no worse RBANS than control)
What was found: Retention 88.2% (facility) and 96.1% (home); adherence 94.5% and 96.8%; RBANS total index change +5.46 (SD 7.50) facility and +5.50 (SD 8.14) home vs -0.74 (SD 11.51) control
Who was studied: Korean adults 60-79 without dementia with >=1 modifiable dementia risk factor; facility-based n=51, home-based n=51, control n=50
Limitations: Feasibility trial: small (152), 24 weeks, primary outcome was feasibility rather than cognition; outcome-assessor blinded only.
Replication: not-replicated
Source: Moon SY et al. Aging (Albany NY) 2021;13(12):15898-15916 · 2021 · PubMed 34148030 · doi:10.18632/aging.203213
Meta-analysis: BP lowering and incident dementia/cognitive impairment (Hughes et al.)
Basis not stated
positive
What was tried: Antihypertensive blood-pressure lowering vs placebo, alternative agents or higher targets; 14 RCTs (12 in primary meta-analysis)
- 96,158 people
- Ages mean 69
- For mean 4.1 years (primary outcome trials)
What was measured: dementia or cognitive impairment
What was found: Dementia or cognitive impairment OR 0.93 (95% CI 0.88-0.98), 7.0% vs 7.5%, ARR 0.39% (95% CI 0.09-0.68%), I2=0% (12 trials, n=92,135); cognitive decline OR 0.93 (95% CI 0.88-0.99), ARR 0.71% (95% CI 0.19-1.2%), I2=36.1% (8 trials); no significant change in cognitive test scores
Who was studied: 96,158 RCT participants; mean age 69; 42.2% women; mean baseline BP 154/83.3 mm Hg; mean follow-up 49.2 months
Limitations: POOLED from trials not designed for dementia; small absolute effect (0.39%); heterogeneous comparators; predates CRHCP (2025) and SPRINT extended follow-up.
Replication: replicated
Source: Hughes D et al. JAMA 2020;323(19):1934-1944 · 2020 · PubMed 32427305 · doi:10.1001/jama.2020.4249
HATICE
Basis not stated
positive
What was tried: Coach-supported interactive internet platform for self-management of cardiovascular risk factors (BP, LDL, BMI, diet, exercise, smoking) vs static control platform, 18 months
- 2,724 people
- Ages 65+
- For 18 months
- p = 0.008
What was measured: change in standardised composite Z score of systolic BP, LDL cholesterol and BMI (cardiovascular risk profile; NOT a cognitive outcome)
What was found: Composite improved 0.09 intervention vs 0.04 control; mean difference -0.05 (95% CI -0.08 to -0.01). Components: SBP -1.79 vs -0.67 mmHg (diff -1.12, 95% CI -2.51 to 0.27); BMI -0.23 vs -0.08 kg/m2 (diff -0.15, -0.28 to -0.01); LDL -0.12 vs -0.07 mmol/L (diff -0.05, -0.11 to 0.01). Cardiovascular disease HR 0.86 (95% CI 0.52-1.43)
Who was studied: Community-dwelling adults >=65 years at increased cardiovascular risk in the Netherlands, Finland and France
Limitations: Primary outcome is a cardiovascular risk composite, not cognition; effect modest; open-label (blinded endpoint); individual risk-factor differences mostly not significant. ISRCTN48151589.
Replication: not-replicated
Source: Richard E et al. Lancet Digit Health 2019;1(8):e424-e434 · 2019 · PubMed 33323224 · doi:10.1016/S2589-7500(19)30153-0
FINGER (prespecified subgroup analysis)
Basis not stated
positive
What was tried: FINGER 2-year multidomain intervention vs regular health advice
- 1,260 people
- Ages 60-77
- For 2 years
- p = >0.05 for all interactions
What was measured: effect modification of NTB z-score change by sex, age, education, income, baseline MMSE, BMI, BP, cholesterol, glucose, CV risk and comorbidity
What was found: No characteristic modified intervention response (all interaction P > 0.05); benefit consistent across subgroups
Who was studied: FINGER participants (60-77, at risk)
Limitations: Subgroup analyses are underpowered to detect modification; absence of interaction is not proof of homogeneity.
Replication: replicated
Source: Rosenberg A et al. Alzheimers Dement 2018;14(3):263-270 · 2018 · PubMed 29055814 · doi:10.1016/j.jalz.2017.09.006
FINGER (prespecified APOE e4 subgroup analysis)
Basis not stated
positive
What was tried: Multidomain lifestyle (diet, exercise, cognitive training, vascular risk management) vs general health advice
- 1,109 people
- Ages 60-77 (mean 69.3)
- For 2 years
What was measured: change in NTB total score by APOE e4 status
What was found: Intervention-control difference in annual NTB change 0.037 (95% CI 0.001-0.073) in e4 carriers vs 0.014 (95% CI -0.011 to 0.039) in noncarriers; carrier-noncarrier difference in effect 0.023 (95% CI -0.021 to 0.067), not significant
Who was studied: FINGER participants with APOE genotype (1109 analysed: 362 e4 carriers, 747 noncarriers)
Limitations: Subgroup analysis; interaction not significant; benefit in noncarriers alone not significant. NCT01041989.
Replication: replicated
Source: Solomon A et al. JAMA Neurol 2018;75(4):462-470 · 2018 · PubMed 29356827 · doi:10.1001/jamaneurol.2017.4365
FINGER
Measured
positive
What was tried: Multidomain lifestyle: diet + exercise + cognitive training + vascular risk monitoring, 2 years, vs general health advice control
- 1,260 people
- Ages 60-77
- For 2 years
- p = 0.030
What was measured: change in cognition (comprehensive neuropsychological test battery, NTB total Z score)
What was found: Between-group difference in change of NTB total Z score per year 0.022 (95% CI 0.002-0.042); mean 2-year change 0.20 intervention vs 0.16 control
Who was studied: Finnish community-dwelling at-risk older adults (CAIDE Dementia Risk Score >=6, cognition at mean or slightly lower than expected for age), recruited from national surveys
Limitations: Small absolute effect (0.022 Z/year); 2-year duration; control group also improved; adverse events (musculoskeletal pain) 7% vs 1%; single-country proof-of-concept. NCT01041989.
Replication: replicated
Source: Ngandu T et al. Lancet 2015;385(9984):2255-63 · 2015 · PubMed 25771249 · doi:10.1016/S0140-6736(15)60461-5
PREDIMED (Barcelona cognitive substudy)
Basis not stated
positive
What was tried: Mediterranean diet supplemented with extra-virgin olive oil (1 L/week) or with mixed nuts (30 g/day) vs control diet (advice to reduce dietary fat)
- 447 people
- Ages 55-80 (PREDIMED design); mean 66.9
- For median 4.1 years
- p = 0.005 (global, olive oil vs control); 0.003 (frontal); 0.04 (memory, nuts)
What was measured: rate of cognitive change (memory, frontal, global composites from neuropsychological battery)
What was found: Global composite change: +0.05 (95% CI -0.11 to 0.21) MedDiet+olive oil (P=0.005 vs control), -0.05 (-0.27 to 0.18) MedDiet+nuts, -0.38 (-0.57 to -0.18) control; frontal composite +0.23 (0.03-0.43) olive oil (P=0.003 vs control), +0.03 nuts, -0.33 control; memory composite +0.04 olive oil, +0.09 nuts (P=0.04 vs control), -0.17 control
Who was studied: Cognitively healthy volunteers at high cardiovascular risk, Barcelona, Spain; 52.1% women; mean age 66.9
Limitations: Single-site substudy; 25% lost to follow-up testing; control group declined unusually steeply; PREDIMED main trial was later re-analysed/republished (2018) over randomisation irregularities at some sites; age range from parent trial design, not this abstract.
Replication: not-replicated
Source: Valls-Pedret C et al. JAMA Intern Med 2015;175(7):1094-1103 · 2015 · PubMed 25961184 · doi:10.1001/jamainternmed.2015.1668
VITACOG
Basis not stated
positive
What was tried: High-dose B vitamins (folic acid 0.8 mg/d, vitamin B12 0.5 mg/d, vitamin B6 20 mg/d) vs placebo, 24 months
- 271 people
- Ages 70+
- For 24 months
- p = 0.001
What was measured: change in rate of whole-brain atrophy on serial volumetric MRI
What was found: Mean atrophy rate per year 0.76% (95% CI 0.63-0.90) active vs 1.08% (0.94-1.22) placebo; in participants with baseline homocysteine >13 umol/L atrophy rate 53% lower with treatment
Who was studied: Adults >70 years with mild cognitive impairment, single centre (Oxford, UK)
Limitations: Small single-centre trial; MRI endpoint in a self-selected subset (187 of 271 volunteered; 168 completed); surrogate (atrophy) not clinical outcome; no large confirmatory trial has replicated a dementia-incidence benefit. ISRCTN94410159.
Replication: not-replicated
Source: Smith AD et al. PLoS One 2010;5(9):e12244 · 2010 · PubMed 20838622 · doi:10.1371/journal.pone.0012244
Syst-Eur (vascular dementia project)
Basis not stated
positive
What was tried: Nitrendipine 10-40 mg/d with optional enalapril and/or hydrochlorothiazide vs placebo (target SBP <150)
- 2,418 people
- Ages 60+
- For median 2.0 years
- p = 0.05
What was measured: incidence of dementia (DSM-III-R, MMSE-screened)
What was found: Dementia incidence reduced 50%: 7.7 to 3.8 cases per 1000 patient-years (21 vs 11 cases); authors estimate 19 dementia cases prevented per 1000 patients treated 5 years
Who was studied: Adults >=60 with isolated systolic hypertension (SBP 160-219, DBP <95), no dementia; Europe
Limitations: Only 32 dementia events; borderline p=0.05; short follow-up; MMSE-triggered ascertainment; effect size larger than any subsequent BP trial.
Replication: not-replicated
Source: Forette F et al. Lancet 1998;352(9137):1347-51 · 1998 · PubMed 9802273 · doi:10.1016/s0140-6736(98)03086-4
ACTIVE (20-year Medicare-claims follow-up)
Basis not stated
mixed
What was tried: Four-arm cognitive training RCT: memory training, reasoning training, speed-of-processing training (with optional booster sessions), or no-contact control; linked to Medicare claims 1999-2019
- 2,021 people
- Ages 65+
- For 20 years follow-up
What was measured: claims-based diagnosed Alzheimer's disease and related dementias (Chronic Conditions Warehouse algorithm)
What was found: Speed training with >=1 booster session HR 0.75 (95% CI 0.59-0.95); speed training without booster HR 1.01 (95% CI 0.81-1.27); no main effect of memory or reasoning training
Who was studied: ACTIVE participants enrolled in traditional Medicare at baseline (older adults 65+, diverse US sample)
Limitations: Claims-based (not adjudicated) dementia; booster completion is post-randomisation (self-selected), so the HR 0.75 is not a pure ITT effect; original ACTIVE trial had no primary dementia outcome; sample restricted to traditional Medicare enrolees.
Replication: not-replicated
Source: Alzheimers Dement (N Y) 2026;12(1):e70197 · 2026 · PubMed 41669119 · doi:10.1002/trc2.70197
ACHIEVE (secondary: plasma GFAP and NfL)
Basis not stated
mixed
What was tried: Hearing intervention vs health education control
- 164 people
- Ages 70-84 (mean 78.1)
- For 3 years
- p = 0.019 (GFAP); 0.098 (NfL)
What was measured: 3-year change in plasma GFAP (neuroinflammation) and NfL (neurodegeneration)
What was found: GFAP change: intervention -0.026 (95% CI -0.144 to 0.093) vs control 0.149 (0.039 to 0.260); difference -0.175 (95% CI -0.322 to -0.028). NfL: 0.171 vs 0.330; difference -0.159 (95% CI -0.348 to 0.029)
Who was studied: ACHIEVE participants recruited from the ARIC cohort with plasma at baseline and 3 years (n=164; mean age 78.1)
Limitations: Small ARIC-only subsample (n=164); non-specific biomarkers; secondary analysis. NCT03243422.
Replication: not-replicated
Source: Pike JR et al. EClinicalMedicine 2026;99:104164 · 2026 · PubMed 42733779 · doi:10.1016/j.eclinm.2026.104164
US POINTER
Basis not stated
mixed
What was tried: Structured high-intensity multidomain lifestyle (physical + cognitive activity, MIND-style healthy diet, social engagement, cardiovascular health monitoring; team-based with coaching and accountability) vs self-guided lower-intensity version of the same domains. NOTE: no no-intervention/usual-care control arm.
- 2,111 people
- Ages 60-79
- For 2 years
- p = 0.008
What was measured: difference between arms in annual rate of change in global cognitive function
What was found: Annual rate of increase 0.243 SD (95% CI 0.227-0.258) structured vs 0.213 SD (95% CI 0.198-0.229) self-guided; between-group difference 0.029 SD/year (95% CI 0.008-0.050)
Who was studied: US older adults at risk of cognitive decline: sedentary lifestyle + suboptimal diet + >=2 of family history of memory impairment, cardiometabolic risk, race/ethnicity, older age, sex; 5 US sites
Limitations: Both arms improved substantially (0.24 and 0.21 SD/yr, likely practice effects + self-guided arm itself being an intervention); no true control arm so absolute effect of lifestyle change vs nothing cannot be estimated; small between-group difference (0.029 SD/yr); clinical relevance and durability unresolved per authors; single-blind. NCT03688126.
Replication: replicated
Source: Baker LD et al. JAMA 2025;334(8):681-691 · 2025 · PubMed 40720610 · doi:10.1001/jama.2025.12923
CPAP in OSA (multicentre China RCT, NCT02886156)
Basis not stated
mixed
What was tried: 12 months of continuous positive airway pressure (CPAP) plus best supportive care vs best supportive care alone
- 148 people
- Ages middle-aged (not specified in abstract)
- For 12 months (primary endpoint at 6 months)
- p = 0.91 (primary)
What was measured: Montreal Cognitive Assessment (MoCA) score at 6 months
What was found: MoCA difference -0.04 (95% CI -0.72 to 0.65), P=0.91 [null]; DMN functional connectivity difference -13.73 (95% CI -23.40 to -4.06), P=0.01; cortical thickness difference -0.06 mm (95% CI -0.10 to -0.01), P=0.02
Who was studied: Middle-aged adults with obstructive sleep apnea (AHI >=15/h) and normal cognition; 5 hospitals, China, 2017-2021
Limitations: Small; cognitively normal participants with ceiling on MoCA; short; not an older/at-risk-for-dementia population; 'sensory' tag used as closest schema category for a sleep/breathing intervention.
Replication: not-replicated
Source: Am J Respir Crit Care Med 2025;211(4):628-636 · 2025 · PubMed 39998447 · doi:10.1164/rccm.202406-1170OC
SPRINT MIND (extended follow-up)
Basis not stated
mixed
What was tried: Intensive (SBP <120) vs standard (SBP <140) treatment for 3.3 years; cognitive status re-ascertained by telephone from Dec 2019
- 9,361 people
- Ages 50+
- For median 7 years follow-up
What was measured: probable dementia (prespecified secondary analysis with extended follow-up)
What was found: Probable dementia HR 0.86 (95% CI 0.72-1.02), 8.5 vs 10.2 per 1000 person-years (248 vs 293 cases); MCI HR 0.87 (95% CI 0.76-1.00); MCI or probable dementia HR 0.89 (95% CI 0.79-0.99)
Who was studied: SPRINT participants; 7221 (77%) eligible for recontact, cognitive status ascertained for 4232 (59%); mean age 67, 36% female
Limitations: Still under-accrued for dementia (216 of 326 target cases); only 59% of eligible re-contacted; telephone ascertainment; Class II evidence.
Replication: not-replicated
Source: Neurology 2025;104(3):e213334 (SPRINT Research Group) · 2025 · PubMed 39819096 · doi:10.1212/WNL.0000000000213334
DIAN-TU gantenerumab open-label extension
Basis not stated
mixed
What was tried: High-dose subcutaneous gantenerumab up to 1500 mg every 2 weeks, open-label, for up to 3 years after the double-blind DIAN-TU-001 period
- 73 people
- Ages adults at risk for dominantly inherited AD (ages not given in abstract)
- For 3 years (stopped early after interim analysis; 13 completed 3 years)
- p = <0.0001 (PiB-PET SUVR); HRs not significant
What was measured: final analysis: 11C-PiB-PET SUVR change at 3 years (mITT n=55); prespecified interim: CDR-SB clinical decline in asymptomatic carriers vs external controls
What was found: Interim HR for CDR-SB decline in asymptomatic carriers 0.79 (95% CI 0.47-1.32; n=53) for any gantenerumab exposure and 0.53 (95% CI 0.27-1.03; n=22) for the longest-treated group; PiB-PET SUVR change from OLE baseline to year 3: -0.71 (95% CI -0.88 to -0.53)
Who was studied: Dominantly inherited AD mutation carriers who had completed DIAN-TU-001 and knew their mutation status; 18 sites in 8 countries; 74 recruited, 73 treated
Limitations: Authors: conclusions limited by open-label design and use of external controls; study stopped early by sponsor (no regulatory path for gantenerumab) - 47 of 73 stopped dosing for that reason and only 13 completed 3 years; small numbers (HR estimates on n=53 and n=22).
Replication: not-replicated
Source: Bateman RJ et al. Lancet Neurol 2025;24(4):316-330 · 2025 · PubMed 40120616 · doi:10.1016/S1474-4422(25)00024-9
ACHIEVE
Basis not stated
mixed
What was tried: Hearing intervention: audiological counselling + provision and fitting of hearing aids vs health education control (individual sessions with health educator on chronic disease prevention); follow-up every 6 months
- 977 people
- Ages 70-84 (mean 76.8)
- For 3 years
- p = 0.96 (primary); 0.010 (cohort interaction); 0.027 (ARIC subgroup)
What was measured: 3-year change in global cognition standardised factor score from comprehensive neurocognitive battery
What was found: Total cohort: 3-year change -0.200 (95% CI -0.256 to -0.144) hearing vs -0.202 (-0.258 to -0.145) control; difference 0.002 (95% CI -0.077 to 0.081), p=0.96 [blank]. Prespecified sensitivity analysis by cohort (p interaction=0.010): ARIC cohort difference 0.191 (95% CI 0.022 to 0.360), p=0.027, described as a 48% reduction in 3-year cognitive change; de novo cohort difference -0.061 (95% CI -0.151 to 0.028), p=0.18
Who was studied: US adults 70-84 with untreated hearing loss, without substantial cognitive impairment; 4 community sites; two recruitment sources: ARIC cohort (n=238, older, more risk factors, lower baseline cognition) and healthy de novo volunteers (n=739); 88% White
Limitations: Primary analysis null; the widely cited 48% figure is a prespecified sensitivity/subgroup analysis in the higher-risk ARIC cohort (24% of sample) and needs replication; unmasked; 88% White; healthy-volunteer de novo cohort declined less than expected. NCT03243422.
Replication: not-replicated
Source: Lin FR et al. Lancet 2023;402(10404):786-797 · 2023 · PubMed 37478886 · doi:10.1016/S0140-6736(23)01406-X
COSMOS-Mind
Basis not stated
mixed
What was tried: 2x2 factorial: cocoa extract (500 mg/day flavanols) vs placebo and daily multivitamin-mineral (Centrum Silver) vs placebo, 3 years; telephone cognitive assessment
- 2,262 people
- Ages 65+ (women), 60+ (men) per COSMOS design; mean 73
- For 3 years
- p = 0.28 (cocoa); 0.007 (multivitamin)
What was measured: change in global cognition composite with cocoa extract (primary); with multivitamin (prespecified secondary)
What was found: Cocoa extract: mean z 0.03 (95% CI -0.02 to 0.08), P=0.28 [null]; multivitamin: mean z 0.07 (95% CI 0.02-0.12), P=0.007 [positive]; multivitamin effect with CVD history 0.14 (95% CI -0.02 to 0.31) vs no history 0.06 (0.01-0.11), interaction nominal P=0.01
Who was studied: US older adults (mean age 73; 60% women; 89% non-Hispanic White); ancillary to COSMOS
Limitations: Multivitamin was the secondary comparison; telephone-only testing; 89% non-Hispanic White; incident MCI/dementia not reduced (see cosmos-mind-2023-incidence row).
Replication: replicated
Source: Baker LD et al. Alzheimers Dement 2023;19(4):1308-1319 · 2023 · PubMed 36102337 · doi:10.1002/alz.12767
Meta-analysis: CPAP for OSA and cognition (14 RCTs)
Basis not stated
mixed
What was tried: CPAP treatment for obstructive sleep apnea vs control (sham/no CPAP), pooled from randomised trials
- 1,926 people
- For varied
- p = 0.025 (severe OSA attention/speed)
What was measured: cognitive domains: attention/processing speed, executive function, memory; subjective sleepiness
What was found: Attention/processing speed improved only in severe OSA: SMD 0.17 (95% CI 0.02-0.31), I2=0%; no significant effects in other domains or overall
Who was studied: Adults with OSA in 14 RCTs (pooled n=1926)
Limitations: POOLED estimate from heterogeneous short trials, not a single trial; mostly not dementia-risk populations; sleep-apnea treatment tagged 'sensory' as nearest schema category.
Replication: not-replicated
Source: J Alzheimers Dis 2020;75(3):705-715 · 2020 · PubMed 32310179 · doi:10.3233/JAD-200088
REWIND (dulaglutide; exploratory cognitive outcome)
Basis not stated
mixed
What was tried: Dulaglutide 1.5 mg subcutaneous weekly (GLP-1 receptor agonist) vs placebo; cognition assessed with MoCA and DSST at baseline and follow-up
- 9,901 people
- Ages >=50
- For median 5.4 years (IQR 5.1-5.9)
- p = 0.11 (unadjusted); 0.0018 (post-hoc adjusted)
What was measured: exploratory: first occurrence of substantive cognitive impairment (MoCA or DSST score >=1.5 SD below country baseline mean)
What was found: 4.05 vs 4.35 events per 100 patient-years; HR 0.93 (95% CI 0.85-1.02); after post-hoc adjustment for individual standardised baseline scores HR 0.86 (95% CI 0.79-0.95)
Who was studied: Adults >=50 with type 2 diabetes and additional cardiovascular risk factors at 371 sites in 24 countries; 9901 randomized (4949 dulaglutide, 4952 placebo); 8828 with baseline plus follow-up cognitive scores
Limitations: Exploratory analysis of a cardiovascular outcomes trial (cognition was not a primary endpoint); the prespecified unadjusted comparison was not significant and benefit appeared only after post-hoc adjustment; diabetes population only.
Replication: not-replicated
Source: Cukierman-Yaffe T et al. Lancet Neurol 2020;19(7):582-590 · 2020 · PubMed 32562683 · doi:10.1016/S1474-4422(20)30173-3
Show all 14 trials (10 shown so far)
These are listed on purpose. A change that did nothing in a properly run trial is as useful
to know as one that worked — it is the difference between spending your money and your energy well or badly.
US POINTER (Imaging Ancillary)
Basis not stated
null
What was tried: Same as US POINTER: structured vs self-guided multidomain lifestyle intervention; ancillary MRI/PET substudy
- 983 people
- Ages 60-79
- For 2 years
What was measured: 4 primary imaging outcomes: global beta-amyloid burden (PET), entorhinal cortex tau burden (PET), hippocampal volume, white matter hyperintensity volume
What was found: No intervention-group differences in longitudinal cognitive or imaging outcomes in the imaging subsample; lower baseline hippocampal volume associated with greater cognitive benefit of structured arm (lower HC: 0.077 SD, 95% CI 0.022-0.132; higher HC: 0.002 SD, 95% CI -0.037 to 0.041; interaction P=0.03); ERC tau-cognition association difference 0.289 (95% CI 0.029-0.550; interaction P=0.03)
Who was studied: US POINTER participants eligible for and consenting to neuroimaging (983 of 1943 assessed; 516 structured, 467 self-guided; 61.5% female; mean age 68.4)
Limitations: Subsample of parent trial (about half); 2-year window may be too short for biomarker change; no usual-care control.
Replication: ongoing
Source: Harrison TM et al. JAMA Neurol 2026;83(6):521-529 · 2026 · PubMed 42008251 · doi:10.1001/jamaneurol.2026.0832
evoke / evoke+
Basis not stated
null
What was tried: Oral semaglutide (GLP-1 receptor agonist) up to 14 mg once daily (flexible dose) vs placebo for up to 156 weeks
- 3,808 people
- Ages 55-85 (mean 72.2)
- For 104 weeks primary endpoint (treatment up to 156 weeks); trials discontinued for negative outcome
- p = 0.57 (evoke); 0.46 (evoke+)
What was measured: change in Clinical Dementia Rating-Sum of Boxes (CDR-SB) from baseline to week 104
What was found: Evoke: CDR-SB change 2.3 (SE 0.1) semaglutide vs 2.3 (0.1) placebo, estimated difference -0.08 (95% CI -0.35 to 0.20); evoke+: 2.2 vs 2.1, difference 0.10 (95% CI -0.17 to 0.38)
Who was studied: Amyloid-confirmed early symptomatic Alzheimer's disease (MCI or mild dementia due to AD), aged 55-85; evoke+ additionally allowed significant small-vessel pathology (54 participants, 2.8%); 566 sites in 40 countries
Limitations: Treatment trial in symptomatic AD, not a primary-prevention trial; observational GLP-1/dementia associations were not confirmed; TEAEs 91.2% semaglutide vs 84.8% placebo. NCT04777396, NCT04777409. Both trials discontinued.
Replication: not-replicated
Source: Lancet 2026;407(10544):2167-2179 (evoke and evoke+ investigators) · 2026 · PubMed 41865758 · doi:10.1016/S0140-6736(26)00459-9
ELAD
Basis not stated
null
What was tried: Daily subcutaneous liraglutide (GLP-1 receptor agonist) vs placebo for 52 weeks
- 204 people
- For 52 weeks
- p = 0.14 (primary)
What was measured: change in cerebral glucose metabolic rate (FDG-PET)
What was found: Primary FDG-PET difference -0.17 (95% CI -0.39 to 0.06), P=0.14; ADAS-Exec better with liraglutide 0.15 (95% CI 0.03-0.28), unadjusted P=0.01; ADCS-ADL -0.58 (95% CI -3.13 to 1.97), P=0.65; CDR-SB -0.06 (95% CI -0.57 to 0.44), P=0.81
Who was studied: Mild to moderate Alzheimer's disease syndrome, non-diabetic; multicentre UK phase 2b
Limitations: Phase 2b, small n, symptomatic AD (treatment, not prevention); secondary cognitive signal unadjusted for multiplicity. NCT01843075.
Replication: not-replicated
Source: Edison P et al. Nat Med 2026;32(1):353-361 (epub Dec 2025) · 2026 · PubMed 41326666 · doi:10.1038/s41591-025-04106-7
CBT-I in older adults with insomnia (NCT03954210)
Basis not stated
null
What was tried: Cognitive behavioural therapy for insomnia (CBT-I) vs control; assessments at baseline, 6 weeks and 1 year
- 200 people
- Ages older adults (not specified in abstract)
- For 1 year
- p = 0.78; 0.40; 0.77
What was measured: change in cognitive performance (processing speed, executive function, memory) and amyloid-beta burden (subsample n=50)
What was found: Processing speed mean difference 0.017 (95% CI -0.1036 to 0.1376), p=0.78; executive function -0.0881 (95% CI -0.2945 to 0.1182), p=0.40; memory 0.4068 (95% CI -2.3965 to 3.2101), p=0.77; no group difference in amyloid deposition
Who was studied: Cognitively normal older adults with insomnia symptoms
Limitations: 1-year follow-up too short for AD-risk outcomes per authors; small amyloid subsample; 'cognitive-training' tag used for a behavioural (CBT) intervention as closest schema category.
Replication: not-replicated
Source: Alzheimers Dement 2026;22(6):e71591 · 2026 · PubMed 42298279 · doi:10.1002/alz.71591
API ADAD Colombia Trial (crenezumab in PSEN1 E280A carriers)
Basis not stated
null
What was tried: Crenezumab (anti-amyloid-beta antibody) subcutaneous 300 mg then 720 mg every 2 weeks, later optional 60 mg/kg IV every 4 weeks, vs placebo, for 5-8 years in cognitively unimpaired mutation carriers; mutation non-carriers received placebo as a masked kindred control
- 252 people
- Ages 30-60
- For 5-8 years (common close); enrolled Dec 2013-Feb 2017, final data March 2022
- p = 0.43 (composite); 0.16 (FCSRT-CI)
What was measured: dual primary: annualised rate of change in API preclinical ADAD composite total score and in FCSRT Cueing Index
What was found: API ADAD composite annualised change -1.10 (SE 0.29) crenezumab vs -1.43 (0.29) placebo, difference 0.33 (95% CI -0.48 to 1.13); FCSRT-CI -0.03 vs -0.04, difference 0.01 (95% CI 0.00 to 0.02)
Who was studied: Cognitively unimpaired PSEN1 Glu280Ala (E280A) kindred members aged 30-60 in Medellin, Colombia; 85 crenezumab carriers, 84 placebo carriers, 83 placebo non-carriers; 63% women
Limitations: Single-centre, single-kindred phase 2 with 169 mutation carriers; crenezumab did not remove fibrillar amyloid, so the trial does not test plaque clearance; authors conclude robust fibrillar amyloid removal appears necessary for clinical efficacy.
Replication: not-replicated
Source: Tariot PN et al. Lancet Neurol 2026;25(2):147-159 · 2026 · PubMed 41579901 · doi:10.1016/S1474-4422(25)00426-0
EXERT
Basis not stated
null
What was tried: 18 months of supervised (first 12 months) moderate-high intensity aerobic training vs low-intensity stretching/balance/range-of-motion
- 296 people
- Ages 65-89 (per trial design; abstract states older adults)
- For 18 months
- p = 0.3
What was measured: global cognitive composite (ADAS-Cog-Exec) at 12 months
What was found: Aerobic vs stretching regression coefficient -0.078 (SE 0.074); no 12-month cognitive decline in either group; mean 12-month hippocampal volume loss 0.51% in both groups
Who was studied: Sedentary older adults with amnestic MCI; multicentre US phase 3
Limitations: No no-exercise control (both arms exercised, so absolute exercise effect unmeasured); the companion ADNI comparison (PMID 40271887) is non-randomised; age range stated from trial design rather than abstract.
Replication: not-replicated
Source: Baker LD et al. Alzheimers Dement 2025;21(4):e14586 · 2025 · PubMed 40271888 · doi:10.1002/alz.14586
AgeWell.de (Leipzig imaging substudy)
Basis not stated
null
What was tried: FINGER-based multimodal lifestyle intervention vs control
- 56 people
- Ages 60-77 (mean 68.8)
- For ~28 months between scans
What was measured: hippocampal volume, entorhinal cortex thickness, free water fraction, PSMD, WMH volume, grey-matter cerebral blood flow
What was found: No conclusive intervention effect on any marker; entorhinal thickness and free water declined MORE in intervention group in preregistered models but not after adjusting for baseline differences; exploratory: cerebral blood flow increased more in intervention group, associated with SBP reductions (no numeric estimates in abstract)
Who was studied: Leipzig AgeWell.de participants with 3T MRI before/after intervention (56 baseline, 41 follow-up; mean age 68.8)
Limitations: Very small (41 with follow-up), single site, smaller than planned; baseline imbalance.
Replication: not-replicated
Source: Beyer F et al. Neuroimage Clin 2025;46:103796 · 2025 · PubMed 40378769 · doi:10.1016/j.nicl.2025.103796
J-MINT
Basis not stated
null
What was tried: 18-month multidomain intervention: management of vascular risk factors + exercise + nutritional counselling + cognitive training vs control
- 531 people
- Ages 65-85
- For 18 months
What was measured: change in cognitive composite score over 18 months
What was found: Between-group difference in composite change 0.047 (95% CI -0.029 to 0.124)
Who was studied: Japanese community-dwelling older adults 65-85 with mild cognitive impairment
Limitations: MCI population (later stage than FINGER); 18 months; 24% attrition; subgroup findings exploratory.
Replication: not-replicated
Source: Sakurai T et al. Alzheimers Dement 2024;20(6):3918-3930 · 2024 · PubMed 38646854 · doi:10.1002/alz.13838
KEEPS Continuation (long-term cognitive follow-up of menopausal hormone therapy)
Basis not stated
null
What was tried: 4 years of oral conjugated equine estrogens 0.45 mg/d or transdermal estradiol 50 ug/d (each with cyclic micronized progesterone) vs placebo in the KEEPS trial (2005-2008), re-assessed ~10 years after trial completion (2017-2022)
- 275 people
- Ages recently postmenopausal at randomization (ages not given in abstract)
- For 4-year treatment + ~10-year post-trial follow-up (~14 years from randomization)
What was measured: cognitive performance (4 cognitive factor scores and global score) at ~10 years after trial end by original randomization arm
What was found: MHT allocation had no significant effect on cognitive slopes during KEEPS or across all years of follow-up in any domain; cross-sectional performance similar in oCEE, tE2 and placebo groups
Who was studied: Recently postmenopausal women (within 3 years of final menstrual period at randomization); 299 of 727 original participants enrolled at 7 of 9 sites, 275 with cognitive data at both time points
Limitations: Observational follow-up of 41% of the original randomized cohort (authors report similar baseline characteristics for returners vs non-returners); 7 of 9 sites; healthy population.
Replication: replicated
Source: Gleason CE et al. PLoS Med 2024;21(11):e1004435 · 2024 · PubMed 39570992 · doi:10.1371/journal.pmed.1004435
MIND Diet Trial
Basis not stated
null
What was tried: MIND diet (Mediterranean-DASH hybrid) with mild caloric restriction vs control diet with mild caloric restriction; both arms received dietary counselling and weight-loss support; 3 years
- 604 people
- Ages 65+
- For 3 years
- p = 0.23
What was measured: change from baseline in global cognition score and four domain scores (12-test battery)
What was found: Global cognition improved in both groups: +0.205 SD MIND vs +0.170 SD control; mean difference 0.035 SD (95% CI -0.022 to 0.092)
Who was studied: Cognitively unimpaired older adults with family history of dementia, BMI >25 and suboptimal diet; two US sites (Chicago, Boston)
Limitations: Control diet also involved counselling and caloric restriction (active comparator); both groups improved (practice effects/weight loss); age range not stated in abstract (65+ per trial design, from PMC). NCT02817074.
Replication: not-replicated
Source: Barnes LL et al. N Engl J Med 2023;389(7):602-611 · 2023 · PubMed 37466280 · doi:10.1056/NEJMoa2302368
Show all 31 trials (10 shown so far)
These trials found the intervention made an outcome worse. They are the strongest argument
for testing ideas rather than assuming them.
FINGER-NL (Netherlands)
Basis not stated
Not yet reported
What was tried: Multidomain lifestyle intervention (FINGER-adapted), 2 years
- 1,008 people
- Ages 60-79
- For 2 years
Who was studied: Cognitively healthy Dutch adults 60-79 with dementia prevention potential; 1008 included via Dutch Brain Research Registry campaign (13,795 registrants, 3475 eligible)
Limitations: No primary outcome publication located as of 2026-09-22; n reflects inclusions via the registry campaign only (total enrolment may differ).
Replication: ongoing
Source: Waterink L et al. Alzheimers Dement (N Y) 2025;11(1):e70017 (recruitment paper) · 2025 · PubMed 39790861 · doi:10.1002/trc2.70017
TRAILBLAZER-ALZ 3 (donanemab in preclinical AD)
Basis not stated
Not yet reported
What was tried: Donanemab IV monthly x9 infusions vs placebo, then clinical assessments every 6 months (decentralized design, plasma p-tau217 eligibility)
- 2,196 people
- Ages 55-80
- For 9 monthly infusions then event-driven follow-up
What was measured: time to clinical progression (time-to-event)
Who was studied: Adults 55-80 in the US and Japan with AD pathology detected by plasma p-tau217; 63,124 screened, 2196 enrolled (CDR-Global 0 n=1202; 0.5 n=664); mean baseline amyloid 63.2 centiloids (CDR 0) and 70.7 (CDR 0.5)
Limitations: Baseline/screening paper only; no efficacy results. Plasma p-tau217 eligibility rates differed by age, race and ethnicity (authors).
Replication: ongoing
Source: Yaari R et al. Alzheimers Dement 2025;21(9):e70662 (screening and baseline paper) · 2025 · PubMed 40955720 · doi:10.1002/alz.70662
AU-ARROW (Australia)
Basis not stated
Not yet reported
What was tried: Multimodal lifestyle (aerobic + resistance exercise, MIND diet advice, BrainHQ cognitive training, medical monitoring/health education) vs health education and coaching, 2 years
- 600 people
- Ages 55-79
- For 2 years
What was measured: change in global composite cognitive score
Who was studied: Australian adults 55-79
Limitations: Protocol only (planned n=600); no results located as of 2026-09-22.
Replication: ongoing
Source: Gardener SL et al. Alzheimers Dement (N Y) 2024;10(2):e12466 (protocol) · 2024 · PubMed 38596483 · doi:10.1002/trc2.12466
MET-FINGER
Basis not stated
Not yet reported
What was tried: FINGER 2.0 multidomain lifestyle (diet, physical activity, cognitive training, vascular/metabolic monitoring, social interaction) +/- metformin 1000-2000 mg/day (trial-within-trial, double-blind vs placebo) vs regular health advice
- 600 people
- Ages 60-79
- For 2 years
What was measured: change in global cognition (NTB)
Who was studied: APOE e4-enriched adults 60-79 at increased dementia risk; UK, Finland, Sweden
Limitations: Phase IIb proof-of-concept protocol; planned n=600; no results located as of 2026-09-22. NCT05109169.
Replication: ongoing
Source: Barbera M et al. Alzheimers Res Ther 2024;16(1):23 (protocol) · 2024 · PubMed 38297399 · doi:10.1186/s13195-023-01355-x
AHEAD 3-45 (lecanemab in preclinical AD)
Basis not stated
Not yet reported
What was tried: Lecanemab (BAN2401) IV, dose regimens tailored to baseline amyloid: A3 (intermediate amyloid ~20-40 centiloids, phase 2, PET endpoints) and A45 (elevated amyloid >40 centiloids, phase 3, cognitive composite primary) vs placebo, 4-year treatment
- 1,400 people
- Ages 55-80
- For 4 years treatment
What was measured: A45: change in cognitive composite (PACC5); A3: amyloid PET change
Who was studied: Cognitively unimpaired adults 55-80 with intermediate or elevated brain amyloid; plasma Abeta42/40 used to screen before PET; recruitment via TRC-PAD, ADNeT and J-TRC registries
Limitations: Design paper only; no results. ClinicalTrials.gov NCT04468659: phase 3, ACTIVE_NOT_RECRUITING, enrollment 1400 (ESTIMATED), start 2020-07-14, primary completion 2028-12-21 (registry loaded 2026-09-27).
Replication: ongoing
Source: Rafii MS et al. Alzheimers Dement 2023;19(4):1227-1233 (design paper; epub Aug 2022) · 2023 · PubMed 35971310 · doi:10.1002/alz.12748
SINGER (Singapore)
Basis not stated
Not yet reported
What was tried: Structured multidomain lifestyle (diet training, supervised then unsupervised exercise, cognitive training, vascular risk management) vs self-guided intervention, 2 years
- 1,200 people
- Ages 60-77
- For 2 years
What was measured: global cognition (modified Neuropsychological Test Battery)
Who was studied: Singapore adults 60-77 with CAIDE score >=6, >=1 LIBRA lifestyle risk, MoCA 18-27
Limitations: Protocol only; planned n=1200; no results located in PubMed as of 2026-09-22.
Replication: ongoing
Source: Xu X et al. J Prev Alzheimers Dis 2022;9(1):40-48 (protocol) · 2022 · PubMed 35098972 · doi:10.14283/jpad.2022.5
MIND-China (Multimodal INterventions to delay Dementia and disability in rural China)
Basis not stated
Not yet reported
What was tried: Multidomain lifestyle intervention (FINGER-adapted) in rural communities; intervention arm details not in the baseline paper
- 5,765 people
- Ages 60+ (mean 70.9)
Who was studied: Rural residents >=60 years, western Shandong province, China; 5765 completed baseline assessment (mean age 70.9; 57.2% women; 40.6% illiterate)
Limitations: No intervention outcome publication located in PubMed as of 2026-09-22 (search 'MIND-China[tiab]' returned baseline/cross-sectional papers only). the participant count is the baseline cohort, not necessarily the randomised sample.
Replication: ongoing
Source: Wang Y et al. Alzheimers Dement (N Y) 2022;8(1):e12254 (baseline paper) · 2022 · PubMed 35441085 · doi:10.1002/trc2.12254
Every figure in this section is a model output. It answers "what if this risk factor did not
exist in the population?" — a question no one has ever observed the answer to.