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Home › Research › What the research found › Every row

Every row of the evidence table

One row per finding: what was tested, which way the result went, and how the study was built. The answer by area, and where the studies disagree, are on the main page.

Every row

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Area All 382 Care, carers and services 140 Medicines 85 Genes (not modifiable) 35 All modifiable factors together 27 Diet and supplements 23 Exercise and activity 21 Sleep, mood and social life 19 Hearing and vision 8 Alcohol, tobacco and cannabis 6 Infection and vaccination 5 Heart and metabolic health 4 Injury, delirium and falls 4 Environment 3 Cognitive activity 2
Question Both Prevention 190 Treatment 192
Direction Any Benefit 144 Harm 105 No effect 38 Mixed 37 No direction reported 58
Design Any meta-analysis 57 randomised trial 44 phase 3 trial 15 systematic review 9 phase 2 trial 10 cohort study 136 phase 1 trial 2 cross-sectional study 31 case-control study 14 modelling study 20 regulatory decision 7 company announcement 1 coverage determination 1 None 35
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Showing 4 of 382 rows. One row per study per exposure: a study that tested two different things appears twice, once for each.

Scroll the table sideways to see every column.

Research and outcomes, 4 rows. Every row links to its source.
Exposure Question Direction Outcome measured Design People Effect size, as the source reported it Source
Birth cohort and calendar period (secular trend in dementia) All modifiable factors together Prevention Benefit
why

Direction is for more recent birth cohort: after controlling for age and period, later-born cohorts were less likely to have dementia in all three regions, more so among women; the point estimates for men in England were not significant.

 Age-specific dementia prevalence by birth cohort in the US, Europe and England cross-sectional study 62,437 point estimate for 1944-1948 vs 1919-1923 cohorts: US, -0.55 [95% CI, -0.77 to -0.34] vs -0.18 [95% CI, -0.25 to -0.10]; Europe, -1.49 [95% CI, -1.72 to -1.27] vs -0.24 [95% CI, -0.35 to -0.13]; and England, -0.48 [95% CI, -0.89 to -0.08] vs -0.23 [95% CI, -0.38 to -0.07] JAMA Network Open 2025
✓ Peer-reviewed PMID 40455442
Birth cohort and calendar period (secular trend in dementia) All modifiable factors together Prevention Benefit
why

Direction is for the later survey year: prevalence fell from 11.6% to 8.8%, with rising education associated with some of the decline despite a worse cardiovascular risk profile.

 Dementia prevalence among US adults 65+, 2000 versus 2012 cross-sectional study 21,057 Dementia prevalence among those 65 years or older decreased from 11.6% (95% CI, 10.7%-12.7%) in 2000 to 8.8% (95% CI, 8.2%-9.4%) (8.6% with age- and sex-standardization) in 2012 (P < .001) JAMA Internal Medicine 2017
✓ Peer-reviewed PMID 27893041
Birth cohort and calendar period (secular trend in dementia) All modifiable factors together Prevention Benefit
why

Direction is for the later-born population: prevalence was 6.5% against the 8.3% expected from the earlier study (odds ratio 0.7), which the authors read as a cohort effect.

 Dementia prevalence at age 65+ in three English areas, CFAS II (2008-11) versus CFAS I (1989-94) cross-sectional study 15,431 Using CFAS I age and sex specific estimates of prevalence in individuals aged 65 years or older, standardised to the 2011 population, 8·3% (884,000) of this population would be expected to have dementia in 2011. However, CFAS II shows that the prevalence is lower (6·5%; 670,000), a decrease of 1·8% (odds ratio for CFAS II vs CFAS I 0·7, 95% CI 0·6-0·9, p=0·003) The Lancet 2013
✓ Peer-reviewed PMID 23871492
Sex differences (biological sex as exposure) All modifiable factors together Prevention Harm
why

Direction is for female sex: women had higher odds of a high neuritic plaque burden than men after adjustment, and were more likely to reach Braak stage V-VI. Black non-carriers and non-carriers of African ancestry were least likely to have high plaque burden, a protection weakened in ε4 carriers.

 Neuritic plaque burden (CERAD score) at autopsy by sex, and its interaction with APOE ε4, race and African ancestry cross-sectional study 2,268 Female individuals had higher plaque burden than male individuals (unadjusted odds ratio [OR], 1.97; 95% CI, 1.67-2.29; P < .001), and this association remained significant in adjusted models for sociodemographic and vascular factors and APOEε4 status (adjusted OR, 1.65; 95% CI, 1.33-2.20; P < .001). APOEε4 carriers of both sexes had an approximately 4-fold greater odds of plaques JAMA neurology 2026
✓ Peer-reviewed PMID 41729539

How this table was built, and where it is weak →