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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 6 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, 6 rows. Every row links to its source.
Exposure Question Direction Outcome measured Design People Effect size, as the source reported it Source
Population burden (prevalence, incidence, lifetime risk) All modifiable factors together Prevention No direction reported
why

A burden-of-disease decomposition: age-standardised rates rose slightly and population growth was the largest driver of the rise in cases. It compares no exposure, so no direction is recorded.

 Global prevalence, incidence, mortality and DALYs of young-onset dementia, 1990-2021 modelling study not stated Global age standardized prevalence and incidence of dementia among people under 65 years increased from 93.39 and 16.24 per 100,000 persons in 1990 to 96.09 and 17.16 per 100,000 persons in 2021; mortality increased from 0.89 per 100,000 population to 0.91 per 100,000 population; and age standardized DALYs increased from 45.60 per 100,000 persons to 46.78 per 100,000 persons Translational Psychiatry 2025
✓ Peer-reviewed PMID 39966345
Population burden (prevalence, incidence, lifetime risk) All modifiable factors together Prevention No direction reported
why

A lifetime-risk estimate (42% after age 55, higher in women, Black adults and APOE4 carriers) and a projection of new cases. It compares no exposure, so no direction is recorded.

 Lifetime risk of dementia from age 55, and projected annual US incident cases to 2060 cohort study 15,043 The lifetime risk of dementia after age 55 years was 42% (95% confidence interval: 41-43). Rates were substantially higher in women, Black adults and APOE ε4 carriers, with lifetime risks ranging from approximately 45% to 60% in these populations. The number of US adults who will develop dementia each year was projected to increase from approximately 514,000 in 2020 to approximately 1 million in 2060 Nature Medicine 2025
✓ Peer-reviewed PMID 39806070
Population burden (prevalence, incidence, lifetime risk) All modifiable factors together Prevention No direction reported
why

A pooled incidence and prevalence estimate with no exposure compared, so no direction is recorded.

 Pooled incidence and prevalence of frontotemporal dementia meta-analysis not stated Pooled crude incidence for FTD was 2.28 (95% CI, 1.55-3.36) per 100 000 person-years and prevalence, 9.17 (95% CI, 3.59-23.42) per 100 000 people JAMA Neurology 2025
✓ Peer-reviewed PMID 40920400
Population burden (prevalence, incidence, lifetime risk) All modifiable factors together Prevention No direction reported
why

A prevalence estimate and forecast: cases are projected to rise from 57.4 million to 152.8 million while age-standardised prevalence stays flat, with the rise attributed to population growth and ageing. It compares no exposure, so there is no direction to record.

 Number of people with dementia worldwide, 2019 and forecast to 2050 modelling study not stated We estimated that the number of people with dementia would increase from 57·4 (95% uncertainty interval 50·4-65·1) million cases globally in 2019 to 152·8 (130·8-175·9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0·1% [-7·5 to 10·8]) The Lancet Public Health 2022
✓ Peer-reviewed PMID 34998485
Population burden (prevalence, incidence, lifetime risk) All modifiable factors together Prevention No direction reported
why

A pooled prevalence estimate with no exposure compared, so there is no direction to record.

 Global prevalence of young-onset dementia (ages 30-64) meta-analysis 2,760,379 Age-standardized prevalence estimates increased from 1.1 per 100 000 population in the group aged 30 to 34 years to 77.4 per 100 000 population in the group aged 60 to 64 years. This gives an overall global age-standardized prevalence of 119.0 per 100 000 population in the age range of 30 to 64 years, corresponding to 3.9 million people aged 30 to 64 years living with YOD in the world JAMA Neurology 2021
✓ Peer-reviewed PMID 34279544
Sex and gender differences (research agenda) All modifiable factors together Prevention No direction reported
why

A position paper from an expert network. It sets out 12 priority research areas on sex and gender in Alzheimer's disease and reports no effect estimate.

 None measured (research agenda) None not stated not established — position paper; the abstract reports no effect estimate. Alzheimer's & Dementia 2018
✓ Peer-reviewed PMID 29907423

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