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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
Modifiable risk factors combined All modifiable factors together Prevention Harm
why

Direction is for carrying the risk factors. The weighted combined estimate (32.0% for seven factors) is lower than the Lancet Commission's 45% for 14.

 Population attributable fraction of dementia meta-analysis not stated Weighted combined PAF 32.0% (95% CI 26.6-37.5) for seven modifiable factors Lancet Healthy Longevity 2024
✓ Peer-reviewed PMID 38824956
Peripheral diseases combined (population attributable fraction) All modifiable factors together Prevention Harm
why

Direction is for carrying the peripheral diseases: together they were related to about one-third of global dementia burden, led by periodontal disease, chronic liver disease, hearing loss, vision loss and type 2 diabetes. Attributable fractions assume the pooled associations are causal.

 Population attributable fraction of global dementia burden for 16 peripheral diseases meta-analysis not stated Globally, these peripheral diseases collectively were related to a combined PAF of 33.18% (95% confidence interval (CI) 16.80-48.43) of dementia burden, corresponding to 18.8 million prevalent cases. The leading ten PAF contributors were periodontal diseases (6.10%, 95% CI 0.95-10.28), cirrhosis and other chronic liver diseases (5.51%, 95% CI 1.77-8.86), age-related and other hearing loss (4.70%, 95% CI 3.51-6.06), blindness and vision loss (4.30%, 95% CI 3.43-5.05), type 2 diabetes mellitus (3.80%, 95% CI 3.06-4.53) Nature human behaviour 2026
✓ Peer-reviewed PMID 41559195
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 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

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