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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 5 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, 5 rows. Every row links to its source.
Exposure Question Direction Outcome measured Design People Effect size, as the source reported it Source
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

The authors call the association weak (RR 0.97), and it was absent beyond 10 years of follow-up.

 Cognitive impairment or decline meta-analysis 341,471 Pooled RR 0.97 (95% CI 0.97-0.99) for cognitive impairment/decline; no association beyond 10 years of follow-up JAMA Network Open 2024
✓ Peer-reviewed PMID 38300618
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

Pooled across 29 cohorts. The association weakened to HR 0.85 after maximal confounder adjustment and was not significant for low-intensity activity.

 Incident Alzheimer's disease meta-analysis 2,068,519 Pooled HR 0.72 (95% CI 0.65-0.80) overall; HR 0.85 (95% CI 0.79-0.91) after maximal confounder adjustment; high-intensity activity HR 0.56 (95% CI 0.45-0.68); moderate-intensity HR 0.85 (95% CI 0.80-0.93); low-intensity HR 0.94 (95% CI 0.77-1.15, not significant) Ageing Research Reviews 2023
✓ Peer-reviewed PMID 37979700
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

The authors state the association held in longer follow-ups, which is their answer to the reverse-causation objection raised by the Whitehall II cohort.

 Incident all-cause dementia and Alzheimer's disease meta-analysis 257,983 Pooled RR 0.80 (95% CI 0.77-0.84) for all-cause dementia British Journal of Sports Medicine 2022
✓ Peer-reviewed PMID 35301183
Physical activity (general / dose) Exercise and activity Treatment Benefit
why

Pools 27 small trials in people who already have dementia, and reports a much larger effect (SMD 0.69) than the single largest such trial, DAPA, which found none.

 Cognitive function meta-analysis 2,242 SMD 0.691 (95% CrI 0.373-1.039) at 650 MET-min/week; aerobic SMD 0.909 (0.495-1.362) at 660 MET-min/week BMC Geriatrics 2024
✓ Peer-reviewed PMID 38824515
Resistance training Exercise and activity Prevention Benefit
why

Seven small trials; working memory did not improve (P=0.14).

 General cognitive function and executive function meta-analysis not stated General cognition SMD 0.53 (P=0.04); executive function SMD 0.50 (P=0.0003) International Journal of Sports Medicine 2020
✓ Peer-reviewed PMID 32599643

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