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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
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

Concentrating activity into one or two days worked about as well as spreading it across the week.

 Incident dementia cohort study 91,512 HR 0.73 (95% CI 0.60-0.89) for >300 min/week concentrated in 1-2 days vs <150 min/week Journal of Prevention of Alzheimer's Disease 2025
✓ Peer-reviewed PMID 40514301
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

Direction is for 12 weeks of cycle-ergometer exercise: putative glymphatic influx in the putamen and meningeal lymphatic vessel size and flow increased, and inflammation-related plasma proteins fell in step with the imaging changes. A mechanistic imaging result, not a cognitive outcome.

 MRI measures of glymphatic influx and meningeal lymphatic vessel size and flow, and plasma inflammatory proteins, after 12 weeks of cycling in healthy volunteers cohort study not stated not established — pubmed abstract reports no numeric effect size. Nature Communications 2025
✓ Peer-reviewed PMID 40204790
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

866 cases over a short follow-up for a disease with a long prodrome, so some of the association may be people already declining moving less.

 Incident all-cause dementia over a median 6.9 years cohort study 78,430 HR 0.49 (95% CI 0.39-0.62) at 9,826 steps/day vs lowest activity JAMA Neurology 2022
✓ Peer-reviewed PMID 36066874
Physical activity (general / dose) Exercise and activity Prevention Benefit
why

The largest effect for physical activity anywhere in this table by a wide margin. On 678 cases over 6.3 years, in a disease with a long prodrome, reverse causation is the more likely explanation for an effect that size.

 Incident dementia over a median 6.3 years cohort study 84,854 Trend across MVPA categories HR 0.66 (95% CI 0.62 to 0.70). "The lowest risk was identified in individuals who performed more than 1200 MET/min/week, those who had 84% (95% CI 0.12 to 0.21) lower risk of incident dementia compared to those who performed < 300 MET/min/week." BMC Medicine 2021
✓ Peer-reviewed PMID 34852818

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