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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 1 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, 1 row. Every row links to its source.
Exposure Question Direction Outcome measured Design People Effect size, as the source reported it Source
Omega-3 / fish and fish oil Diet and supplements Prevention No effect
why

Risk ratios close to one across every intake strategy, including substituting fish for meat. This is the one study here that emulates a trial rather than comparing eaters with non-eaters, and it disagrees with the pooled cohorts.

 21-year Alzheimer's disease risk cohort study 2,012 21-year Alzheimer's risk 10.33% (no fish) vs 9.98% (3+ servings/week); risk ratios near 1 American Journal of Epidemiology 2026
✓ Peer-reviewed PMID 42506897

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