Fish intake and cognitive decline, dementia and Alzheimer's disease
What it found
In 35 observational studies, people who ate the most fish were less likely to develop cognitive impairment, dementia or Alzheimer's disease than those who ate the least.
The link was strongest for cognitive impairment, where risk fell as fish intake rose.
What they found
Studies in people
Cognitive impairment and decline
People who ate the most fish were 18% less likely to have cognitive impairment or decline than those who ate the least. In the dose-response analysis, risk fell by up to 30% at 150 g of fish per day.
All types of dementia
The highest fish eaters were 18% less likely to develop dementia than the lowest fish eaters. The dose-response analysis did not find a significant link for dementia.
Alzheimer's disease
People who ate the most fish were 20% less likely to develop Alzheimer's disease than those who ate the least. The dose-response analysis found a lower risk up to 50 g of fish per day, but no significant link overall.
APOE gene variant
Results by APOE genotype were mixed. One study found a lower risk of cognitive impairment among APOE ε4 carriers who ate more fish, but pooled results for dementia showed no significant link.
Other findings
Study quality and design
Most studies were prospective, and the overall quality was good. The authors note that observational studies can only show associations, not cause and effect.
What the authors conclude
“Current findings suggest fish consumption is associated with a lower risk of cognitive impairment/decline in a dose-response manner, while for dementia and Alzheimer's disease there is a need for further studies to improve the strength of evidence.”
Also in their conclusions
- They say higher fish intake may be associated with better cognitive status in older individuals.
- They state that whether fish consumption actually decreases the risk of dementia and Alzheimer's disease is still to be confirmed, but current results are promising.
- They advise that further studies are needed to understand the role of fish intake in more complex conditions and to see whether benefits come from omega-3 or other compounds.
How it was done
Cognitive impairment is expected to affect a large share of the ageing population, and lifelong diet habits are thought to play a role in preventing cognitive decline. Fish has been widely studied for its potential effects on the human brain.
The authors pooled 35 observational studies, mostly in older adults, covering about 849,263 people. The studies looked at cognitive impairment or decline, all types of dementia, and Alzheimer's disease, and compared the highest with the lowest fish consumption.
What it can’t tell you
- These were observational studies, so they can show a link between fish intake and cognitive outcomes, but not that fish causes the lower risk.
- Most studies relied on people reporting their own fish consumption, which can be inaccurate.
- The authors say more research is needed to confirm the findings for dementia and Alzheimer's disease.
Who paid
- Conflicts
- A.D. is an employee of Bolton Food S.P.A. The other authors have no competing interests to disclose.
- Authors work at
- University of Catania, Italy; Jagiellonian University Medical College, Poland; Laboratory of Pharmacoepidemiology and Human Nutrition, Italy
The paper
- Title
- Fish consumption, cognitive impairment and dementia: an updated dose-response meta-analysis of observational studies
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Godos J, Micek A, Currenti W, et al (2024). Fish consumption, cognitive impairment and dementia: an updated dose-response meta-analysis of observational studies. Aging clinical and experimental research. doi:10.1007/s40520-024-02823-6Free full textPubMed 39162889DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error