The Study
The association between omega-3 supplementation and cognitive decline in older adults
This study watched people over time and noticed that those who took omega-3 supplements tended to forget things faster than those who didn’t. But it didn’t make people take the supplements—it just recorded what they already did. So we can’t say the supplements caused the memory loss, just that they happened together.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Some older people take omega-3 fish oil pills to protect their memory, but this study found that those who took them actually forgot things faster.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 540 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1These changes are small per year but add up over time and are similar in size to early Alzheimer’s progression, meaning they could matter for daily life.
- 2People taking omega-3s had 0.266 points worse MMSE scores, 0.823 points higher ADAS-Cog13 scores, and 0.205 points higher CDR-SB scores each year compared to non-users.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The Journal of Prevention of Alzheimer's Disease
Year
2026
Authors
Zheng Liao, Zi-cheng Hu, G. Zeng, Jia Chen, Xin-Peng Li, Yu-Hui Liu, X. Yao, Ye-Ran Wang
Related Content
Claims (7)
When the brain uses less sugar for energy, older people tend to forget things or think more slowly than they used to.
Taking omega-3 supplements doesn't seem to make any difference in the brain changes that happen with mild memory problems in older people.
Taking omega-3 supplements might be linked to a faster drop in brain energy use in areas affected by Alzheimer’s, and this could explain up to 40% of why some older adults’ memories and thinking skills get worse over time.
Taking omega-3 supplements doesn't seem to change the brain changes usually seen in Alzheimer's disease, like plaque buildup or brain shrinkage, in older people over five years.
Taking omega-3 supplements might be linked to older people's memory and thinking skills getting worse faster, according to some tests doctors use to check brain function.
Some scientists think that taking omega-3 supplements might hurt memory or thinking in older people because these fats can break down in a way that damages the energy supply in brain cells.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.