Research
Hormonal
High DHA fish oil supplementation slows the rate of cognitive decline in older adults, although its effects on depression disorders remain unclear.
For older adults concerned about memory loss, high DHA fish oil (where DHA is higher than EPA) may help slow cognitive decline. However, do not expect it to treat depression, as evidence for that is currently unclear.
ModerateQualifiesMEDIUM confidence
DHA has also been reported to be effective in slowing the rate of cognitive decline, while its possible effects on depression disorders are still unclear. Johnson et al. (2008) tested the low dietary intake of DHA and/or foods rich in lutein on cognitive decline in the elderly.
Why this rating
The paper notes 'inconclusive results' and 'inconsistent outcomes' in several instances, and specifically states effects on depression are 'unclear'.
Source
How does high DHA fish oil affect health? A systematic review of evidence
Samaneh Ghasemi Fard et al. · Critical Reviews in Food Science and Nutrition · 2018
DOI 10.1080/10408398.2018.1425978
systematic_reviewCited 242×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
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- High DHA fish oil supplementation (DHA > EPA) improves cardiovascular efficiency during submaximal exercise by lowering heart rate and improving heart rate variability, without negatively affecting endurance performance.Good
- High DHA fish oil supplementation improves postprandial arterial stiffness and endothelial function, potentially reducing cardiovascular disease risk, whereas EPA alone may not provide the same postprandial benefit.Good
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