Scientists Link EPA in Omega 3 Fish Oil to Worse Mouse Recovery
A study found that omega 3 fish oil ingredients containing EPA were linked to worse memory and learning after mild traumatic head injuries in mice. The effect appeared in injured brains in repair mode, not in uninjured animals.
Onder Albayram, a neuroscientist at the Medical University of South Carolina, said, "Fish oil supplements are everywhere, and people take them for a range of reasons, often without a clear understanding of their long-term effects," and added, "But in terms of neuroscience, we still don't know whether the brain has resilience or resistance to this supplement. That's why ours is the first such study in the field."
EPA and brain repair
The mice were fed diets containing EPA before they were given mild traumatic head injuries, and they later performed worse on spatial memory and learning tasks. The researchers said EPA may get in the way of blood vessel repair by reprogramming metabolic activity, and they described the effect as a context-dependent metabolic vulnerability.
In the same work, EPA accumulated in the brains of mice fed the supplements. The destabilizing effects on blood vessels were linked to a build-up of toxic tau proteins tied to brain degeneration.
DHA in follow-up tests
Follow-up experiments using human-derived brain microvascular endothelial cells did not show the same interference from DHA. The researchers also found that DHA is more readily built into brain cell membranes than EPA, which helped separate the two ingredients in their tests.
Onur Eskiocak, a neuroscientist at Cold Spring Harbor Laboratory, said, "This idea of fish oil being a one-size-fits-all benefit doesn't work once you start investigating interactions," and added, "But that doesn't mean it's bad for you."
Human tissue and CTE
A further analysis of human brain tissue from individuals affected by chronic traumatic encephalopathy showed a similar kind of metabolic disruption and blood vessel damage. The researchers speculated that fish oil supplements containing EPA may increase the risk of CTE if they worsen the effects of mild concussions.
The bulk of the evidence came from animal and cell experiments, so the practical takeaway is narrower than a blanket warning: the concern centered on EPA in a specific injury setting, while DHA did not show the same effect in the follow-up tests.
