New Study Examines Potential Brain Risks Associated With Fish Oil Intake

What if a supplement many consider "brain-friendly" could backfire under certain conditions? New research from the Medical University of South Carolina suggests that fish oil, widely consumed for its omega-3 benefits, may actually hinder brain recovery after repeated mild injuries.

Published in Cell Reports, the study explored how omega-3 fatty acids influence the brain’s ability to repair itself, particularly after traumatic events. While compounds like docosahexaenoic acid (DHA) are known to support brain structure and function, the researchers identified a potential issue with another major component of fish oil: eicosapentaenoic acid (EPA).

Using experimental models, the team found that elevated levels of EPA were linked to impaired repair of blood vessels in the brain. This is significant because recovery from brain injury relies heavily on restoring vascular integrity. When this process is disrupted, it can lead to longer-term complications, including cognitive decline.

The findings also highlighted a concept known as “context-dependent vulnerability.” In simple terms, fish oil may not have uniform effects across all situations. In the case of repeated mild traumatic brain injury—similar to what athletes or accident victims may experience—EPA appeared to interfere with the brain’s natural healing mechanisms. Mice exposed to long-term fish oil supplementation showed poorer neurological performance and signs of vascular instability over time.

Further laboratory studies on human brain cells supported these observations. EPA, unlike DHA, reduced the ability of endothelial cells to repair and form stable networks, a key step in healing damaged brain tissue.

Importantly, the researchers caution against generalizing these findings. Fish oil is not universally harmful, but its effects may vary depending on individual biology, injury status, and overall health.

As scientists continue to unravel how nutrients interact with complex systems like the brain, one message is clear: even widely trusted supplements deserve a closer, more personalized look.

REFERENCE: Eda Karakaya, Burak Berber, Onur Eskiocak, Jazlyn Edwards, Randy Bent Barker, Sarah Jamil, Weiguo Li, Yasir Abdul, Maria Ericsson, Thor Stein, Ann McKee, Adviye Ergul, Semir Beyaz, Onder Albayram. Eicosapentaenoic acid reprograms cerebrovascular metabolism and impairs repair after brain injury, with relevance to chronic traumatic encephalopathy. Cell Reports, 2026; 117135 DOI: 10.1016/j.celrep.2026.117135