A study led by the Medical University of South Carolina, published on Apr. 7 in Cell Reports, suggests that fish oil supplements may impair recovery after repetitive mild traumatic brain injuries rather than help as previously believed.
The research comes at a time when demand for omega-3 fatty acids found in fish oil is increasing and these supplements are being added to various foods and drinks. This has raised public interest in their effects on health, especially regarding brain injury and recovery.
Onder Albayram, Ph.D., associate professor at MUSC and lead investigator, 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." He added that the study is the first to examine whether the brain is resilient or resistant to such supplementation. The team investigated how long-term use of fish oil affected biological pathways related to cerebrovascular repair following injury. They focused particularly on eicosapentaenoic acid (EPA), an omega-3 fatty acid commonly found in these supplements.
Their findings showed that higher levels of EPA in the brain were linked with reduced capacity for tissue repair after injury. In mouse models exposed to repeated mild head impacts, those given long-term fish oil supplementation had poorer neurological performance over time and more evidence of vascular-associated tau accumulation—a marker associated with neurovascular dysfunction. Albayram said, "In a sensitive brain state modeled in mice, long-term fish oil supplementation revealed a delayed vulnerability... linking impaired recovery to neurovascular dysfunction and perivascular tau pathology." Further experiments using human brain microvascular endothelial cells showed EPA was associated with weaker endothelial repair functions compared to another omega-3 fatty acid found in fish oil called DHA.
To connect these results with human disease context, researchers also analyzed postmortem tissue from chronic traumatic encephalopathy (CTE) cases. They observed disrupted fatty acid balance and changes affecting vascular stability similar to those seen in animal studies. Albayram cautioned against generalizing the findings: "I am not saying fish oil is good or bad in some universal way... We need to understand how these supplements behave in the body over time." He emphasized that biology is context-dependent and more research is needed before making broad recommendations about supplement use.
The team plans further studies focusing on how EPA is processed within the body. Albayram concluded: "This paper is a starting point... it opens a new conversation about precision nutrition in neuroscience."
