Fish Oil Component May Hinder Brain Repair After Repeated Mild Injuries

A new study suggests that eicosapentaenoic acid (EPA), an omega-3 fatty acid found in fish oil, may interfere with the brain's ability to repair itself after repeated mild traumatic brain injuries. Researchers at the Medical University of South Carolina (MUSC) found that high levels of EPA were associated with weaker repair after injury in experimental models. This finding challenges the common perception of fish oil as universally beneficial for brain health.

The research, published in the journal *Cell Reports*, focused on the biological processes involved in repairing brain blood vessels. The team, led by neuroscientist Onder Albayram, Ph.D., investigated how long-term fish oil use influenced the brain's response to repeated mild head impacts in mice. They also studied human brain microvascular endothelial cells, which form part of the blood-brain barrier. In these cells, EPA, but not docosahexaenoic acid (DHA), was linked to reduced repair capacity.

The study also analyzed postmortem brain tissue from individuals diagnosed with chronic traumatic encephalopathy (CTE) who had a history of repeated brain injury. These analyses revealed evidence of disrupted fatty acid balance and transcriptional changes affecting vascular and metabolic pathways. This suggests a potential link between altered lipid handling and reduced vascular stability in chronic brain disease.

Albayram emphasized that the study does not issue a blanket warning against fish oil. He stated that biology is context-dependent. The research highlights the need to understand how these supplements behave in the body over time. The experiments focused on a specific scenario: repeated mild brain injury. The CTE tissue provided supporting observations, not direct proof of cause and effect.

The researchers plan to continue investigating how EPA is absorbed, transported, and distributed in the body. They are particularly interested in the mechanisms controlling fatty acid movement. This research aims to contribute to a more nuanced understanding of omega-3 supplementation and its effects on brain health.