Fish Oil Supplement Linked to Slower Brain Repair in Certain Populations, Study Finds
Fish oil has long been marketed as the go-to supplement for brain health, thanks to its high levels of omega-3 fatty acids. But a new animal study published in Cell Reports suggests there may be certain caveats. Researchers focused on EPA, one of the primary omega-3s in fish oil, and found it may actually interfere with how the brain heals itself after an injury.
To figure out what’s actually happening beneath the surface, researchers examined how long-term fish oil use impacted the brain's response to repeated mild head impacts in mice. Under normal conditions, EPA gradually builds up in the brain. But after repeated head injuries, researchers found that EPA levels drop sharply, suggesting the brain is rapidly using it during injury. The loss of EPA was linked to damage in blood vessels, reduced repair capacity, and overall poorer brain blood flow.
"In a sensitive brain state modeled in mice, long-term fish oil supplementation revealed a delayed vulnerability," said lead author Onder Albayram, PhD, a neuroscientist and associate professor at the Medical University of South Carolina, per a press release. "The animals showed poorer neurological and spatial learning performance over time, together with clear evidence of vascular-associated tau accumulation in the cortex, linking impaired recovery to neurovascular dysfunction and perivascular tau pathology."
Researchers also examined postmortem brain tissue from humans diagnosed with chronic traumatic encephalopathy (CTE) and a history of repeated brain injury. The same patterns showed up, finding similar issues with blood vessels and metabolism.
"I am not saying fish oil is good or bad in some universal way," Albayram clarified. "What our data highlights is that biology is context-dependent. We need to understand how these supplements behave in the body over time, rather than assuming the same effect applies to everyone."
It’s also worth noting that since much of the data came from mouse models, effects may vary for humans. And because the research focuses on "repeated mild head injuries," the findings may not apply to individuals supplementing with fish oil for general health, like cardiovascular support, without a history of head trauma.