Fish oil supplements, a popular choice for brain health, may have an unexpected downside, according to a recent study. The research, conducted on mice with mild traumatic head injuries, suggests that one of the omega-3 fatty acids found in fish oil supplements, EPA (eicosapentaenoic acid), could interfere with the brain's repair processes. This finding challenges the widely held belief that omega-3s are universally beneficial for brain health.
The study revealed that mice fed with diets containing EPA performed worse on spatial memory and learning tasks after sustaining mild traumatic head injuries. Interestingly, the omega-3 fatty acid DHA (docosahexaenoic acid), known for its role in building and maintaining brain cells, did not exhibit similar harmful effects in subsequent experiments using human-derived brain cells.
Neuroscientist Onder Albayram from the Medical University of South Carolina (MUSC) highlights the significance of this study, stating, "Fish oil supplements are prevalent, and people consume them for various reasons, often without fully understanding their long-term impact. Our research is the first to explore the brain's resilience or resistance to these supplements, making it a groundbreaking contribution to the field."
The researchers coined the term "context-dependent metabolic vulnerability" to describe the observed effects. This phenomenon suggests that EPA might divert energy away from brain repair under certain conditions, particularly in injured mouse brains. The study also noted that EPA accumulated in the brains of mice fed these supplements, which is consistent with DHA's higher incorporation into brain cell membranes.
Furthermore, the destabilizing effects of EPA on blood vessels led to the buildup of toxic tau proteins, associated with brain degeneration. This finding was supported by an analysis of human brain tissue from individuals with chronic traumatic encephalopathy (CTE), a condition linked to repeated head injuries. The researchers speculate that fish oil supplements containing EPA may increase the risk of CTE by exacerbating the effects of mild concussions, which can go unnoticed.
However, the study emphasizes the need for further investigation. While the evidence points to potential associations, it primarily stems from animal and cell experiments. Neuroscientist Onur Eskiocak from Cold Spring Harbor Laboratory notes, "The idea of fish oil being a universal panacea doesn't hold up under scrutiny. However, this doesn't imply that it is detrimental."
The researchers plan to expand their studies, examining the effects of EPA and DHA on various brain cell types and regions. Clinical trials could be the next step, according to Albayram, who believes this research opens up a new avenue for precision nutrition in neuroscience, encouraging the field to ask more targeted questions.
