Common Dietary Supplement May Have an Unexpected Effect on the Brain

Follow-up - Al-Wasat Iraqi newspaper

A new study raises questions about the effect of some components of fish oil supplements on the brain, after researchers found that eicosapentaenoic acid (EPA) may impede brain repair after head injuries.

The study, conducted on mice that suffered mild head injuries, showed that animals fed a diet containing EPA (one of the omega-3 fatty acids) performed worse on spatial memory and learning tests after the injury, compared with mice that were not on the same diet.

Researchers suggest EPA may affect the ability of the brain's blood vessels to recover by altering how cells use energy, potentially directing some of their resources away from repair processes.

The same effect did not appear with docosahexaenoic acid (DHA), another omega-3 fatty acid known for its role in building and maintaining brain cells. In follow-up experiments using human cells taken from the brain's microvasculature, DHA did not complicate repair processes as EPA did.

Neuroscientist Onder Alperam from the Medical University of South Carolina said fish oil supplements "are everywhere, people take them for many reasons, and often without a clear understanding of their long-term effects."

The researchers also found that EPA, not DHA, accumulated in the brains of the mice that took the supplements, and EPA's effect on the vasculature was associated with accumulation of tau proteins, which are linked to brain cell damage and some neurodegenerative diseases.

To assess how these findings relate to humans, the researchers analyzed tissue samples from the brains of people who had chronic traumatic encephalopathy (CTE), a condition associated with repeated head injuries, and found that the tissues showed some of the metabolic disturbances and vascular changes observed in the mouse experiments.

However, the researchers emphasize that these results do not mean fish oil supplements cause chronic traumatic encephalopathy in humans, since most of the study's evidence comes from animal and cell experiments, and clinical studies are still needed to determine whether the same effects occur in people.

Neuroscientist Onur Eskiocak from the Cold Spring Harbor laboratory said, "The idea that fish oil gives broad, uniform benefits to everyone does not hold up once you begin studying complex biochemical interactions," adding: "But that does not mean it is harmful to your health."

The researchers intend to continue studying the effects of EPA and DHA in different types of brain cells and regions, ahead of conducting clinical studies at later stages.

Source: Agencies