Fish oil may be hurting your brain, new study finds
Science News
from research organizations
Fish oil may be hurting your brain, new study finds
Date:
April 26, 2026
Source:
Medical University of South Carolina
Summary:
Fish oil has long been praised as brain-boosting, but new research suggests the story may be more complicated. Scientists found that in people with repeated mild head injuries, a key omega-3 fatty acid in fish oil—EPA—may actually interfere with the brain’s ability to repair itself. Instead of helping recovery, it appears to weaken blood vessel stability, disrupt healing signals, and even contribute to harmful protein buildup linked to cognitive decline.
Share:
FULL STORY
Fish oil might not be the brain booster people think—under certain conditions, it could even hinder recovery. Credit: Shutterstock
A new study from the Medical University of South Carolina is raising fresh concerns about fish oil supplements, especially for people who experience repeated mild traumatic brain injuries. Writing in the journal Cell Reports, researchers report that these widely used supplements, often promoted as protective for the brain, could actually interfere with healing after injury.
The research was led by neuroscientist Onder Albayram, Ph.D., an associate professor at MUSC and a member of the National Trauma Society Committee. His team focused on the biological processes involved in repairing blood vessels in the brain after injury.
Rising Popularity of Omega-3 Supplements
Interest in omega-3 fatty acids, the key components of fish oil, has been growing rapidly. According to Fortune Business Insights, these supplements are now appearing not only in capsules but also in drinks, dairy alternatives, and snack products.
That surge in popularity does not surprise Albayram. "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 said.
"But in terms of neuroscience, we still don't know whether the brain has resilience or resistance to this supplement. That's why ours is the first such study in the field."
Albayram collaborated with Eda Karakaya, Ph.D., Adviye Ergul, M.D., Ph.D., and several other researchers at MUSC and partner institutions. Among them was Semir Beyaz, Ph.D., at the Cold Spring Harbor Laboratory Cancer Center in New York.
EPA Identified as a Potential Weak Point in Brain Recovery
The team discovered what they describe as a context-dependent metabolic vulnerability. In simple terms, this means that changes in how cells use energy may reduce the brain's ability to recover under certain conditions. This vulnerability appears to be linked to the buildup of eicosapentaenoic acid, or EPA, one of the main omega-3 fatty acids found in fish oil.
In their experimental models, higher levels of EPA in the brain were associated with weaker repair after injury.
Albayram noted that not all omega-3s behave the same way. Docosahexaenoic acid, or DHA, is well known for its beneficial role in the brain and is a major part of neuronal membranes. EPA, however, follows a different pathway. It is less incorporated into brain structures, and its effects can vary depending on how long it is present and the surrounding biological conditions. Because of this, the long-term impact of omega-3 intake on brain recovery and blood vessel adaptation has remained unclear.
Experiments Link Diet, Brain Biology, and Recovery
To better understand these effects, the researchers used a series of models to connect diet, brain function, and healing. In mice, they examined how long-term fish oil use influenced the brain's response to repeated mild head impacts. Their focus was on signals related to blood vessel stability and repair.
They also studied human brain microvascular endothelial cells, which form part of the barrier between the brain and the bloodstream. In these cells, EPA, but not DHA, was linked to reduced repair capacity, aligning with the findings from the animal models.
To extend the findings to real-world disease, the team analyzed postmortem brain tissue from individuals diagnosed with chronic traumatic encephalopathy (CTE) who had a history of repeated brain injury.
The researchers described the results as having "implications for precision nutrition, therapeutic strategies and the design of dietary interventions targeting brain injury and neurodegeneration."
Key Findings From the Study
The study identified several major patterns, which are summarized below along with simplified explanations.
- EPA-driven neurovascular instability triggers perivascular tauopathy and cognitive decline following TBI.
"In a sensitive brain state modeled in mice, long-term fish oil supplementation revealed a delayed vulnerability. 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