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Omega-3s Linked to Mental Illness

Biological Psychiatry

When Grandma told you that fish is brain food, she might have been onto something. In addition to their well-known heart health benefits, the omega-3 fatty acids found in herring, mackerel, salmon, sardines, and other fatty fish have shown benefits for brain health, as well. Research has shown that omega-3s can improve cognitive function in middle-aged adults and may help stave off Alzheimer’s disease and dementia.

Studies have also shown that low blood levels of omega-3s are associated with increased risk of a number of brain disorders, including Attention Deficit Hyperactivity Disorder (ADHD), autism, bipolar disorder, depression, and suicidal ideation. Recently, a team led by scientists from Queen’s University Belfast added to this growing body of research with a study that probed the possible link between blood levels of fatty acids and incidence of psychosis in young adults. The results of their research—the largest study of its kind ever performed—were published in the journal Biological Psychiatry.


The Study

Using data from the University of Bristol’s Children of the 90s study, the Queen’s University team tracked the blood test results of over 3,500 participants for a span of 17 years. The subjects’ fatty acid levels were measured in blood tests collected throughout their lives, at the specific ages of 7, 15, 17, and 24 years old. The researchers focused specifically on blood levels of omega-6 fatty acids, commonly found in vegetable oils used for frying, as well as overall omega-3 levels and levels of docosahexaenoic acid (DHA), a specific type of omega-3. To evaluate their mental state, participants completed a Psychosis-Like Symptoms Interview (PLIKSi) at their age 24 clinical visit.

The researchers’ analysis revealed that participants with persistently higher levels of omega-6 compared to omega-3 fatty acids in their blood, as well as consistently low DHA levels, had more psychotic experiences at age 24 compared to people whose levels remained average over this time period. Psychotic experiences include thoughts of paranoia or hearing sounds others cannot.

In addition, these participants also showed greater negative symptoms of psychosis. Negative symptoms include experiencing a loss of interest in activities, flattening of emotions, and social withdrawal.



While the study was observational, which can’t prove causality, it does add to the growing body of research detailing the importance of both adequate omega-3 intake and—perhaps more importantly—a proper balance of omega-6s to omega-3s for overall health and wellness. This tends to be an issue for many people, especially among those who consume a “Western” diet that includes more fried foods and less fish, and thus a much higher intake of omega-6s than omega-3s.

“This inaugural study is important because the results suggest that optimizing fatty acid status during crucial stages of development, whether through diet or supplementation, warrants further investigation,” said lead author David Mongan, PhD.


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