DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), omega-3 fatty acids found in fish oil, may help lower triglycerides, reduce the risk of heart disease, improve painful menstrual periods, alleviate depression, lessen asthma severity, and help with ADHD symptoms. Studies have shown that omega-3s affect levels of neurotransmitters like dopamine in the brain. Dopamine influences thinking (cognitive) function and mood, and is the primary neurotransmitter involved in Parkinson’s disease. Omega-3-deficient animals have up to 80% less dopamine release in their brains than control animals.
Researchers from the University of Pittsburgh tested the effects of fish oil supplementation on dopamine transmission and memory in 11 healthy people (average age 22 years). Every day for six months, the participants took 2 grams of fish oil containing 750 mg of DHA and 930 mg of EPA. Before and after the study, the investigators measured blood levels of the fatty acids, did brain scans to determine the amount of dopamine release, and tested memory function in the participants. They found:
“The fact that working memory performance was enhanced by omega-3 supplementation regardless of an effect on [dopamine transmission] suggests that its potential pro-cognitive effects are mediated via extrastriatal dopamine or other non-dopaminergic mechanisms such as effects on inflammation, cellular signaling and trafficking,” commented the researchers. In other words, omega-3’s effects on memory may or may not be related to dopamine in the brain; they could also be from fish oil’s anti-inflammatory actions or from changes in the ways that cells “talk” to each other in the body.
More studies are needed to confirm the results found in this one, and to determine just how fish oil improves memory.
Some plant foods, such as chia seeds or flaxseed, contain omega-3s in the form of alpha-linolenic acid, but the body's capacity to convert alpha-linolenic acid to EPA and DHA is limited. So a fish oil supplement might make a better choice.
(PLOS ONE 7(10):e46832;doi:10.1371/journal.pone.0046832)