EPA supplements improve cognitive function and reduce brain strain

Omega 3 EPA: a valuable aid for brain health
Supplements rich in Omega 3 EPA (eicosapentaenoic acid), in young subjects, improve cognitive performance and help the brain work with less effort. Those based on DHA (docosahexaenoic acid) seem less effective in enhancing neurocognitive performance.

This is reported by a study published in the journal Human Psychopharmacology: Clinical and Experimental, conducted by researchers from Swinburne University of Technology in Hawthorn (Australia) aiming to study the effects of Omega-3 supplements on brain activity and cognitive abilities.

Omega-3 and cognitive functions
DHA is one of the main constituents of nervous tissue, being one of the major components of neuron membranes. EPA, on the other hand, is found in small amounts in the brain. Both fatty acids are important for the development and function of the central nervous system. Several studies have confirmed that Omega-3 improve cognitive development in children and counteract neurodegenerative processes in the elderly. In particular, they influence memory, spatial-temporal orientation, attention, speech fluency, and cognitive processing speed. 

Visible results with magnetic resonance imaging
The research involved 13 subjects with an average age of 24 years, who were randomly given supplements containing 417 mg of DHA or 590 mg of EPA for 30 days. After a washout period, subjects who had received DHA supplements were given EPA supplements and vice versa for another 30 days. Before and after each treatment, the young participants underwent functional magnetic resonance imaging, a technique that allows visualization of organ function. The researchers obtained a map of brain areas activated during specific cognitive tests designed to assess attention levels and short-term memory.
Results showed that after EPA supplements, activation of the left anterior cingulate cortex, the brain region responsible for cognitive functions such as decision making and impulse control, decreased, while activation of the precentral gyrus, involved in implementing corrective strategies, increased.  Reaction times also decreased noticeably. DHA supplements increased functional activation in the precentral gyrus region but no behavioral changes were observed. The researchers also observed that after both supplements, the ratio between arachidonic acid and EPA was reduced. For scientists, neuronal efficiency reflects the relationship between cognitive performance and brain effort. Humans tend to modify their neuronal activity to maintain an acceptable cognitive performance level.
Thus, measuring performance without considering brain activation levels can yield inaccurate results, as happened in previous studies investigating supplement effects. Analysis showed that EPA and DHA are incorporated differently into cell membranes: EPA is rapidly transformed into phospholipid phosphatidylcholine, positioning on the outer membrane side, while DHA is transformed into phospholipid phosphatidylethanolamine, positioning on the inner side. It is still unclear if changes in cognitive activity relate to the insertion of these molecules into membranes.

EPA supplements are more effective than DHA ones
Extending the neuronal efficiency theory, according to which smarter people activate fewer nerve cells to solve problems, the study demonstrated that thanks to EPA supplements the brain works less and achieves better cognitive performance.  Conversely, increased functional activation and lack of improvement in reaction times and cognitive performance accuracy following DHA supplementation suggest it is less effective. However, as contested by Harry Rice of the Global Organization for EPA and DHA Omega-3, the two supplements were administered at different doses. Researchers noted that in a 2010 study conducted by University of Cincinnati researchers, a similar dose of DHA increased brain activation during a visual attention test. 

Source: Isabelle Bauer, Matthew Hughes, Renee Rowsell, Robyn Cockerell, Andrew Pipingas, Sheila Crewther  and David Crewther. “Omega-3 supplementation improves cognition and modifies brain activation in young adults” Human Psychopharmacology: Clinical and Experimental. Vol. 29, Issue 2, pages 133–144, March 2014