Growing research suggests that DHA (docosahexaenoic acid), the principal omega-3 fatty acid in brain gray matter, positively regulates brain metabolic function and cognitive development.
In a new study in healthy young boys, scientists from the University of Cincinnati showed that supplementation with DHA raises the body’s DHA levels significantly and positively increases the functional activity of the brain associated with attention and memory.
The study results showed that DHA levels in the membrane of red blood cells (erythrocytes ) increased by 47% in the group supplemented with 400mg/day and 70% percent in the 1200/day group over a period of 8 weeks, while the placebo groups experienced an 11% drop in DHA levels.
Brain activation patterns were measured using functional Magnetic Resonance Imaging (fMRI) during a test of sustained attention (playing video games).
The “main finding” of the study showed that supplementation with DHA significantly increases in the activation of the prefrontal cortex part of the brain – an area of the brain associated with attention, rational thinking and working memory.
A decrease of activity in other parts of the brain, including the occipital cortex (the visual processing centre) and the cerebellar cortex (which plays a role in motor control) were observed during DHA supplementation.
The higher dose DHA resulted in a greater decrease in activation of the cerebellum.
“These findings suggest that this imaging paradigm could be useful for elucidating neurobiological mechanisms underlying deficits in cortical activity in psychiatric disorders associated with DHA deficiencies, including ADHD and major depression,” wrote the authors of the research study.
More studies may be needed to determine the best dose to insure optimal activation of attention and memory without overly suppressing the activity of the visual and motor functions of the brain.
Dr. Hansen recommends a maximum DHA dose of 400mg/day to enhance attention, rational thinking and memory without overly suppressing visual and motor functions of the brain.
Source:
American Journal of Clinical Nutrition
Am J Clin Nutr. 2010 Feb 3. [Epub ahead of print]
“Docosahexaenoic acid supplementation increases prefrontal cortex activation during sustained attention in healthy boys: a placebo-controlled, dose-ranging, functional magnetic resonance imaging study”
Authors: R.K. McNamara, J. Able, R. Jandacek, T. Rider, et al.