Of the two fish-borne omega-3s, DHA is the one considered essential for child brain and vision development, and to eye and brain function throughout life.
In fact, 60 percent of the fat in the human brain is DHA, which is found in and critical to the function of brain cell (neuron) membranes.
Let's take a closer look at the study and what it might mean.
Cincinnati MRI study links omega-3 DHA to brain activation in boys
While a growing body of evidence links DHA to optimal brain function, it hasn't been clear whether or how dietary DHA affects activity in the cortex or “grey matter” of the human brain.
(The cerebral cortex plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness.)
To bridge this knowledge gap, scientists from the University of Cincinnati recruited 33 health boys aged between eight and 10 for a clinical trial in which they used functional MRI (fMRI) scans to view changes in brain activity.
Functional MRI (fMRI) scans show changes in blood flow in the brain, which occur when brain cells (neurons) become more or less active. Thanks to its safety and its unique capacity to reveal these dynamic changes, fMRI imaging now dominates the science of brain mapping.
The boys were randomly assigned to receive either of two doses of DHA (400 or 1200 mg per day), or placebo capsules, for eight weeks.
The Cincinnati group then scanned the boys' brains as they played video games… a task that requires decisions, memory, and sustained attention.
The main finding was that boys in the DHA groups showed significant activity increases in the part of the brain associated with working memory (dorsolateral prefrontal cortex).
Working memory is required for the integration, processing, disposal, and retrieval of information.
The fMRI scans also revealed increased activity in the brain's vision processing and motor control centers (occipital and cerebellar cortex)
As expected, the boys who got DHA showed increased levels in the membranes of red blood cells (erythrocytes).
DHA levels increased by 47 and 70 percent in the low and high dose DHA groups respectively, while the placebo groups experienced an 11 percent drop in DHA levels.
The Cincinnati team noted that fMRI imaging could help reveal the mechanisms underlying psychiatric disorders associated with DHA deficiencies, including ADHD and major depression.
We can't draw any firm conclusions about the meaning of these fMRI findings with regard to learning and other mental tasks... but they seem to support the positive outcomes of some studies on the developmental benefits of dietary omega-3s.
The study was co-funded by DHA supplement maker Martek, the National Institutes of Health, and the Inflammation Research Foundation.
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