Omega-3 Boosts Brain Function
Supplements of the omega-3 fatty acid DHA (docosahexaenoic acid)
may alter the function of the brain associated with working memory,
according to results of a new study with healthy boys.
Scientists from the University of Cincinnati showed for the first
time using neuro-imaging that supplementation with DHA alters
the functional activity in cortical attention networks in humans.
The present findings add to an emerging body of evidence
from preclinical and clinical imaging studies that suggest that
dietary DHA intake is a robust modulator of functional cortical
activity, wrote lead author Robert McNamara in the American
Journal of Clinical Nutrition.
The study follows hot on the heels of, and vindicates, backing
from the European Food Safety Authority (EFSA) for DHA-related
brain and eye health claims for infants.
EFSAs Panel on Dietetic Products, Nutrition and Allergies
(NDA) said DHA (docosahexaenoic acid) levels of 100mg of per day
were appropriate for 7-24 month-old infants along with 200mg per
day for pregnant and lactating women.
The DHA claims relating to brain health stated: DHA intake
can contribute to normal brain development of the foetus, infant
and young children
Another shorter chain, omega-3 fatty acid, ALA (alpha linolenic
acid), was affirmed as important for the normal brain development
of children up to the age of 18 but no levels were specified.
While there is a growing body of evidence linking DHA to cognitive
function, Dr McNamara and his co-workers note that it is unkown
how DHA supplementation may affect functional cortical activity
in humans. In order to fill this knowledge gap, they recruited
33 health boys aged between 8 and 10 and randomly assigned them
to receive one of two doses of DHA (400 or 1200 mg per day, Martek
Biosciences) or placebo for eight weeks.
Brain activation patterns were measured using functional magnetic
resonance imaging (fMRI) during a test of sustained attention
(playing video games). The results showed that DHA levels in the
membrane of red blood cells (erythrocytes ) increased by 47 and
70 per cent in the low and high dose DHA group, while the placebo
groups experienced an 11 per cent drop in DHA levels.
The main finding from the fMRI data was an indication
of significant increases in the activation of the dorsolateral
prefrontal cortex part of the brain in the DHA groups an
area of the brain associated with working memory. Changes in other
parts of the brain, including the occipital cortex (the visual
processing centre) and the cerebellar cortex (plays a role in
motor control) were observed.
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 researchers.
The study was co-funded by Martek, the National Institutes of
Health, and the Inflammation Research Foundation.
Source: American Journal of Clinical Nutrition
February 25, 2010