| |
DHA and Arachidonic acid are the predominant Essential Fatty
Acids in the human brain. Neurons cannot synthesize Arachidonic acid, but
Astrocytes and cerebral Epithelial cells have enzymes that can. The ability
of enzymes to produce the Omega 6 and Omega 3 family of products of Linoleic
and Alpha-Linolenic acid declines with age. One experiment showed that
the Desaturase enzyme function in old rats was only 44% of the Desaturase
function in young rats. This decline in Desaturase activity has provided a
rationale for supplementation with GLA (bypassing the Delta-6-Desaturase
enzyme) and for supplementation with the Omega 3 products EPA and DHA. Fatty
acids in human gray matter, Phosphatidylethanolamine is roughly 25% DHA, 25%
Stearic Acid, 14% Arachidonic and 12% Oleic Acid. In the outer segments of
retina photo-receptors of the eye, DHA accounts for more than 50% of the
fatty acid content, probably because of the high membrane fluidity required
for sensitivity to light.
In the last third of pregnancy and in the first four
months after birth, rapid brain growth in the human infant requires large
amounts of Omega 3 and Omega 6 Essential Fatty Acids. Human milk contains
(in total fatty acids by weight) 12% Linoleic Acid, 0.5% Alpha-Linolenic
Acid, 0.6% Arachidonic Acid and 0.3% DHA. Infant formulas frequently do not
Arachidonic Acid or DHA. One study showed that by (or just before) age 8,
children who had been breast-fed as infants had an 8.3-point IQ advantage
over children who had received formula. The study corrected for the
education and social class of the mother.
|
|
