By Ralph T. Holman, Hormel Institute, University of Minnesota,
Austin 55912, USA.
Published in the Journal of Nutrition, February 1998;128
(2 Suppl):427S-433S.
Although
linoleic and linolenic acids have been known to be necessary
for normal growth and dermal function since
1930, the omega 3 essential fatty acids (EFA) have not received
much attention until recently. The two families of acids
are metabolized by the same enzymes, making them competitive.
Gross deficiencies of omega 6 plus
omega 3 EFA have been observed in humans, induced by attempts at total parenteral
nutrition (TPN) with preparations devoid of lipids. Deficiency
of omega 3 acids has been induced by TPN containing high
omega 6 and low omega 3 fatty acids.
In natural human populations, a
wide range of omega 3 and omega 6 proportions have been
found, ranging from high omega
3 and low omega 6 content to low omega 3 and high omega 6
content, showing inverse correlation between sigma omega
6 and sigma omega 3. In humans with neuropathy or impairment
of the immune system, significant deficits of omega 3 EFA
have been measured.
