What they are:
As the name implies, the fatty
acids are a group of fatty molecules that
are essential
to life. They are the building
blocks of fats, one of the 3 main components
of nutrition; the others being
carbohydrates and proteins.
The fatty acids are acids in
the sense that their chemical structure contains
an acidic
component.
Structure
Fatty acids are composed of a
backbone of
carbon atoms linked in chains.
The chain linkages can be either
single bonds
or double bonds and their names
reflect where
in the chain the double bonds
occur.
For example:
Omega-6 fatty acids are so named
because
they have double bonds ending
at position
6 of the molecule.
Omega-3 fatty acids have double
bonds ending
at position 3 of the molecule.
How they are classified:
Fatty acids are classified as
eithersaturated (which mean they contain only single bonds
in their structure) or unsaturated(containing double bonds).
The Unsaturated fatty acids can be either mono-unsaturated (this means they contain only 1 double-bond
) or poly-unsaturated (containing multiple double bonds).
Saturated fatty acids
This is the most common form
found in the
diet.
These saturated fatty acids are
12, 14, and
16-carbon lengths, respectively.
Unsaturated fatty acids
As you have seen in the introduction, the
unsaturated fatty acids can take
the mono- or poly-unsaturated forms.
Mono-unsaturated fatty acids:
- Palmitoleic,
- gadoleic
- cetoleic
Poly-unsaturated fatty acids:
- Linoleic (w-6 fatty acid, 18 carbon-length,
2 double-bonds 6-carbons from the methyl
end)
- Alpha-linolenic (w-3 fatty acid, 18 carbon
length, 3 double bonds, 3 -carbons from the
methyl end)
- Gamma-linolenic acid (differs from alpha-form
by containing 6 double bonds)
- Arachidonic acid ( 20 carbon length, 4 double-bonds)
- Eicosapentaenoic acid (20 carbon length,
5 double bonds)
Linoleic and alpha-linolenic acid must be
obtained from the diet as the body cannot assimilate them. They are the essential fatty acids.
Dietary Sources
Main dietary sources of Mono-unsaturated
fatty acids:
Main dietary sources of Poly-unsaturated
fatty acids:
- for omega-6 fatty acids: vegetable oils, eg. sunflower and corn
oil; kidney beans, soybeans. Evening primrose
oil is particularly rich in linoleic acid
and eicopentaenoic acid; fish such as salmon,
mackerel, tuna, herring.
- for omega-3 fatty acids: fish, such as salmon, mackerel, tuna, herring;
flaxseed oil.
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Fatty Acid Guide
