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Essential Fatty Acids
DESCRIPTION
Essential fatty acids (EFAs) must be obtained through the
diet because the human body cannot make them. The essential
fats are the polyunsaturated fats found in many plants, such
as sunflower, safflower, olives, evening primrose and linseed;
also in fish.
There are different groups
of polyunsaturated fats:-
Omega-3 from fish (and linseed) oils; omega-6 from evening
primrose, (Borage, sunflower, safflower and others), and omega-9
from olive (and linseed).
FUNCTION
Polyunsaturated fats are
important to human health because they are involved in all
cell membrane structures and they also supply the ‘raw
material’ for the production of prostaglandins.
The role of Prostaglandins
Prostaglandins (PGs) derived from both polyunsaturated and
saturated fats have a number of different functions in the
body. Prostaglandins derived from omega-3 fatty acids are
termed PG series 3 whereas those from omega-6 fats are series
E1 prostaglandins (including prostacyclins, formed in arterial
walls and are among the most powerful known inhibitors of
platelet aggregation; they also relax arterial walls and promote
a lowering of blood pressure).
SUPPLEMENTAL USES
Supplementing the diet with
these particular polyunsaturated fats/oils help to balance
the dietary intake of saturated or processed fats found in
meat and dairy products; ready-made pies and pastries; chocolate,
potato crisps and other snack foods.
Essential fatty acids have
a number of important roles in the body including:
The fluidity and flexibility
of cell membranes
Formation of short-lived
hormone like substances called prostaglandins and leukotrienes.
Maintaining the health of the Skin and its permeability to
water.
Cholesterol transport and synthesis.
A similar pathway applies to the saturated fats from most
meat, animal fat, dairy products and coconut. The difference
being that the pathway ends with PG 2 which produce more of
the inflammatory prostaglandins than either of the anti-inflammatory
PGs 1 and 3.
PG series 2 includes thromboxanes
(found in platelets and stimulate them to aggregate which
is important in Wound healing and also to contract the arterial
wall thereby promoting an increase in blood pressure). The
balance between prostacyclin and thromboxane is important
for maintaining normal heart and circulatory function.
However, there are also
some PGs which in excess may be detrimental to health, for
example by contributing to inflammatory responses (e.g. the
leukotrienes which have considerable inflammatory potential).
Blocking Factors of Fatty
Acids into Prostaglandins
Some factors affect the production of the enzyme delta-6-desaturase
which is needed for the efficient conversion of both omega-3
and 6 fatty acids into beneficial prostaglandins, these are:-
viruses
excess cholesterol
saturated fats, trans fatty acids
excess dietary sugar
alcohol
excess alpha linolenic acid (from plant sources of omega-3)
the aging process
low amounts of vitamins B3, B6, C, Biotin
low amounts of minerals Magnesium, Calcium, Selenium and Zinc.
INTERACTIONS
& CONTRA-INDICATIONS
This is dependent on which
EFA is being taken, such as EPO or Fish Oil .
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