Essential
fatty acids
Essential
fatty acids or "essential fats" are a kind of
poly-unsaturated fatty acids that are dietary essentials in humans
required for normal growth in infants and young children. They are also
required in adults for normal body homeostasis.
But;
before
understanding essential fats, please read about FATS;
Dietary fats are composed primarily of fatty acids and
cholesterol. Fatty acids are classified primarily
based upon their chemical structure as;
- Saturated: - SFA (because they have no double
bonds in their chain). Examples with more percentage of saturated fats
include butter,
coconut oil, palm kernel oil, lard-butter etc.
- Mono unsaturated: - MUFA (with one double bond
in their chain). Examples of oils with more percentage of
monounsaturated fats are
olive oil, mustard oil etc.
- Poly unsaturated: - PUFA (have more than one
double bond in their chain). Examples of oils with more
percentage of poly-unsaturated fats are sunflower oil, safflower oil
etc.
- Trans
fats: - Trans fatty acids
(trans fats) are a particular form of unsaturated fats formed during
cooking of vegetable oils due to partial hydrogenation, but behave like
saturated fats in the body by increasing levels of LDL or bad
cholesterol.
And
now...What are essential fatty acids?
Why are they so “essential”?
As mentioned above, essential fatty acids are a kind of
poly-unsaturated fatty acids that must be present in the food we eat
for normal growth and development in infants, young children and
adults.
The two most important essential fatty acids are;
- Linoleic
acid: The principle precursor of
omega-6 fatty acids that play role in pro-inflammatory reactions, such
as formation thrombus (blood clots), allergic reactions.
- Linolenic
acid: The precursor of omega-3 fatty
acids that is important for growth and development.
Although omega-6 fats are
pro-inflammatory, still they are required for
normal body functions such as maintaining integrity of cell membranes,
healthy skin, kidney function, and to combat against bacteria
and viruses. In fact, both omega-6 and omega-3 must be present in the
diet for normal body homeostasis. However, the diet must contain
desired
omega-6 to omega-3 ratio of 5:1 to 10:1. This is because, high omega-6
and
low omega-3 content as in sesame(43:0), safflower(77:0), sunflower
oils(69:1) can predispose to free
radical mediated cell injury, impaired immune function, reduced
glucose tolerance and diabetes,
increased blood clot formations resulting in coronary heart disease and
stroke episodes.
So...what cooking oils have favorable omega-6: omega-3 ratio?
Soybean oil (8:1);
olive oil (8:1).
For example,
the complete fat profile of Olive
oilis
here;
| Item |
SFA% |
MUFA% |
PUFA%
ω-6 ω-3
|
ω-6
to
ω-3 ratio |
Remarks |
| Olive
oil |
14% |
77% |
8%
1% |
8:1 |
Very
good |
Omega-3 fatty acids
Omega-3
fatty acids like α-linolenic acid, decosahexaenoic acid (DHA)
and eicosapentaenoic caid (EPA) should be present in the diet in the
range of 0.6 to 1.2 percent of total calories intake. All the omega-3's
present in the nature are essentially derived from the plant kingdom
such as green algae, blue-green algae, plankton etc. Amphibians like
fish are rich in them when they feed on algae and accumulate in great
levels.
Excessive consumption of fish for omega-3's may result in heavy metal
poisong like mercury, arsenic, cadmium, lead etc. There are many plant
sources such as flax sees, hemp, pumpkin seeds, kiwi fruit, nuts like
almond, walnuts are rich in omega-3's as alternative to fish.
Health
benefits of essential fatty acids
- Both
leinoleic (omega-6) and linolenic acids
(omega-3) are building blocks of brain lipids. Therefore,
they are absolutely essential for normal fetal and infant brain as well
as body growth, and development of visual acuity.
- These fats
along with other fat
soluble vitamins like vitamin-A are required by the body for
maintenance of healthy skin and mucus membranes.
- Fats with
good omega-6 to omega-3 profile has
been proved to reduce LDL OR bad cholesterol and rise HDL or good
cholesterol levels; thus, helps to prevent coronary heart disease (CHD)
and stroke episodes.
- Omega-3
fats reduce pro-inflammatory
prostoglandins and leukotrienes in the body. Deficieny may result in
co-morbid conditions like dyslexia (difficulty reading), dysgraphia
(difficulty in writing) and attenton deficit-hyperactivity disease in
children.
Sources
of essential fats
Vegetable
oils are good sources of essential fats; however, the desired
ratio of omega-6 to omega-3 that should be present in them is between
5:1 to 10:1.
The foods rich in essential
fats are:
<<-Recommended Dietary
fats and oils... Read on...
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Further
Reading: Refer Stanford School of Medicine Cancer
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Nutrition to Reduce
Cancer Risk
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