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Fats and
Oils
Article by herbalist Dave
Hawkins, MH, CNC
First,
lets talk about why it
is important to watch fats in our diet.
The
average American consumes 40% of their caloric intake in
the form of fat.
This is a very
high percentage especially when it has been noted that fat
intake within the 20% range is healthier. Let's look at
this nations number one
disease, heart
disease. It has been clinically proven that fats
in the diet are related to arteriosclerosis and high
cholesterol level and that by reducing
intake of fats, positive results can be seen.
There is a
great deal of research done in this area,
so we will not deal with it in this particular article.
What
is fat?
Fats
and oils are made up of carbon chains but the
fat chain is a simple linear
arrangement of carbon atoms. Fats are a hydrogenated carbon
with hydrogen added. Technically then, fats and
oils are hydrocarbons and are structurally like petroleum.
There are three types of fats:
Saturated, mono-unsaturated and poly-unsaturated. We will
not deal with the technical nature of these types but will
explain them in terms you can understand.
·
Saturated fats are found in animal products
and are solid at room temperature.
Lard is a good example as are dairy products like
cheese and butter.
Beef and pork products are high in saturate
fats and lead to cholesterol problems.
·
Mono-unsaturated fats are liquid at room temperature
and are the best form of oils
to use. Olive and sesame oils are of this type.This
type of fat does not affect blood cholesterol levels.
·
Poly-unsaturated fats are also liquid at room
temperature and are similar to
mono-unsaturated. The main difference is in the
bonding between molecules. Most vegetable oils
are this type (corn, safflower, peanut, etc). They can
help to reduce cholesterol
only if they are
unhydrogenated.
Many people ask
which is better butter or margarine?
Margarine is a hydrogenated, saturated product that was
developed and used widely during World War II because
butter was in short supply. Some margarine is often
advertised as " made from
poly-unsaturated oils " and in fact has small quantities of
liquid poly-unsaturates that
are added to a hydrogenated base. Margarine also is high in
trans fatty acids, which have a
detrimental effect on the body. Butter is saturated but the
molecular chain is different than other saturated fats. It
is semi-soft at room temperature and studies show that some
butter can be beneficial to the body. Of course it depends
on how much a person uses. Remember moderation is the key.
Let's discuss
cholesterol. What is cholesterol?
Cholesterol is a waxy, fat – like substance that is found
in every cell in our bodies. It is the base from which
estrogen, cortisone, cortisol and testosterone are made. It
is a component of nerve tissue. One end of the molecule can
form a salt, which is soluble in water, and the other end
combines well with fat. Cholesterol salts, (bile salts)
promote the mixture of fats in the small intestines with
water so that they can be broken down and absorbed through
the intestinal wall. Cholesterol is not the
villain that we are led to believe.
The
body can synthesize all of the cholesterol that it needs
primarily in the liver. The problem with
cholesterol arises when we get too much in the
blood stream, either produced by the body or
through diet. The average cholesterol count
for Americans is 225-250 mg. per 100 ml. of blood serum.
The cholesterol levels for vegetarians and those on low fat
diets range
from
150-175 mg. per 100 ml. of blood serum.
This is a
significantly lower level and studies show these
people have lower incidence of heart problems.
When cholesterol levels are high the molecules begin to
attach to the arterial walls.
There
are two forms of cholesterol, HDL (High density
Lipo-proteins) and LDL (Low
density Lipo-proteins).
High HDL is said to be beneficial because
the molecular structure is in a loose structure and the
molecules are bigger. They are easier to metabolize. The
LDL is what comes through dietary sources and is a smaller
grouping of molecules, harder to break down.
Since we have
discussed how fats affect our body lets discuss oils and
what's been done to them. There are two methods of
preparing oils. The first is pressure.
The ground or flaked oil bearing material is fed into a
large cylinder and driven against a back plate by a big
screw. The tremendous pressure squeezes out 95% of the oil.
The
second method is the solvent method. The ground
material is bathed in a
solution of hexane or some other petroleum
solvent. The resulting oil solvent solution is then boiled
to drive off the solvent. This is the most popular method
used with commercial oils because only 1-2 % of the oil is
left in residue.
Remember our
" all natural oil?
Natural oils are never prepared in this manner.
Commercial oils go through a few other steps before you buy
it off the grocery shelf. First the oil is washed with a
sodium hydroxide solution to remove the
phosphatides, one being
lecithin. Phosphatides cause
oil to darken in high heat. Next caustic soda combines with
the oil's free fatty acids to form soap stock. Then the oil
is filtered through bentonite,
clay, to bleach it by removing minerals and color
components like chlorophyll and
carotenoids.
The next stage
is to heat the oil by steam to 446 degrees to deodorize it.
The last stage hydrogenation,
an optional stage, in which many of the oil's poly-unsaturates
are saturated with hydrogen to stabilize the oil.
This is done to give oil a longer shelf life.
In many cases, BHT or BHA, anti-oxidants, are added then to
prevent rancidity.
Now that you
know the process that oils go through, what
alternatives do you now have to choose from?
We use oils
that are mechanically pressed which have been through
the least amount of processing. The oils
do have color and flavor but they also have
nutrients that other oils don't have. The
digestibility of pure oils is better and
they don't lead to build up problems in the arteries.
A natural oil has a shelf life
of 4-6 months depending on storage conditions.
We recommend storage either in a refrigerator or in a cool,
dark shelf.
How do
you know if an oil if fresh? Tasting oil and
smelling it are the best ways. If oil is rancid your nose
will tell you immediately. With a little practice you will
be able to tell.
Remember that
fats in the diet need to be reduced and the best way to do
this is to read labels and control the amount used in your
own preparation.
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