Hi, I wanted to continue on with part 2 of our discussion from last week on Cholesterol and how important it is for our health. This may be a little more scientific for some, but hopefully you find this interesting and informative.
Without cholesterol you can not make hormones. Why are we having so many
woman who can’t conceive?
The second function of cholesterol is that mammalian cells do not have solid
cell walls. They are like sacks that are bi-layered. It is like putting two
plastic bags one inside the other and then between the plastic bags,
cholesterol holds them together. Without cholesterol the bags would
disintegrate and fall apart. Cholesterol binds itself between the protein
components and holds the two layers together in such a way that the cell,
acting through hormones on the inside and outside can function. Cholesterol
maintains the structure of the cell wall. We have huge quantities of
cholesterol in our bodies! Cholesterol is vitally important to the
structural protection of the cell. Other life forms have scales and shells.
Plants have cellulose that holds their cells together. We do it with two
protein layers and cholesterol in the middle.
The third function of cholesterol is to act as an antioxidant. You have all
heard about vitamin C and E and other antioxidants. It has only been in the
last ten years that we have realized that cholesterol is equivalent to
vitamin C in an orange. Humans and other animals make cholesterol. The
alcohol portion of the cholesterol molecule is a very powerful free radical
scavenger. If we don’t have enough antioxidant nutrients, guess what gets
pushed in front? Cholesterol-It is used as the antioxidant. This is a very
important concept!
There are receptors on the cells and they are waiting for cholesterol to
come in because they need raw materials to replace the wear and tear that is
going on in the cell membrane. Radiation damage, chemical damage, free
radical damage, emotional damage to our bodies disrupts the cell membrane.
It is the first thing that biologists observe in a stressed system-cellular
membrane breakdown.
The blood lipoprotein that everyone is familiar with is HDL (high density
lipoprotein). About 50% of the molecule is protein, 30% is lecithin and
then a mixture of cholesterol and other fats are found with it. This is a
very small molecule. When HDL comes in contact with the cell, the protein
parts act like a key and they fit on the cell membrane and distribute the
cholesterol. The receptors on the cell membrane recognize it.
HDL is made in the liver. Remember, you do not find cholesterol floating
around. You always find it bound to lipoproteins in the blood and HDL is
the most important.
The second one is called LDL (low density lipoprotein). It has been given a
bad “rap”. LDL is made in the cells of the body throughout the body. It is
larger than HDL. There is both a reduced form and an oxidized form.
Oxidized LDL is cholesterol that is spent. When LDL is oxidized it takes on
a completely different characteristic than when it is not. This is not a
good form.
Then there is VLDL which is a totally insoluble lipoprotein and
Chylomicrons-the largest fats we absorb directly into the bloodstream
(triglyceride-rich particles)
Good versus bad cholesterol is somewhat of a myth. The HDL is called the
good and the rest we tend to call the bad. But it really depends what state
the LDL is in. If it’s oxidized or it’s not, or if we have enough HDL.
LDL is to heart disease just as “skid marks” are to a car accident. LDL is
present in many plaques in the heart. High levels of LDL suggest that the
body is over stimulated and out of control. Just like when you see skid
marks on the road around a curve. You think that person was driving too
fast. If you have LDL going up it may be you are not paying attention to
your body and you are putting more of a chemical load on it and too much
stress. The skid marks do not cause the accidents but they are usually
preceeding them.
What can happen to LDL to make it go from the quality to the oxidized form
which becomes sticky? Oxidative stress!:damage from physical, chemical or
emotional stress (they all produce free radical activity in the body). When
this happens LDL cholesterol combines with the free radicals. If there is
not enough LDL present, the free radicals will increase to the point they
cause tissue damage. The cell membrane gets broken down. LDL is like a
sponge that absorbs free radicals and then becomes oxidized. Think of
oxidation as like metal rusting.
Now you have the basic players who have a role in cholesterol. It is going
to get very interesting from here as you will see. Stay tuned for the next
segment!
Tricia