We talk, we joke, we laugh, we read on
topics like, cholesterol, obesity, diabetes, heart attacks, but we don’t
seem to talk or know much about ‘atherosclerosis’ –
may be because it is not a word that could be remembered and pronounced
easily, in particular after that stuff we drink to boost our good cholesterol
(HDL)- the alcoholic beverages!
“hardening of the arteries”) is a disease that starts in
the inner lining (intima) of large blood vessels due to a variety of
insults, and then, as a result fatty/wax-like substance, is deposited.
These appear as fatty streaks in the early stages. They appear even
during the early years of life, even reported in toddlers. Post-mortems
on young American soldiers killed during Vietnamese war, revealed these
fatty streaks, even growing large enough to block the vessels, whilst
the rice eating Vietnamese soldiers showed no such changes. These fatty
streaks get built up from blood cholesterol (LDL), cellular waste products,
white cells, inflammatory cells, and calcium in the blood. They gradually
grow into the lumen, and sometimes through the vessel wall, become firmer,
solid and more stable. These heaps of rubbish build up are called fibrous
plaques, which cause the arteries to narrow preventing the blood from
flowing properly, depriving the tissues with oxygen and nutrients, necessary
for normal functions.
“Atheros” means “gruel”,
porridge”, or “grits”. Think of the appearance of
the outlet pipe in your kitchen sink, the yellowish dirty waxy grits
that accumulates on the inner surface. That would be the same appearance
in the blood vessels affected by athero-sclerosis.
Normally, the inner wall lined by cells
(endothelial cells) is smooth, and non-sticky. It is possible that these
cells are damaged by free radicals, causing oxidative stress, associated
with inflammation. Another reason could be that the inner lining cracks
due to the turbulence of the blood flow, then free radicals cause the
inflammatory reactions. Inflammation is the response to the injury;
there is redness, swelling, heat and dysfunction of the inner lining.
Inflammation is now recognized as an important factor to athero-sclerosis.
Recruitment of white blood cells from the neighbourhood, oxidation of
innocent LDL (bad cholesterol) to become active, eating up of these
oxidized cholesterol by the white cells (macrophages) giving rise to
foam cells, initiate the development of atherosclerotic lesions.
At this stage, I must give some information about ‘oxidation’.
Oxygen is essential for body functions. It is inhaled through the wind-
pipes (trachea, bronchi, bronchioles), into the lungs, from the atmospheric
air. This is carried through the blood stream to the central and peripheral
areas of the body.
This very essential lifesaver, also
acts detrimentally within the body. The molecule of oxygen will give
out an electron from its pair and become free, just like a marriage
breakup and becoming free again. The free electron replaces another
paired electron in a neighboring oxygen molecule making that a free
radical. This chain reaction causes millions of free radicals to be
liberated with in the body. This process is referred to as “oxidation”,
a situation where an oxygen molecule is waiting to be oxidized. Our
survival and gradual dying process is due to oxidation through free
radical intervention, within the body, and from without. One puff of
a cigarette liberates over a million free radicals into the lungs. The
rusting of the metal on your front gate is also due to oxidation. Rancidity
of cooking oils is also due to oxidation.
Atherosclerosis was believed in the past
as a progressive disease characterized by the accumulation of lipids
(fatty material, including bad cholesterol) and fibrous elements in
the larger arteries. This is where it was once believed that eating
too much of cholesterol containing foods, including saturated fat (atherogenic
food), was considered as causing the thickening of the blood vessels.
So, on doctors advise we reduced eating such food, and checked frequently
our blood lipid levels.
Over the past decade, however, we have
come to appreciate a prominent role for inflammation in atherosclerosis
and its complications. So, we believe that bad cholesterol (LDL), though
a main constituent of the atheromatous plaques is only a bystander.
Today we believe that there is a link between artery damage, the inflammatory
process and atherosclerosis of blood vessels.
One of the indications of inflammation
in the arteries is the presence of a substance called “C reactive
protein”(CRP) in the blood, produced by the liver. In heart disease
due to the atheromatous blockage, inflammation, and the presence of
inflammatory cells, marked elevation of CRP level in blood is observed.
So, recent research shows that having a
high C-reactive Protein test means you are at increased risk of suffering
a heart attack or stroke, irrespective of the fact that the cholesterol
level is elevated or not.
C-Reactive Protein levels fluctuate from
day to day, and levels increase with aging, high blood pressure, alcohol
use, smoking, low levels of physical activity, chronic fatigue, coffee
consumption, having elevated triglycerides, insulin resistance and diabetes,
taking oestrogen pill, eating high protein diet and suffering sleep
disturbances, and depression. Gabe Mirkin, M.D. research worker, says,
”At this time the best ways we know to reduce C-reactive protein
levels are exercise and a diet that includes omega-3 fatty acids. Statins
appear to protect against inflammation as well as cholesterol, but they
can cause nerve and muscle damage and deplete the body of co-enzyme
Q10”. (Co-enzyme Q10 is produced in the heart muscle and brain
tissue, and provides energy for their functions)
Now that we know some information about
‘atherosclerosis’, let us discuss the warning signs.
The specific symptoms depend on what arteries
are affected. When arteries to the brain are affected, atherosclerosis
warnings include; Headaches, dizzy spells, ringing of ears, memory problems,
poor concentration and mood changes.
When the arteries to the heart are affected
with atherosclerosis- warning signs are; chest pain and elevated blood
When the arteries of the arms or legs are
affected, the warning signs are; aching muscles fatigue, cramping pains
in the calves, and pain in the hips and thighs. Cramping of the calf
after walking a certain distance is called “intermittent claudicating”.
The radiologists are now able to diagnose the site of atherosclerotic
stenosis (obstruction) by arteriographic dye studies.
High blood pressure damages the inner lining
of blood vessels and lead to atherosclerosis.
Regular blood pressure checks are very important to delay such damage.
Hormone produced by the kidneys named “Angiotensin11
is now one of the usual suspects of atherogenesis. Doctors prescribe
“ACE inhibitors” to prevent damage of vessels.
Smoking too damages the intima. Smoke oxidizes
LDL, and leads to plaque formation.
Diabetes from any cause leads to atherogenesis.
This can be controlled with proper dieting, and medication.
Raising the good cholesterol (HDL) helps
to delay atherogenesis. HDL is composed of A1 and A2. There is talk
of using A1 instead of HDL as your measure of “good” cholesterol.
Feeding mice with lots of A1 get less atherosclerosis; those fed with
lots of A2 paradoxically get more.
There are more factors that lead to atherogenesis,
including elevation of homo-cysteine levels, but the bottom line is,
if you control your weight, exercise, and eat healthy nutritious food,
you have a good chance of delaying this dreaded disease.
One must get laboratory blood tests done
regularly to assess the risk of atherogenesis and heart disease.
Heart attack risk can be assessed by measuring a wide range of markers
including CRP, homocysteine, total cholesterol, HDL and LDL, fibrinogen,
and apolipoproteins B (apo B) and apolipoproteinA-1(apoA-1) levels,
as well as apo ratios.
See your doctor and get these tests done.
There is a simple test one could do to check atherosclerosis- the “palpation
test” on your radial artery.
Place the tips of index and mid fingers
of your right on the front outer side of the left wrist, just above
the crease line. Feel the pulse of the radial artery. When you are sure
that your fingers are on the artery, roll the fingers until the artery
slips under the fingers. If the artery feels firm and resisting, the
vessel is obviously thickened. If the rolling feels soft and elastic,
the artery is not thickened. This test is mainly for the older people.
Daily use of Omega 3 fish oil up to 3000mg will soften blood vessels,
and slow atherogenesis.