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Cholesterol – the bad fellow (LDL), and saturated fats, have been
blamed since the nineteen fifties, when saturated fats were found to cause
a new disease called ‘heart disease’. Ancel Keys an American
researcher, in 1953 observed that those saturated fats in the diet might
play a part, as a cause of coronary heart disease. Using data from seven
countries, Keys compared the death rates from coronary heart disease and
the amount of fats eaten in those countries to demonstrate that heart
disease mortality was higher in the countries that consumed more fat than
it was in those countries that consumed less.
It seems, data from
many other countries were available, but Keys ignored the data from those
that did not support his hypothesis. So the diet/heart hypothesis was
born.
The fear for cholesterol
was so conspicuous, even manufacturers of foods started labeling them
“cholesterol free”, to market their products. Using animal
fats, including butter, were shunned by the housewives; vegetable oils
and margarine became the popular substitutes
People started going
for health check ups annually to test their cholesterol levels in the
blood. What is so ironical about the check ups is that most people did
have the tests, but took no precautionary steps to remedy, if and when
the cholesterol level was high. So with the annual health check ups, mostly
paid by the companies, the tests became very popular, but the cholesterol
levels among them remained high as ever. In short lifestyles did not change,
but the motivation was just to go for the check ups.
Does cholesterol cause
coronary heart disease? It is a minor risk indicator, says Dr Eduardo
Castro,(Medical Director, Mount Rogers Clinic, VA), that has been distorted
out of proportion, largely, because the cholesterol lowering drugs help
decrease the incidence of adverse cardiovascular events.
The assumption is
that if cholesterol-lowering drugs lead to clinical improvement, then
cholesterol must be the culprit. There is increasing evidence that these
‘statin drugs’ more than helping to reduce cholesterol levels,
they do act by decreasing the inflammatory processes in the inner lining
of the arteries. The inflammation is preceded by cracks in the inner lining,
due to turbulence of the blood flow, in addition to various other causes.
Cholesterol is a yellowish
waxy water insoluble material floating in the blood stream. Being oily
and water insoluble, it attaches itself to lipo-proteins making it water-soluble.
Hence, the bad cholesterol is labeled as low-density lipo-protein (LDL),
and the good cholesterol attached to high-density lipoproteins is called
HDL.
Cholesterol is a sort
of a cousin of fat. Both fat and cholesterol belong to a larger family
of chemical compounds called lipids.
Cracks in the walls
of the blood vessels, with surrounding inflammation attracts the floating
blood cholesterol, transports to these sites, as cholesterol is needed
for healing. Think of the cracks on your walls. The mason seals them with
white cement. Waxy, pasty, cholesterol does exactly the same on the cracked
inner lining of blood vessels. The next stage would be, the cholesterol
collects at these sites in heaps, mixed with calcium, inflammatory cells,
and scavenging cells from the neighbourhood. These heaped up areas are
referred to as athero-matous plaques.( ‘Atheros’ means “gruel”
or “porridge”).
So it appears that
cholesterol is only an innocent bystander. Cholesterol is not a waste
product. Over 90 percent of cholesterol is made in the liver and intestines
from fatty acids and ethanol (alcohol). Cells throughout the body use
cholesterol to make a number of hormones necessary for growth and reproduction.
Cholesterol is a precursor molecule for oestrogen, progesterone, and testosterone.
The adrenal hormones that combat stress and relieve inflammation are cholesterol
dependent. When there is damage to the walls of the arteries or veins,
the liver sends cholesterol through the blood to protect the tissue from
hemorrhaging. Cholesterol is a component of all cell walls. They are vital
to proper brain and nerve function. Low levels of cholesterol have been
associated with depression, anxiety, and mood disorder. Mother’s
milk is saturated with cholesterol, as it is nature’s most important
component for defense and building material of the tissues of the baby.
The body has a regulatory
mechanism for cholesterol, as for other endocrine systems. If one eats
excess cholesterol from animal foods, eggs yolk, cheese, shellfish, and
whole dairy products, the liver would produce less cholesterol from fats,
and vice versa. Also, it is observed that dietetic cholesterol has no
effect on the serum cholesterol.
The most influential
and respected investigations of the causes of heart disease, is the Framingham
Heart Study. Doctors from Harvard Medical School set up this study in
the town of Framingham, Massachusetts. They measured cholesterol intake
from diet and compared it with blood cholesterol. Though, subjects consumed
cholesterol over a wide range, there was little or no difference in the
levels of cholesterol in their blood, and thus, no relationship between
the amount of cholesterol eaten and levels of blood cholesterol, was found.
It was also noted that women who had the highest levels of cholesterol
in their blood were ones who had eaten the least cholesterol.
After 22 years of
research, the researchers concluded, “There is, in short, no suggestion
of any relation between diet and the subsequent development of coronary
heart disease in the study group.
The amount of cholesterol
produced in the liver is about two grams a day, and the average amount
eaten is about 300mg. An egg contains about 190-200mgs of cholesterol.
So, without fear, one could have an egg everyday, contrary to previous
beliefs.
Serum or blood cholesterol
is manufactured in the liver, and intestines. Labeling as good or bad
cholesterol depends onto which (low density or high density) lipoprotein
the cholesterol gets attached to.
In real terms, the
liver does not over-produce cholesterol. The excess, if any would be excreted
as bile salts, which in turn facilitates further fat digestion and absorption
of fatty acids, and cholesterol. The latter, are carried to the liver
in combination with lipoproteins, as chylomicrons.
Talking about lipoproteins,
or to be exact apolipoproteins, are particles of protein that are mostly
formed in the liver and intestine. They play an important role in the
production and transport of cholesterol around the body. There are at
least nine types of apolipoprotein, including apo A-1, apo B and apo E.
Each type bonds with cholesterol in the blood- either as the protective
cholesterol, known as High Density Lipoproteins (HDL), or the more harmful
cholesterol, Low Density Lipoproteins (LDL).
It is now observed,
especially in countries like Sri Lanka, high cholesterol levels are due
more to the carbohydrates we eat than fats. Carbohydrates, like rice,
bread and other products from wheat flour, are broken down to sugar, glucose.
Insulin is secreted to lower elevated glucose levels in the blood. Insulin
is a major factor in determining how much cholesterol and triglycerides
our livers produce.
If you wish to lower
the cholesterol level, then limit sugar intake, as well as the carbohydrates
that rapidly cause elevated blood sugar levels. Knowing the “glycaemic
Index” of the carbohydrates you eat would help you to control your
sugar intake.
It is well noted that
we do not eat much fat per day, but it is the bulk formed by carbohydrates
that are responsible for heart disease, obesity, high blood pressure,
diabetes, and even arthritis.
There is more evidence
that cholesterol is not the culprit. One that supports the ‘healthy’
recommendations was a Finnish trial published in 1975. In the five years
trial run, cholesterol levels were lowered significantly, and the study
was hailed as a success. But in December 1991 the results of a ten year
follow-up to that trial found that those people who continued to follow
the carefully controlled, cholesterol lowering diet were twice as likely
to die of heart disease as those who didn’t- some success!
Prof Michael Oliver
writing in the British Medical Journal, commenting on the results writes-
“As multiple intervention against risk factors for coronary heart
disease in middle aged men at only moderate risk seems to have failed
to reduce both morbidity and mortality such interventions become increasingly
difficult to justify. This runs counter to the recommendations of many
national and international advisory bodies, which must now take the recent
findings from Finland with consideration. Not to do so may be ethically
unacceptable”.
Let’s take
Japan as an example. Japanese intake of animal fat has more than doubled
since the end of the Second World War. Over the same period the incidence
of coronary heart disease has fallen consistently.
In Israel, too an
increased consumption of saturated fats was followed by a fall in coronary
deaths.
Among south Asians
in Britain there is an unusually high incidence of heart disease, yet
living on vegetarian diets, they have low levels of blood cholesterol
and eat diets that are low in saturated fats.
Until recently, Indians
in India had a very low incidence of heart disease while using ghee, coconut
oil, and mustard seed oil- all of which are highly saturated. The epidemic
of heart disease in India began only after these were replaced with peanut,
safflower, sunflower, sesame and soy bean oils, all of which are high
in hydrogenated polyunsaturated oils, made into trans-fats to preserve
the shelf life.
It is seen clearly,
with so much trials going on in many countries, there are many doubts
that cholesterol is the culprit that is related to heart disease. Atherosclerosis
is definitely a specific causative factor related to heart disease. One
must find the causes that lead to this thickening and blocking of vessels,
rather than blaming cholesterol, including saturated fats as sure-fire
sign of a future heart attack.
Cigarette smoking, High blood pressure, diabetes from any cause, lack
of exercise, biochemical lesions, those that promote thrombosis, lack
of certain lipoproteins, elevated levels of homo-cysteine, and many other
unknown factors may be responsible for atherosclerosis –precursor
of heart disease.
When studies failed
to prove that lowering cholesterol made any lifesaving differences, researchers
forged ahead with more multi-million dollar clinical trials. Not until
statin drugs (Lipitor,Zocor,Pravachol), came along did cholesterol-lowering
finally prove to be life-saving to high-risk but healthy people. Whether
this benefit might actually be due to the anti-inflammatory effects of
statins has been the topic of controversy ever since.
Dr Ravnskov, another
researcher, is very unimpressed with the reduction in heart disease mortality
shown
for the statin drugs “When you look at the CARE trial, he said,
statin drug Pravachol did show a small benefit- after five years. 5.7%
had died from heart disease in the untreated control group, compared to
only 4.6% in the treatment group”. This researcher also believes
that high cholesterol protects against cancer. It was his observation
that his studies found higher rates of infectious disease among hospitalized
people with low cholesterols. Also several studies found higher cancer
rates in people with low cholesterol levels.
It was found women who took Pravachol in the CARE trial, 12 cases had
breast cancer, compared with only one case in the untreated group.
Dr Paul Rosch, MD,
a clinical professor of medicine at New York Medical College, is of opinion
that half of all heart attacks occur in people with normal cholesterol
levels. He further believes that stress has more deleterious effects on
the heart than cholesterol.
There has been cases reported transient memory loss after statins. Duane
Graveline, MD, a retired family doctor and former NASA scientist/astronaut,
recounted his own hair-raising experience taking the popular statin drug
Lipitor for only six weeks. Soon after he went for a walk, Dr Graveline
was found wandering, confused, and reluctant to enter his own home because
he didn’t recognize it or remember his wife’s name. A neurologist
diagnosed his condition as ‘Transient global amnesia’.
The other side effects
of statin drugs are muscle pain, weakness, fatigue, peripheral neuropathy,
and rhabdomyolysis, a potential fatal muscle disease.
It is observed by
many researchers that statin drug’s ability to reduce cardiovascular
mortality has nothing to do with cholesterol reduction, but instead can
be attributed to their anti-inflammatory effects. These drugs also deplete
the body of an important anti-oxidant with muscle wasting and heart failure
as a result. Co-enzyme Q10 is an important anti-oxidant formed as a bi-product
in the manufacture of cholesterol. With taking statin drugs will inhibit
the production of coenzyme Q10, by the liver.
Dr Peter Langsjoen MD of Tyler, Texas points out that this co-enzyme is
present in traditional foods with high fat content like organ meat, seafood,
and red meat. The coenzyme Q10 drops with age. Most of the Q10 research
has been focused on heart failure, as the heart uses a huge amount of
Q10. Q10 is available in powder form, and can be purchased from health
food shops, and supplementation is advisable for those who take large
strengths of statin drugs, regularly.
Lastly, one more comment-
a study of elderly French women living in a nursing home showed that those
with the highest cholesterol levels lived the longest (Lancet, 4/22/89).
The death rate was more than five times higher for women with very low
cholesterol. Several other studies have shown similar results.
The author has had many very healthy old ladies over 90 years, in his
practice in Sydney, still worried about their high cholesterol levels.
There you are, what more can I say! |