The primary source of dietary cholesterol is foods of animal
origin, with eggs, red meats, dairy products and prawns very high in
cholesterol.
The main concern is that regardless of the dietary intake of
cholesterol, the human body continues to produce cholesterol every day. The
body is in a position to try to balance the cholesterol it manufactures with
what it takes in by means of food, tending to produce less and to eliminate
more in response to a high cholesterol diet.
In most cases, healthy people are able to maintain a fairly
constant level of cholesterol in the bloodstream, although this level may go up
as a person advances in age. A diet high
in polyunsaturated fats is normally associated with lower levels of blood
cholesterol, whereas a diet high in saturated fats tends to increase the amount
of blood cholesterol.
Saturated fats are the main culprit – they are far more
potent in raising the blood cholesterol level than a diet rich in cholesterol
itself, for instance, eggs. A diet high in saturated fats also causes the body
to retain cholesterol taken in the diet. On a diet low in saturated fats,
dietary cholesterol has little effect.
Cholesterol appears in the fat deposits that form in the
linings of the arteries, causing these arteries to become less elastic. This
process is known as atherosclerosis and takes place gradually in any artery of
the body. When these fatty deposits become heavy and irregular it is known as
plaques. These plaques can restrict or even stop the flow of blood through the
arteries or can cause rough spots that may break loose and form a site for
blood clots. When this occurs in one of the major arteries of the heart, it
causes a coronary.
It must, however, be stressed that diet is not alone in
creating a high risk of heart disease. A person’s heredity, physical activity,
smoking habits, body weight, blood pressure and even a person’s personality may
all play a part.
There are two types of cholesterol-carrying lipoproteins who
may either protect the body against or promote heart disease. Both of these
lipoproteins contain cholesterol but the ‘protective’ higher density ones (HDL)
are found in greater amounts in people who are lean, who exercise, drink
moderately and who do not smoke, while
the ‘promoting’ lower density ones (LDL) are more prevalent in obese people,
sedentary people and people who eat too much fat.
In high risk people the majority of them have blood
cholesterol levels that put them at risk of heart attack. A change towards a
lower-fat, lower-cholesterol diet is a must. Those with additional risk factors
such as a family history of heart disease, overweight, high blood pressure,
smoking or diabetes should cut down on fats and cholesterol even further.
It is a proven fact that lowering blood cholesterol will
lower the risk of coronary heart disease.
Daniel
