What is cholesterol
Cholesterol is a fatty substance known as a lipid which, under normal conditions,
is vital for body functioning in several ways. There are 'good' and 'bad' types of
cholesterol, and triglycerides, a different type of lipid which circulate in the blood
stream. Most of the cholesterol in blood is made in the body from the liver, and the
rest is obtained from certain foods.
Types of Cholesterol and their function
Triglycerides
- A different type of lipid to cholesterol. It is formed
mainly from diet, and is often increased by sugar and
alcohol consumption. The body utilizes triglycerides as
stored energy, which is used when the body is low on
reserves.
Cholesterol is carried throughout the body attached to proteins, hence the
term 'lipoprotein'.
The 'bad' types of cholesterol are LDL and VLDL
- Low density lipoprotein and very low density lipoprotein. LDL is
routinely measured in your cholesterol test, but there is no simple and
direct way to measure VLDL cholesterol. However, VLDL cholesterol is
usually estimated as part of the triglyceride value. This is because
VLDL containes the highest amount of triglyceride.
LDL - Essential for normal cell function and for making hormones such oestrogen
and testosterone. This type of lipoprotein carries cholesterol from the liver to cells of
the body. However, when LDL levels are in excess of need, they circulate in blood
vessels, and adhere to artery walls where they cause disruption and arterial diseases
such as atherosclerosis (narrowing of the arteries), and arteriosclerosis (hardening
of the arteries). LDL build up on the lining of arteries and also cause systemic
inflammation. If LDL is allowed to build up within the artery walls, the flow of
blood to the heart is restricted. This also has a knock of effect of restricting blood to
the brain and the rest of the body. LDL also increases the risk of developing blood
clots. When clots form due to build up of LDL and blood cells on the artery wall, if
it becomes dislodged, it will travel around the body. Blood clots are the cause of a
stroke when a blood clot blocks the artery leading to the brain or a blood vessel within
the brain.
The 'good' type of cholesterol is known as HDL - High density lipoprotein. HDL
carries cholesterol away from the cells and blood stream, returning it to the liver
where it becomes broken down or made into bile (which has a function in digesting
fats). For the above reasons, higher levels of HDL are desired in relation to LDL.
Why it should be controlled
Having excessively high blood lipids (hyperlipidemia) is known to be detrimental to
health. Having high cholesterol levels would not cause any symptoms in itself, but in
time, would increase the risk of cardiovascular disease; coronary artery disease which
greatly increases the risk of a heart attack or stroke and developing angina.
What are considered healthy levels of cholesterol
Usually, when a cholesterol test is undertaken, a total cholesterol result is given to the
patient. However, because of the reasons outlined above, it is important to know
the levels each of LDL cholesterol and HDL cholesterol. The following figures are
at present indicative of desirable and considered harmful levels of total cholesterol in
the U.K., Canada and most of Europe.
(** please note these figures are subject to review and slight change from time to
time).
|
Total Cholesterol Value |
| Desirable |
Below 5.2 mmol/L |
| Borderline high |
5.2 to 6/2 mmol/L |
| High |
Above 5.2 mmol/L |
|
LDL Cholesterol Value |
| Ideal for people who are at
high risk of heart disease |
Below 1.8 mmol/L |
| Ideal for people at risk of
heart disease |
Below 2.6 mmol/L |
| Desirable |
2.6 to 3.3 mmol/L |
| Borderline high |
3.4 to 4.1 mmol/L |
| High |
Above 4.9 mmol/L |
|
HDL Cholesterol Value |
| Poor |
Below 1.0 mmol/L men |
|
Below 1.3 mmol/L women |
| Adequate level |
1.0 to 1.3 mmol/L men |
|
1.3 to 1.5 mmol/L women |
| Very good |
Above 1.5 mmol/L |
|
Total Triglycerides Value |
| Desirable |
Below 1.7 mmol/L |
| Borderline high |
1.7 to 2.2 mmol/L |
| High |
2.3 to 5.6 mmol/L |
| Very high |
Above 5.6 mmol/L |
Who is at risk
Whilst cholesterol can be controlled with lifestyle and dietary changes, there
are certain factors which are beyond control, therefore increasing risk of higher
cholesterol. These are:
-
Genetic factors. If you have a father or brother who developed heart
disease or a stroke before they were 55, or a mother or sister
who developed heart disease or a stroke before they were 65.
Also, close family members who have elevated cholesterol levels
despite a reasonably healthy lifestyle otherwise known as familial
hypercholesterolaemia. ***
-
Being male over 45 years of age.
-
Being female over 55 years of age.
-
An early menopause in women.
-
Increasing age results in increased risk of coronary heart disease,
regardless of cholesterol levels. Unfortunately 'normal' degeneration
of cells and reduction of elasticity over time increase the risk of
developing atheroma. However, it is known that older people are
more prone to higher cholesterol levels than younger people.
-
Ethnic groups. It is known that people who's ethnicity originates in
Asia, India or the Caribbean, and are now 2nd and 3rd generation
immigrants to the U.K. For example, people who live in the UK
have an increased risk of higher cholesterol levels and higher blood
pressure.
*** Despite seemingly to be very difficult to reduce LDL and total cholesterol levels
in familial hypercholesterolaemia without the use of conventional medications, I have
successfully and easily reduced cholesterol by dietary changes. Having elevated
cholesterol is not necessarily linked to a high fat diet, but may be the result of vitamin
and mineral deficiencies, or a deficiency in certain types of fats and oils.
