DIET, CHOLESTEROL and HEART DISEASE
Heart disease is one of the world's serious health problems.
Most coronary heart disease is due to blockages in the
arteries that supply blood to the heart muscle. Major
studies have found that reducing cholesterol levels in the
blood and fat in the diet can prevent heart disease and
Cholesterol is a white, fat-like substance. Along with fat it
circulates in the blood and builds up in the walls of the
arteries and can slow or block the flow of blood. This
condition is called atherosclerosis.
Cholesterol is not all bad; it is essential to human life.
Cholesterol provides nerve insulation and helps in the
manufacture of hormones and Vitamin D. Cholesterol is
manufactured naturally by the liver to meet the body's
needs; cholesterol that is consumed in foods is unnecessary
to your body's proper functioning.
To compensate for the extra cholesterol we consume in
foods, the body normally decreases the production of
"natural" cholesterol to maintain a balance. However,
some people, because of diet, metabolism or, family
history, absorb too much cholesterol into their blood and
dispose of the "excess" too slowly.
Excess cholesterol and unsaturated fat collects in the
linings of blood vessels, forming fatty deposits called
plaques. Over time, blood vessels may become clogged,
reducing the blood flow and oxygen supply to the heart
muscle. Without sufficient oxygen to the heart, this may
cause chest pain called "angina", or if the blood supply is
cut off, there is heart muscle injury and a "heart attack,"
possibly resulting in sudden death. Clotting or blockage in
the head or neck can result in a "stroke."
Specific particles carry cholesterol through the blood
stream. These are called "lipoproteins" (a combination of
fat plus protein). Blood cholesterol tests measure the
amount of high-density lipoproteins (HDL -- also known as
"good" cholesterol) and low-density lipoproteins (LDL --
"bad" cholesterol) present in the blood.
HDL (high-density lipoproteins) -- the good guys -- remove
cholesterol from the lining of the arteries and help maintain
good blood flow. LDL (low-density lipoproteins) -- the bad
guys -- deposit cholesterol in the artery wall by forming
plaques. If you have a "high cholesterol" level it usually
means there is an excess of LDL in your blood.
A blood cholesterol level of 240 mg/dL or greater is
considered "high" blood cholesterol. If your blood
cholesterol is 240 mg/dL or greater, you have twice the risk
of heart disease of someone with a level of 200 mg/dL and
you should see your physician for additional testing.
Any total cholesterol level of 200 mg/dL or more, even in
the "borderline-high" category (200-239 mg/dL), increases
your risk for heart disease. Levels less than 200 mg/dL put
you at lower risk for heart disease -- however, this does not
mean "no" risk.
Additional risk factors for heart disease are high blood
pressure and smoking. While each individual risk factor
increases the likelihood of developing heart-related
problems, the more risk factors you have, the greater the
odds of developing heart-related illness. A person with any
two risk factors has four times the risk of someone without
any risk factors. If you smoke, have high blood pressure
and high blood cholesterol, the risk factor can be eight
times as great of developing heart disease than for
someone who has none of the risk factors.
Risk Factors for Coronary Heart Disease
* High blood cholesterol
* Cigarette smoking
* High blood pressure
* Being a male
* Family history of heart disease before the age of 55
* Low HDL-cholesterol (less than 35 mg/dL)
* Circulation disorders of blood vessels to the legs,
arms, and brain
The National Cholesterol Education Program recommends
that all adults age 20 and over have their blood cholesterol
measured at least once every 5 years. If you do not know
your blood cholesterol level, ask your doctor to measure it
at your next visit.
Cholesterol measurement requires a blood sample which
may be drawn from either a vein in your arm or taken by a
fingerprick. If your first measurement is 200 mg/dL or
greater, it should be rechecked with a second measurement
of blood drawn from your arm. You do not have to fast for
this test. If the average of your total cholesterol
measurements is either "borderline-high" or "high" your
doctor will probably ask you to return for another test.
A second measurement is important because it helps your
physician find your "average" level and if a lab error has
been made, will bring this to the attention of your
physician. This test will show value for your LDL and HDL
cholesterol levels and triglycerides. You will have to fast
for 12 hours prior to this test -- you are allowed water or
black coffee during the fast.
Less than 130 mg/dL = Good or desirable level
130 to 159 mg/dL = Borderline-high risk
160 mg/dL or above = High risk
After evaluating your LDL-cholesterol level and other risk
factors your doctor will determine your treatment program.
Your doctor may prescribe a diet low in saturated fat and
cholesterol. However, the higher your LDL-cholesterol level
the more intensive the treatment and follow-up visits
prescribed by your physician. This is because a higher LDL-
cholesterol level increases your risk heart disease.
HDL-cholesterol readings are the reverse of LDL-cholesterol
levels -- the lower the HDL level the greater the risk for
heart disease. Any HDL-cholesterol level lower than 35
mg/dL is considered low. Quitting smoking, losing weight
if you are overweight, and becoming physically active may
help raise your HDL-cholesterol level.
Triglycerides are the form in which fat is carried through
your blood to the tissues. The bulk of your body's fat
tissue is in the form of triglycerides. Triglyceride levels less
than 250 mg/dL are considered normal.
Elevated Cholesterol Levels
Saturated fat raises your blood cholesterol level more than
anything else you eat. Foods high in cholesterol or
saturated fat are: egg yolks, sausage, kidney, liver, and
whole milk products such as butter, cheese, yogurt and ice
cream. Red meats are also higher in cholesterol, but the
leaner the meat, the lower the cholesterol. In addition,
vegetable oils, such as palm, palm kernel, and coconut oil,
contain no cholesterol but are high in saturated fat.
Being overweight may also increase your blood cholesterol
level. Most overweight people with elevated blood
cholesterol levels can help lower their levels by losing
weight. Regular physical activity may help control your
weight and is associated with a reduced risk of heart
disease and lower blood pressure.
Genetic factors affect your blood cholesterol level and can
determine how much you can lower your level by diet.
Age and sex also influence blood cholesterol levels.
Women's blood cholesterol levels prior to menopause are
lower than those of men of the same age. After
menopause, however, the cholesterol level of women
usually increases to a level higher than that of men. In
men, blood cholesterol generally levels off or declines
slightly around age 50. Since the risk of coronary heart
disease is especially high in later decades of life, reducing
high blood cholesterol is important in the elderly.
Oral contraceptives and pregnancy can increase blood
cholesterol levels in some women. For pregnant women,
blood cholesterol levels should return to normal 20 weeks
CVD Case Study | Risk Factor Case Study |Cholesterol Topics
(The above is a summary of information published by: the National Heart, Lung, and Blood Institute, U.S. Department of Health and Human Services; the California Medical Association; and the National Cholesterol Education Program. These materials are meant as a general guideline. You should always consult with your own physician prior to taking action.)