LDL and HDL Cholesterol:
What's Bad and What's Good?
Cholesterol can’t
dissolve in the blood. It has to be transported
to and from the cells by carriers called lipoproteins.
Low-density lipoprotein, or LDL, is known as “bad”
cholesterol. High-density lipoprotein, or HDL,
is known as “good” cholesterol. These
two types of lipids, along with triglycerides
and Lp(a) cholesterol, make up your total cholesterol
count, which can be determined through a blood
test.
LDL (Bad) Cholesterol
When too much LDL (bad) cholesterol circulates
in the blood, it can slowly build up in the inner
walls of the arteries that feed the heart and
brain. Together with other substances, it
can form plaque, a thick, hard deposit that can
narrow the arteries and make them less flexible. This
condition is known as atherosclerosis.
If a clot forms and blocks a narrowed artery,
heart attack or stroke can result.
HDL (good) Cholesterol
About one-fourth to one-third of blood cholesterol
is carried by high-density lipoprotein (HDL).
HDL cholesterol is known as “good”
cholesterol, because high levels of HDL seem to
protect against heart attack. Low levels
of HDL (less than 40 mg/dL) also increase the
risk of heart disease. Medical experts think
that HDL tends to carry cholesterol away from
the arteries and back to the liver, where it's
passed from the body. Some experts believe that
HDL removes excess cholesterol from arterial
plaque, slowing its buildup.
Triglycerides
Triglyceride is a form of fat made in
the body. Elevated triglycerides can
be due to overweight/obesity, physical inactivity,
cigarette smoking, excess alcohol consumption
and a diet very high in carbohydrates (60 percent of
total calories or more). People with high triglycerides
often have a high total cholesterol level, including
a high LDL (bad) level and a low HDL (good) level.
Many people with heart disease and/or diabetes
also have high triglyceride levels.
Lp(a) Cholesterol
Lp(a) is a genetic variation of LDL (bad)
cholesterol. A high level of Lp(a) is a significant
risk factor for the premature development of fatty
deposits in arteries. Lp(a) isn’t fully
understood, but it may interact with substances
found in artery walls and contribute to the buildup
of fatty deposits.
|
