Cholesterol: Know The Facts
Cholesterol: Know the Facts
To Your Health
April, 2007 (Vol. 01, Issue 04)
Cholesterol: Know the Facts
By Peter W. Crownfield
It's in the news on a near-weekly basis. Research studies address various
aspects of it. National organizations and expert panels issue
recommendations on it. "It" is CHOLESTEROL. Here are the answers to
frequently asked questions about this strange substance that can have a
profound effect on your health.
Do you know the causes of high cholesterol and the steps you can take to
reduce your risk of serious disease? Do you know the different types, and
how each type can affect your health? What you know is vital to your
longevity: According to the American Heart Association (AHA), an estimated
70 million Americans suffer from one or more forms of cardiovascular
disease (CVD). These diseases claimed 927,448 lives in the U.S. in 2002 -
more than the total lives claimed by cancer, accidents and HIV combined.
And in case you view CVD as a condition exclusive to the elderly
population, take note that more than 150,000 of those killed by CVD in
2002 were under the age of 65.
The major type of cardiovascular disease, coronary heart disease (CHD), is
caused by arteriosclerosis: the thickening or hardening of the coronary
arteries. Here's where cholesterol enters the picture. Findings from the
massive Framingham Heart Study, which began in 1948 under the direction of
the National Heart Institute (now known as the National Heart, Lung and
Blood Institute), show that blood cholesterol is a risk factor for
coronary heart disease, and that the higher the cholesterol level, the
greater the CHD risk.
THE BASICS Cholesterol is a soft, wax-like lipid that occurs naturally in
the bloodstream and in cell walls and membranes. It is a normal and
important part of a healthy body because of the essential role it plays in
cell membrane, hormone, and vitamin D production, as well as the digestive
The liver produces approximately 1,000 milligrams (mg) of cholesterol
daily from other fats, which is all the cholesterol the body needs. In
other words, you don't need to consume cholesterol from dietary sources to
stay healthy. (Infants are the exception: During the growth process, their
bodies make new cell membranes so rapidly that they require a certain
amount of dietary cholesterol.)
Because the body doesn't need dietary cholesterol, particularly not
cholesterol with "no place to go," it means that consumption of
cholesterol-laden foods can cause plaque formation/buildup and resulting
LDL, HDL AND TRIGLYCERIDES First, a little technical background: Dietary
fat is absorbed by the intestine and transported to the liver. The liver
then converts fat into cholesterol and releases it into the bloodstream.
Because cholesterol isn't water-soluble, cholesterol and triglycerides (a
blood lipid) combine with proteins to form lipoproteins, which then
transport cholesterol through the watery blood system.
Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) are the
two main types of lipoproteins; they differ markedly from one another in
their ratio of cholesterol and triglycerides to protein, and thus, in
their effect on blood levels of cholesterol.
LDL: the "bad" cholesterol. LDLs carry a great deal of cholesterol,
because they help transport it from the liver to the rest of the body. Too
much LDL cholesterol circulating in the blood can cause buildup on the
inner walls of the arteries that feed the heart and brain. Over time, LDL
cholesterol can contribute to the formation of plaque - a thick, hard
deposit that clogs arteries, resulting in atherosclerosis. As arteries
narrow, the oxygen supply to the heart is gradually compromised, and the
risk for a heart attack grows.
HDL: the "good" cholesterol. HDLs carry relatively little cholesterol -
they actually circulate in the bloodstream, helping remove excess
cholesterol from blood and tissues. Specifically, evidence suggests that
HDLs tend to carry cholesterol away from the arteries and back to the
liver, where it is then eliminated from the body; and that HDLs also
remove excess cholesterol from plaque in the arteries, resulting in a
slower potential buildup of plaque.
TRIGLYCERIDES transport and store fat in the body. It's clear that high
triglyceride levels aren't good for the body and can be particularly
problematic when combined with excess levels of LDL cholesterol. People
with high triglycerides often have high total cholesterol, high LDL
cholesterol, and low HDL cholesterol. And some lipoproteins are rich in
triglycerides that also contain cholesterol.
The National Cholesterol Education Program, developed by the National
Heart, Lung and Blood Institute of the National Institutes of Health, has
set the "safe" total cholesterol level at 200 mg/dL. A score of 200 or
higher signifies increased risk for developing heart disease; over 240
puts you in the high-risk category.
An LDL cholesterol level of less than 130 mg/dL is acceptable for most
people; less than 100 mg/dL is ideal. The desirable level of LDL
cholesterol depends on whether an individual has risk factors for coronary
artery disease, or a pre-existing health condition caused by
atherosclerosis or diabetes.
The AHA and the American Diabetes Association currently recommend HDL
levels of at least 40 mg/dL for men and at least 50 mg/dL for women. A
blood level of 60 mg/dL or above is ideal.
The HDL:LDL ratio is crucial - perhaps more so than the total cholesterol
score. For example, if you have a total cholesterol score of less than 200
mg/dL, you could still be at risk for developing cholesterol-related
atherosclerosis - if your LDL level constitutes a large percentage of that
score. By comparison, if your total cholesterol is higher than 200 mg/dL,
you may actually be at less risk, if your HDL score is high.
THE FOOD FACTOR: SATURATED VS. UNSATURATED Way back in 1984, the Coronary
Primary Prevention Trial provided some of the first evidence that reducing
total and LDL cholesterol levels significantly reduces the incidence of
CHD; more recent investigations have affirmed this association. Dietary
habits play a major role in determining your total blood cholesterol
level, as well as the relative distribution of HDL and LDL cholesterol.
Consumption of foods high in saturated fat and LDL cholesterol are a major
reason for out-of-control cholesterol levels and rising heart attack rates
in the United States.
All foods that contain fat have different distributions of saturated and
unsaturated fats. Saturated fat is found primarily in foods that come from
animals - red meat (particularly fatty cuts), poultry with the skin on,
whole-milk dairy products (whole milk, butter, cheese, ice cream), and
tropical oils (coconut, palm kernel, etc.). Consumption of saturated fat
increases LDL and total cholesterol in the bloodstream.
On the other hand, unsaturated fats do just the opposite: They increase
HDL cholesterol and reduce LDL cholesterol and triglycerides. Good sources
of monounsaturated fat are canola, peanut and olive oil; olives; avocados;
and most nuts. Polyunsaturated fat can be found in corn, soybean,
safflower, and cottonseed oils, as well as in fish. And let's not forget
omega-3 fatty acids, a type of polyunsaturated fat. Evidence suggests
omega-3s, good sources of which are fatty fish, such as mackerel, salmon,
sardines or swordfish, may help prevent heart disease. That's one reason
why the American Heart Association currently recommends that everyone eat
at least two servings of fish on a weekly basis.
THE HOT TOPIC: TRANS FATS Trans fats are liquid vegetable oils that are
transformed via a process called "hydrogenation" into solids at room
temperature. This chemical process transforms healthy vegetable oils into
unhealthy fats that have been shown to raise LDL cholesterol.
In today's world of processed foods, more and more non-animal products
contain hydrogenated fats/oils, a source of trans fats - which actually
cause your body to make more cholesterol. Foods that contain trans fats
include margarines, vegetable shortening, partially hydrogenated vegetable
oil, countless fast foods (especially French fries), and most commercial
baked goods (crackers, donuts, potato chips, etc.).
The good news, if there is any, regarding trans fats is that as of 2006,
the Food and Drug Administration requires that food manufacturers list
amounts of trans fats on the nutrition information labels of products.
You've probably also noticed that increasing numbers of manufacturers now
make it clear that their products contain no trans fats.
THE EGG "CONTROVERSY" The egg is perhaps the ultimate cholesterol
question mark. On the one hand, eggs are a great source of important
nutrients, including vitamin D, vitamin B12, riboflavin and folate, that
may help reduce the risk of heart disease. They also provide high levels
of protein, iron and phosphorus.
However, since the 1960s, when the connection between cholesterol and
heart disease first became a public health concern, it was recommended
that egg consumption be restricted to only one egg per week. Why? Because
one large egg contains a whopping 213 milligrams of dietary cholesterol.
(The American Heart Association recommends limiting dietary cholesterol to
300 mg per day.)
But studies conducted at Harvard University found that people who ate one
egg per day were actually no more likely to develop heart disease or
suffer a stroke than people who ate one egg per week or less. The egg yolk
contains all the cholesterol (and fat), so limiting consumption of egg
yolks (to no more than four per week, according to the AHA's current
recommendation), and products that contain egg yolks, may be an important
aspect of managing cholesterol.
THE BOTTOM LINE When it comes to cholesterol, particularly with respect to
your diet, moderation is probably the best approach, whether it's eggs or
any other food that can affect cholesterol. Finding a healthy balance of
diet, exercise, weight management and stress reduction are vital steps in
winning the battle against high cholesterol.
Winning the Fight Against High Cholesterol
KNOW YOUR CHOLESTEROL SCORE. A simple blood cholesterol test will let you
(and your doctor) know your HDL, LDL and total cholesterol scores. If your
scores are good, you're on the right track; if they're not so good, your
doctor can help you get started on the road to better health.
KNOW WHAT YOU'RE EATING. Consume foods low in saturated fat and trans
fats, and high in omega-3 fatty acids and "good" fats (such as lean meats,
whole grains, and fruits and vegetables). Avoid processed foods and limit
your portion sizes.
KNOW YOUR FAMILY HISTORY. A genetic history of high cholesterol, high
blood pressure or heart disease can increase the risk of health problems.
It means you'll have to monitor your cholesterol more closely than the
EXERCISE DAILY. Just 30 minutes of physical activity a day can have a
positive impact on your cholesterol levels. By the way, it also helps with
weight control, prevention of numerous diseases, and can improve your
overall sense of well-being and health.
TALK TO YOUR DOCTOR. In extreme high-risk cases, your doctor may prescribe
cholesterol-lowering drugs in addition to lifestyle changes. But your
doctor should always pursue natural interventions, particularly diet and
exercise, before prescribing any type of medication.
Peter W. Crownfield is the executive editor of To Your Health. Direct all
comments and questions to firstname.lastname@example.org .