CHOLESTEROL AND HEART DISEASE
Introduction
Anyone can have high cholesterol- even if you are active or thin, young or old. In fact 1 in 5 people already does. And since high cholesterol may be part of your genetic makeup, even if you eat right and exercise, you might need some help in controlling it. Even if you eat right and exercise, your cholesterol levels might still be high. About half of all Americans have a higher-than-desirable blood cholesterol level (hypercholesterolaemia). If you're one of these people with this largely preventable condition, you may be on the way to heart disease. Too much animal fat and a high cholesterol is dangerous to your heart and vessels. A high blood cholesterol is said to promote atherosclerosis (the scientific name for arteriosclerosis) and thus also coronary heart disease. But many studies have shown that people whose blood cholesterol is low become just as atherosclerotic as people whose cholesterol is high.
In
the next paragraphs you will find a comprehensive but simple-to-understand
explanation of how blood lipids (LDL, HDL, triglycerides) and free radicals
affect your risk of developing cardiovascular diseases. Also you will find out
the different factors affecting your cholesterol level and also the traditional
treatments and managements for high cholesterol (hypercholesterolemia).
Discussion
Cholesterol is an odorless soft waxy substance that is present in all parts of the body, including the brain and nervous system,
muscle, skin liver and intestines, heart, skeleton, etc. It is made by the body and obtained from animal products in the diet.
Cholesterol is one of several types of fats (lipids) that are essential to good health. Because of its reputation as a risk factor for
heart disease, people tend to think of cholesterol only in negative terms. But cholesterol is an important component of cell membranes
and vital to the structure and function of all of your body's cells. Cholesterol also is a building block in the formation of certain types
of hormones and production of many vitamin D, and bile acids, which are important for the absorption of fat. Your body needs
cholesterol to function normally.
Your body produces three to four times more cholesterol than you eat. The production of cholesterol increases when you eat little cholesterol
and decreases when you eat much. This explains why the "prudent" diet cannot lower cholesterol more than on average a few per cent. Dietary
cholesterol is found only in foods of animal origin (not in foods of plant origin) both high fat foods and low fat foods. Foods of plant origin
(vegetables, fruits, grains, cereals, nuts, and seeds) contain no cholesterol. Cholesterol is found in eggs, dairy products, hotdogs, meat, poultry,
fish, and shellfish. And the amount of cholesterol in these foods varies. A daily intake of less than 300 mg is recommended. A three ounce piece
of meat, fish, or poultry has 60 to 90 mg of cholesterol; one egg yolk contains about 270 mg; and a three ounce serving of liver has about 390 mg
of cholesterol. Fish generally contains less cholesterol than other meats, but some shellfish is high in cholesterol content. Fat content is not a good
measurement of cholesterol content. For example, liver and other organ meats are low in fat but very high in cholesterol. Most varieties of seafood
are healthily low in cholesterol although some shellfish, namely squid and prawns, are rich in cholesterol. This does not mean that you have to eliminate
them from you diet completely. It is certainly possible to enjoy all types of seafood but stay within the recommended cholesterol intake per day.
A 100 g serving of squid contains 200 - 250 mg of cholesterol while a 100 g serving of prawns contains between 130 - 150 mg. If you are eating these foods,
keep the amount you consume to a reasonable quantity (a 100 g serving would be about right) and save other cholesterol-rich foods such as eggs, beef or
liver for another day. Also remember that the more fat consumed at the same time, the more easily the cholesterol is absorbed. Keep dishes as low in fat as
possible and choose your cooking methods wisely, opting for steaming, poaching or stir-frying over deep fat frying.
Cholesterol is not a deadly poison, but a substance vital to the cells of all mammals. A high cholesterol is not dangerous by itself, but may reflect an unhealthy
condition. Your blood cholesterol level is affected not only by the saturated fat and cholesterol in your diet, but also by the cholesterol your body produces.
As a matter of fact, your body produces all the cholesterol it needs, and the saturated fat and cholesterol in your diet only serve to increase your blood cholesterol
levels. Cholesterol and blood do not mix well. So, for cholesterol to travel through your blood, it is coated or packaged with a layer of protein and large molecules
of fat to make lipoprotein. All lipoproteins are formed in the liver and carry cholesterol through out the body. Since cholesterol and triglycerides are fats, they will
not dissolve in water. To circulate in your blood, which is mainly water, cholesterol and triglycerides must be carried by proteins called apoproteins. A lipoprotein
is a combination of a lipid and an apoprotein. .A person's cholesterol "number" refers to the total amount of cholesterol in the blood. Cholesterol is measured in
milligrams per deciliter (mg/dl) of blood (A deciliter is a tenth of a liter.) Doctors recommend that total blood cholesterol be kept below 200 mg/dl.
The average level in adults in this country is 205 to 215 mg/dl.
The main types of lipoproteins are Very Low-density Lipoprotein (VLDL), Low-density Lipoprotein (LDL), High-density Lipoprotein (HDL).
Very-low-density lipoprotein (VLDL). This type of lipoprotein contains mostly triglycerides and small amounts of protein and cholesterol.
Low-density lipoprotein (LDL) contains about 25 percent protein and 45 percent cholesterol. Blood cholesterol packaged in Low-density lipoproteins (LDLs)
is transported from the liver to other parts of the body where it can be used. The cholesterol carried in LDL particles is known as LDL cholesterol and most
cholesterol is of this type. LDL cholesterol carries most of the cholesterol in the blood and transported to tissues, where it's either deposited or used to
repair membrane and if not removed from the blood, LDL cholesterol promotes accumulation of cholesterol and fat in the walls of your arteries, where it
mixes with other substances to form a plaque. This build of cholesterol plaque thickens and stiffens artery walls inhibiting blood flow contributing to
atherosclerosis. The resulting partial blockade of a coronary artery may cause chest pains, complete blockade may results in a heart attack. Thus, the more
LDL you have in your blood, the greater your heart disease risk. Lowering elevated LDL cholesterol can reduce the risk of having a heart attack. This is why
LDL cholesterol is often called "bad cholesterol". LDL levels should be less than 130 mg/dl and ideally less than 100 mg/dl. Like total cholesterol. LDL levels
can be reduced by decreasing saturated fats and cholesterol in the diet.
Cholesterol is also packaged in a high density Lipoproteins (HDLs). HDL contains almost 50 percent protein and 20 percent cholesterol. The cholesterol
carried in HDL particles is known as HDL cholesterol. HDL-cholesterol, helps your body get rid of the cholesterol in your blood. Thus, if your levels of
HDL are low, your risk of heart disease increases. HDLs carry cholesterol back to the liver for reprocessing or excretion from the body. HDLs, therefore,
help to remove extra cholesterol from the blood, preventing the accumulation of cholesterol in the walls of the arteries, thus may help to reduce your risk
of coronary heart disease. That's the reason how HDL has earned the nickname "good
cholesterol".
LDL and HDL levels provide information on your risk of developing coronary heart disease. Having a low level of LDL cholesterol and a high level of HDL
cholesterol is desirable for lowering your risk of developing plaques and coronary artery disease. A high LDL cholesterol level or a low HDL cholesterol
level (below 35 mg/dl) puts you at increased risk, even if the total cholesterol level is in the desirable range. LDL and HDL cholesterol levels more accurately
predict your risk for coronary heart disease than a total cholesterol level alone. But the relative amount of HDL to total cholesterol is also important, the amount
of HDL should be at least one-quarter of the cholesterol level. You may have high LDL cholesterol as a result of genetic makeup or lifestyle choices, or both.
Your genes can give you cells that don't remove LDL cholesterol from your blood efficiently, or a liver that produces too much cholesterol as VLDL particles.
Your genetic makeup also can result in too few HDL particles.
Triglycerides or TG, fats that circulate in the bloodstream, come from food and also are manufactured by the body, primarily the liver. Triglycerides are another
form of fat that moves through your blood as transportable fuel used for energy. High levels of circulating TG are believed to be predictive of heart disease.
The normal range is between 50 and 200 mg/dl. More than 400 is considered high, while very high levels - above 1,000 - indicate a high risk of a life-threatening
inflammation of the pancreas. Triglyceride levels increase after eating, especially if the meal is high in fats and carbohydrates. They also increase with excessive
alcohol intake and smoking. Certain medications for heart problems raise TG levels as well.
High blood cholesterol is a serious problem, it is a "risk factor" for heart disease. When the levels of cholesterol and triglycerides, another blood fat, in your
bloodstream become too high, your likelihood of developing cholesterol-containing fatty deposits (plaques) in your blood vessels increases. Over time, plaques
narrow or block arteries, impeding blood flow and creating a condition called atherosclerosis. Atherosclerosis is a silent, painless process that results in reduced
blood flow. If reduced flow occurs in the arteries around your heart (coronary arteries), it can lead to a type of chest pain called
angina pectoris. As a plaque enlarges,
the inner lining of your artery becomes roughened. A tear or rupture in the plaque may cause a blood clot to form. Such a clot can block the flow of blood or break free
and plug an artery downstream. If the flow of blood to a part of your heart is stopped, you'll have a
heart attack. If blood flow to a part of your brain stops, a stroke is imminent.
Also, narrowing of the arteries around your heart (coronary artery disease) can prevent your heart from getting as much oxygen-rich blood as it needs. This means an increased
risk of a heart attack. Likewise, decreased blood flow to you brain can cause a stroke, and less blood flowing to your lower limbs may result in
gangrene. Cholesterol plays a
significant role in this largely preventable condition.
That means that having high blood cholesterol increases your chance, or risk, of getting or developing
heart disease or atherosclerosis. And heart disease is the
number one killer of both men and women. Among the factors which affects the blood cholesterol levels that you can do something about,
diet has the largest effect on your blood
cholesterol level. Saturated fat and trans fat raises your blood cholesterol level. Dietary cholesterol also increases your blood cholesterol level, thus it raises total and LDL-cholesterol level.
Polyunsaturated fats lower blood cholesterol but also seem susceptible to oxidation. Over time, oxidation speeds buildup of plaques inside your arteries. Monounsaturated fats may
help lower blood cholesterol and are resistant to oxidation. If you have high blood cholesterol, inhibiting the take of dietary fat and cholesterol into your system will be a very important step to
take place. Being overweight may also increase your blood cholesterol level, increases triglycerides. It makes your LDL-cholesterol level go up and your HDL level go down.
Most overweight patients with high levels of cholesterol can help control their cholesterol levels by weight reduction. Lifestyle choices can cause or contribute to high total
cholesterol levels. Increased physical activity or exercise helps to lower LDL-cholesterol and raise HDL-cholesterol levels. Also heredity will influence your blood cholesterol levels.
Your body makes all the cholesterol it needs, and your genes influence how your body makes and handles cholesterol. If a close family member (parent or sibling) has developed
atherosclerosis before age 45, high cholesterol levels place you at a greater risk than average of developing atherosclerosis . Another factor is your
age and gender. Blood cholesterol
levels in both men and women begin to go up at about age 20.Women before menopause have levels that are lower than men of the same age. After menopause, woman's
LDL-cholesterol level goes up -- and so does her risk for heart disease. Cigarette smoking damages the walls of your blood vessels, making them prone to accumulate fatty deposits.
Smoking also may lower your level of HDL cholesterol by as much as 15 percent. By damaging the walls of your arteries,
high blood pressure can accelerate the accumulation of fatty
deposits on the walls of your arteries. Type 2 diabetes generally develops after age 40. The condition results in a buildup of sugar levels in your blood. Chronic high blood
sugar may lead to narrowing of your arteries.
Anyone can develop high blood cholesterol regardless of age, sex, race or ethnic background. Like high blood pressure, it is a potential threat to your health that you can do
something about. High cholesterol is one of the major risk factors for coronary heart disease and being overweight also contributes significantly to this problem.
High blood cholesterol occurs when there is too much cholesterol in your blood. Your cholesterol level is determined partly by your genetic makeup and the
saturated fat and cholesterol in the foods you eat. Even if you did not eat any cholesterol, your body would manufacture enough for its needs.
Most coronary heart disease is caused by arteriosclerosis, which occurs when cholesterol, fat, and other substances build up in the walls of the arteries that
supply blood to the heart. These deposits narrow the arteries and can slow or block the flow of blood. Among many things, blood carries a constant supply
of oxygen to the heart. Without oxygen, heart muscles weaken, resulting in chest pain (angina), a heart attack (myocardial infarction), or even death.
Arteriosclerosis is a slow progressive disease that may start very early in life yet, may not produce symptoms for many years.
Conclusion
Controlling body weight and cholesterol levels are keys to a healthy cardiovascular system. Therefore a consistent health plan to control body weight
and cholesterol levels is needed. Effective screening for and management of hypercholesterolemia will make a significant contribution to the prevention
of coronary heart disease. In assessing your risk for heart disease, your blood lipid profile is more important than your profile in the mirror. If you have
never had your blood cholesterol measured, it's a good idea to do so, and to get it rechecked every five years. If you are older than 70, the importance of
blood cholesterol levels are more controversial.
A good way to detect high blood cholesterol early so that you can take steps to improve your health is to have a regular blood test to measure your
cholesterol level. Some doctors recommend having your levels of high-density lipoprotein (HDL) cholesterol - the so-called good cholesterol - and of
triglycerides, another type of blood lipids, measured initially, as well as your total cholesterol level. A typical blood cholesterol test measures: total cholesterol,
HDL cholesterol, triglycerides. Values for low-density lipoprotein (LDL) cholesterol can be calculated from the other three values, providing a good estimate.
Measuring only total cholesterol can be misleading because some people have low levels of HDL cholesterol and high levels of triglycerides, but normal or
even high levels of LDL cholesterol. In these cases, a total cholesterol measurement might appear normal. You and your doctor would be unaware of the
risk of heart disease posed by the abnormal levels that weren't measured. Even with a desirable total cholesterol level, if you have a low HDL level, you may
be at increased risk for heart disease. Desirable ranges for cholesterol levels vary depending on risk factors such as your age, gender, family history and
health condition. There's no magic number that separates risky levels from safe levels. Rather, expert investigators and doctors have identified levels of
lipids in the blood above which the risk for developing coronary complications is high enough to warrant lifestyle changes.
The risk of developing coronary heart disease increases as your blood cholesterol rises. This is why it is so important that you have your cholesterol
level measured. "Desirable" blood cholesterol levels are considered by most experts to be less than 200 milligrams per deciliter (mg/dl) because they
carry the least risk of heart disease while levels of 240 mg/dL or above are considered
"high" and require more specific attention because this is associated
with an increased risk for coronary heart disease. Levels from 200-239 mg/dL also require attention especially if your HDL-cholesterol is low or if you have
two or more other risk factors for heart disease. If you're healthy:Total cholesterol: Below 200 milligrams per deciliter (mg/dL); total triglycerides: Below 200
mg/dL; HDL cholesterol: Above 45 mg/dL; LDL cholesterol: Below 130 mg/dL. If you have coronary artery disease: Total cholesterol: Below 200 mg/dL;
Total triglycerides: Below 200 mg/dL; HDL cholesterol: Above 35 mg/dL; LDL cholesterol: Below 100 mg/dL.
Lowering your high blood cholesterol level will slow fatty build up in the walls of the arteries and reduce your risk of a heart attack and death caused by
heart attack. In fact, some studies have shown that in adults with "high" cholesterol levels, for each one percent reduction in total cholesterol levels, there
is a two percent reduction in the number of heart attacks. In other words, if you reduce your cholesterol level 15 percent, your risk of coronary heart disease
could drop by 30 percent.
Lifestyle changes are the first steps to take to improve your blood levels of cholesterol and triglycerides. These steps include changes in diet, exercising regularly
and not smoking. But if you've made these important lifestyle changes and your total cholesterol - especially your level of low-density lipoprotein (LDL)
cholesterol - remains high. It is also important to know the levels for High Density Lipoprotein (HDL, also known as the "good cholesterol") and Low Density
Lipoprotein (LDL, or "bad cholesterol"). HDL-Cholesterol. Unlike total and LDL-cholesterol, the lower your HDL, the higher your risk for heart disease.
An HDL level less than 35 mg/dL is considered low and increases your risk for heart disease. The higher your HDL, the better. An HDL level of 60 mg/dL
or above is high. Your LDL level gives a better picture of your risk for heart disease than your total cholesterol. Your LDL cholesterol level is usually the
deciding factor. Lowering LDL is the main aim of treatment for a cholesterol problem. If your LDL level puts you at high-risk and you have fewer than two
other risk factors for heart disease, then your treatment goal is an LDL level of less than 160 mg/dL. However, if you have two or more other risk factors for
heart disease, your LDL goal should be less than 130 mg/dL. If you already have heart disease, your LDL should be even lower -- 100 mg/dL or less.
The liver also makes cholesterol for hormonal purposes as a response to stress. It is possible to decrease cholesterol by decreasing and managing stress.
Diet and exercise are first-line therapy for high cholesterol, but they may not be enough to bring your cholesterol down to a healthy number. In a recent
study, diet and exercise lowered total cholesterol by 7%-9%.Therefore exercise and stress management are an important part of a cholesterol lowering plan.
Improving your blood cholesterol levels reduces your risk of heart disease. Lifestyle steps are your first course of action to improve your blood cholesterol
levels. These steps include eating a healthy diet, exercising and not smoking.
The greatest dangers to your health are directly related to your eating
habits. People eat for taste and convenience, not for health and nutrition, and because
of this we are contributing to the greatest health problem facing our society today.�heart disease! To lower high cholesterol levels, eat less than 30% of the
total daily calories from fat. Of that 30%, less than one-third should be from saturated fat and not more than one-third should be from polyunsaturated fat. At
least one-third of the total fat calories should be from monounsaturated fat . Less than 300 milligrams (mg) of dietary cholesterol per day should be consumed.
Eating a healthy diet. These changes in your diet can improve your blood cholesterol levels: Control total fat . Limit all types of fat - saturated, polyunsaturated,
trans fatty acids (trans fats) and monounsaturated - to no more than 30 percent of your total daily calories. Because all foods with fats contain a combination
of these fats, it's important to reduce total fat. By balancing occasional high-fat foods with low-fat choices, your fat intake should average no more than
30 percent of your daily calories. If your daily intake is 2,000 calories, 30 percent equals 65 grams of fat. Limit dietary cholesterol . Your daily limit for dietary
cholesterol is 300 milligrams. To accomplish this goal, limit or avoid concentrated sources such as organ meats, egg yolks and whole milk products. Eat foods
with soluble fiber. As part of a low-fat diet, soluble fiber can help lower your total blood cholesterol level. Foods high in soluble fiber include oat bran, oatmeal,
beans, peas, rice bran, barley, citrus fruits, strawberries and apple pulp. Eat more fish . Some fish - particularly fatty types prevalent in cold water such as salmon,
mackerel and herring - contain high amounts of a unique type of polyunsaturated fat called
omega-3 fatty acids. Omega 3s may lower your level of triglycerides.
Consider soy products . Soy compounds called isoflavones act like human hormones that regulate cholesterol levels. Eating soy proteins can reduce your levels
of total cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides. Eating soy may also raise your level of high-density lipoprotein (HDL)
cholesterol - "good" cholesterol, which may protect you against heart disease. Eat more foods with antioxidants .
Antioxidant vitamins may help prevent cholesterol
from damaging the lining of your arteries. They include vitamins C and E and the carotenoids, such as beta carotene. Oxidation is the process by which cells in your
body called free radicals damage other cells as they seek to replace their missing electron. Antioxidants neutralize free radicals by donating the electrons the free
radicals need. Oxidation causes changes in fatty acids and LDL cholesterol in your blood. These changes enable cells in your arteries to absorb fatty acids and
LDL cholesterol more easily, leading to plaque buildup and narrowing of your arteries.
Drink alcohol in moderation. Moderate consumption of alcohol
may raise your level of HDL cholesterol. Limit alcohol to one drink daily if you're a woman, to no more
than two drinks daily if you're a man. If you're a nondrinker, don't start drinking alcohol. Don't drink alcohol if you have a high level of triglycerides.
Being overweight promotes a high total cholesterol level. Losing weight improves your cholesterol levels. Set up an exercise program to lose weight using
these guidelines and your doctor's advice: Choose an aerobic activity. Get involved in activities such as brisk walking, jogging, bicycling or cross-country
skiing. Build up the time and frequency of exercising. Gradually work up to exercising for 30 minutes to 45 minutes at least three times a week. If you're
significantly overweight or have been inactive for many years, take several months to gradually work up to this level. The higher the level of your activity,
the greater your rate of weight loss. Stick with your exercise program. Schedule a regular time for exercise.
Not smoking. If you smoke, stop. If you don't smoke, don't start. Cigarette smoking damages the walls of your blood vessels, making them prone to accumulate
fatty deposits. If you stop smoking, your HDL cholesterol may return to its former level.
Even if you eat right and exercise, your cholesterol levels might still be high. That's why many doctors today are prescribing
medication in addition to diet and
exercise for some people as part of their treatment plan to help lower high cholesterol. These are the medications available to improve blood cholesterol levels
include: Resins. The medications cholestyramine (Questran) and colestipol (Colestid) lower cholesterol indirectly by binding with bile acids in your intestinal tract.
Your liver makes bile acids, which you need for digestion, from cholesterol. By tying up bile acids, resins prompt your liver to make more bile acids. Because your
liver uses cholesterol to make bile acids, less cholesterol is available to reach your bloodstream.
Triglyceride lowering drugs. These medications include fibrates
such as gemfibrozil (Lopid) and fenofibrate (Tricor), and niacin (nicotinic acid).
Niacin. Large doses of niacin, a vitamin, also can lower triglycerides.
In addition, niacin can lower LDL cholestero and increase HDL cholesterol, both
beneficial effects. Fibrates reduce triglyceride production and remove triglycerides from circulation.
They often also increase your HDL cholesterol level. Statins. Statins
also known as HMG-CoA reductase inhibitors which work directly in your liver to block a substance your liver needs to make cholesterol. This
depletes cholesterol in your liver cells, which causes your liver cells to remove cholesterol from your blood. Statins can reduce your LDL cholesterol by up to
40 percent. Statins also may help your body reabsorb cholesterol from plaques that accumulate on the walls of your arteries. This process slowly unplugs
your blood vessels. Statins include fluvastatin (Lescol), lovastatin (Mevacor), simvastatin (Zocor), pravastatin (Pravachol) and atorvastatin
(Lipitor).
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