Cholesterol: The Necessary Evil

We've all heard of cholesterol; we know from the glut of TV pharmaceutical ads that high cholesterol levels can increase our risk of heart attack or stroke , that high cholesterol can be an inherited condition; and that we may be able to keep our cholesterol at a healthy level with appropriate lifestyle changes or pharmaceutical drugs. We are aware that dietary cholesterol only comes from animal sources, including meat, fish, eggs, milk, cheese, and other dairy products. But how much do we really know about what cholesterol really is and how it affects our body's metabolism? You might be surprised to know that cholesterol is not "bad," in fact, it is a necessary substance our bodies use to keep us healthy.

The Natural Functions of Cholesterol

Cholesterol is a soft, waxy, fat-like substance that is found in our blood stream and all the cells of our bodies. Our liver naturally produces about three-fourths of the cholesterol in our bodies, and the rest comes from the food we eat. Cholesterol plays an important role in the repair of damaged cells and the production of new cells, in the formation of bile salts which help us digest fats, and in the production of Vitamin D.

Cholesterol is a substance required for the production of many steroid hormones, including testosterone, estrogen, DHEA, and cortisol. It provides the myelin lining for nerve fibers, helping to relay nerve signals more efficiently.

In the liver, cholesterol combines with compounds called apolipoproteins to form lipoproteins, which transport cholesterol to its destination. Low-density lipoproteins (LDL) are the "bad" cholesterol molecules that carry cholesterol from our liver to organs and body tissues. LDLs are unstable due to the low amount of proteins combined with cholesterol, and prone to breaking apart in the bloodstream. This free-floating cholesterol sometimes attaches itself to the walls of our blood vessels and combines with other substances to form plaque, a thick, hard deposit that narrows and stiffens our arteries and can cause blockages which can lead to heart attacks or strokes.

High-density lipoproteins (HDL) are "good" cholesterol molecules that carry excess cholesterol from our blood stream and various organs to the liver for recycling or destruction. These molecules are more stable due to the higher ratio of proteins to cholesterol. Some experts also believe that HDL can remove cholesterol from plaque deposits, and slow their growth. Since HDL is responsible for moving excess cholesterol to the liver, a low HDL level can increase your risk of stroke or heart disease even if you have an acceptable LDL level.

Although some people have an inherited tendency to create too much cholesterol in their liver, our lifestyle has a definite effect on our cholesterol levels. Diets high in sugar and fats, lack of exercise, being overweight, smoking, and even certain medications can raise our LDL cholesterol to an unhealthy level.

Debunking Cholesterol Myths

Let's clear up some common misconceptions about cholesterol:

"My diet and exercise habits are responsible for my cholesterol levels."
This is true to a degree, but some families have a mutation in their genes which are responsible for inherited high cholesterol. Even with proper diet and exercise, these family members may need medication to keep their LDL in line.

"You don't need your cholesterol level checked until you reach middle age."
It's a good idea to get your cholesterol checked the first time by age 20. Even children, especially those with a family history of high cholesterol and heart disease, can have high cholesterol levels. These children may be at higher risk for heart disease as adults. As parents, encourage your children to eat a heart-healthy diet and to get at least 30 minutes of physical exercise several days a week..

"High cholesterol is a man's problem."
Female hormones tend to raise HDL cholesterol which protects us from LDL cholesterol, but once we reach menopause our "bad" cholesterol tends to increase, and even a healthy diet and adequate exercise may not be enough to protect us.

"I'm taking cholesterol-lowering medications, so I don't have to watch my diet."
Whether through lifestyle modifications, cholesterol-lowering drugs, or a combination of both, keeping our HDL and LDL cholesterol at optimum levels allows the cholesterol in our bodies to perform its natural functions while decreasing our risk of coronary heart disease and stroke. While drug therapy is often prescribed for individuals who have not been able to lower their total cholesterol levels through diet and exercise, and some medications can target the LDL produced in our liver, it's still important to eat a heart-healthy diet.