Understanding Cholesterol

What is Cholesterol?

Cholesterol is a lipid. Lipids are fats in the body.

Most people have been programmed to think that all fats are bad, however, fats are a key nutrient and your body needs them to function properly.  In fact, your body even makes them!

There are 3 forms of lipids (fats):

  • Triglycerides – the fats associated with fried foods, oil, and salad dressings.  These are the major fats found in your diet and made in your body.
  • Phospholipids – similar in structure to triglycerides, but they are made in the body and not needed in your diet.
  • Sterols – Made in the body and found only in food of animal origin. The most famous sterol is cholesterol.

The Functions of Cholesterol

Cholesterol gets a bad rap because of its role in heart disease.  It’s true that it does become a problem when too much accumulates in the blood. Most people don’t realize, however, that cholesterol is a necessary and important substance in the body.

Your Body Manufactures Cholesterol

Your body makes all it needs and cholesterol is not needed in the diet. In fact, it produces approximately 1,000 milligrams each day!

Some cholesterol is manufactured in all cells, but mostly in the liver and also in the intestines. It’s a major component in all of your cells, especially in nerve and brain tissue. Most cholesterol lives in your body tissue and not in the blood.

Cholesterol is a Manufacturer too!

Cholesterol is especially important in your body as it aids in the synthesis (formation) of Vitamin D and important hormones including testosterone and estrogen. Also, the liver uses cholesterol to manufacture bile salts, which play a major role in fat digestion.

Even the lens of the eye contains a high concentration of cholesterol, and cholesterol formation here may be essential for preventing cataracts.

Cholesterol in Selected Foods

From Nutrition Text, Fourth Edition.

Cholesterol in the Diet

Cholesterol is found only in animal foods. It’s highest in organ meats (brain, liver), moderate in muscle tissue and also found in dairy.

Notice as the fat content of dairy foods drops, so do the cholesterol levels.

Also the skeletal muscle (meat) from all kinds of animals have similar cholesterol regardless of fat content. Chicken, lean beef and lean pork are very similar in cholesterol levels.

What is Good and Bad Cholesterol?

Cholesterol can’t dissolve in the blood. It has to be transported to and from the cells by carriers called lipoproteins. Picture these lipoproteins as fat filled submarines which shuttle a combination of lipids throughout the body in the bloodstream. Low-density lipoprotein, or the LDL submarine, is known as “bad” cholesterol. It contains more than 50% cholesterol. High-density lipoprotein, or the HDL submarine, is known as “good” cholesterol and contains only 20% cholesterol.

Elevated LDL (bad cholesterol) in the blood increases the risk of heart disease. It can slowly build up in the inner walls of the arteries. Together with other substances, it can form a thick, hard deposit (plaque) that can narrow the arteries.

According to the American Heart Association, ‘HDL cholesterol is known as “good” cholesterol, because high levels of HDL seem to protect against heart attack. 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’.

Does Including Cholesterol in the Diet affect Cholesterol Production in the Body?

Increasing the cholesterol in your diet does reduce the cholesterol manufactured in the body, but not by an equivalent amount.  Eating small, frequent meals rather than a few large meals does inhibit cholesterol production somewhat.

How Do I reduce LDL Cholesterol?

This is a great question to ask your physician! Should you want more information before speaking with your doctor, an article by US News and World Report suggests that “to successfully reach your target levels it will probably take a combination of medication and lifestyle and dietary changes. Among the changes you’ll have to make: Stop smoking, work out, lose weight, and eat well”. The following link gives good information on changing your LDL and HDL levels.

http://health.usnews.com/health-conditions/heart-health/lowering-ldl-cholesterol#2

In Summary

Your body manufactures cholesterol and it plays an integral role in your body functioning properly.

Cholesterol only becomes an issue when too much accumulates in your blood.

Foods which contain cholesterol are of animal origin. (Vegetables, fruits and grains are naturally cholesterol free). If you wish to limit cholesterol in your diet, avoid eating animal organs (i.e. liver, brain). Also, choose low fat dairy products as the amount of cholesterol decreases along with the fat content.

Discuss your concerns of LDL and HDL cholesterol with your doctor.

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Sources:

Insel,P., Ross,D., McMahon,K., Bernstein,M., Nutrition Fourth Edition. Burlington: Jones & Bartlett, 2013

“Lowering LDL Cholesterol”, US News and World Report, http://health.usnews.com/health-conditions/heart-health/lowering-ldl-cholesterol#2

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