What Is Cholesterol?
Cholesterol is a waxy, fat-like substance that is made in the body by the liver. Cholesterol forms part of every cell in the body and serves a number of vital functions.
Sometimes, however, our bodies make more cholesterol than we need, and this excess cholesterol circulates in the bloodstream. High levels of cholesterol in the blood (hypercholesterolemia) can clog blood vessels and increase the risk for heart disease and stroke.
Our bodies make too much cholesterol when we eat too much saturated fat in our diet. Saturated fat is the kind of fat found in animal-based foods such as meat and dairy products.
We also get some cholesterol directly from animal-based foods in our diet such as meat, eggs, and dairy products. Plant foods such as fruits, vegetables, and grains do not contain cholesterol. Due to the high saturated fat content of the average diet, more than one-half of American adults have blood cholesterol levels that are too high.
Fortunately, most people can bring down their blood cholesterol levels without medication by changing their diet and by becoming more active. It’s worth remembering that for every 1 percent you lower your blood cholesterol level, you reduce your risk for heart disease by 2 percent. Furthermore, lowering cholesterol can help prevent heart attacks even if you already have heart disease.
Types of Cholesterol
There are 2 basic types of cholesterol:
- Low-density lipoprotein (or LDL) cholesterol is a bad type of cholesterol that is most likely to clog blood vessels, increasing your risk for heart disease. A diet high in saturated fat is a major dietary cause of raised LDL cholesterol.
- High-density lipoprotein (or HDL) cholesterol is a good type of cholesterol. HDL cholesterol helps clear the LDL cholesterol out of the blood and reduces your risk for heart disease. A diet rich in fruit and vegetables, with appropriate levels of omega-3/fish oil can help raise HDL cholesterol levels.
What Causes High Blood Cholesterol?
Several factors contribute to high serum cholesterol levels. Some of these cholesterol-risk factors are within your control, while some are not.
Cholesterol And Genetics
To some extent, your genes determine your cholesterol level. Some people inherit a condition called familial hypercholesterolemia, meaning, very high cholesterol levels run in the family. Other people, especially those with a family history of diabetes, inherit high triglyceride levels (hypertriglyceridemia). Triglycerides are another type of blood fat that can also raise cholesterol levels.
Cholesterol And Diet
Eating too much saturated dietary fat (the kind found in high-fat meats and dairy products) and cholesterol can cause your body to make more cholesterol, raising your blood cholesterol levels. You can lower your cholesterol level by switching to a lower-fat diet thus reducing intake of animal fat and other fats and eating foods rich in starch and fiber, such as fresh fruits, vegetables, and whole grains.
Cholesterol And Exercise
Regular exercise not only reduces total blood cholesterol, but it lowers the bad kind of cholesterol (LDL cholesterol) while raising the good kind of cholesterol (HDL cholesterol). With improved diet, exercise helps to reduce weight/obesity, another cholesterol-risk factor.
Cholesterol And Obesity
Being overweight contributes to rising blood cholesterol levels. Conversely, following an effective weight loss diet and losing weight can help reduce cholesterol levels.
Cholesterol, Smoking And Hormones
Smoking is an important risk-factor for raised blood cholesterol levels and heart disease. Meanwhile, women get a natural boost in their HDL cholesterol (the good kind of cholesterol) from their hormones until they reach menopause. After menopause, taking estrogen can help maintain higher HDL cholesterol levels.
High And Low Cholesterol Levels
Risk for heart disease and stroke increases with rising blood cholesterol levels. As blood cholesterol count exceeds 220 ml/dl (milligrams per deciliter-the units used to measure blood cholesterol in the United States), risk for heart disease increases at a more rapid rate.
If your blood cholesterol level is:
- Below 180 – your blood cholesterol level is ideal.
- 180-199 – your blood cholesterol level is acceptable.
- 200-219 – your blood cholesterol level is borderline high.
- 220 or higher – your blood cholesterol level is too high
If your total blood cholesterol level is greater than 200 (and especially if it is over 220), you should have another test to determine the individual levels of LDL cholesterol, HDL cholesterol and triglycerides.
NOTE: To understand how our digestive system digests and absorbs dietary fat, see Guide To Food Digestion and Digestion of Fats.