Cholesterol is one of the most misunderstood substances in the body. Usually, cholesterol is cast in a highly negative light due to the fact that it is a major risk factor for heart disease. While this is true, it is not the whole story. Cholesterol is actually a normal part of any healthy body, playing a vital role in your body's survival and maintenance. Without adequate amounts of cholesterol, your body would be unable to function properly.
Cholesterol and Fat Digestion
Almost all types of food contain fat, including fruits and vegetables; it is a highly valuable energy source. However, it cannot be dissolved in blood or water. The body therefore transports fat in the form of lipoproteins, which mix easily with blood, the Harvard School of Public Health explains. Lipoproteins are linked to cholesterol and are used to measure cholesterol in your body. There are three important types: low-density lipoproteins or LDL; high-density lipoproteins, or HDL; and triglycerides. Each type plays a different role in the body's vital systems.
Types of Lipoproteins
LDL, the so-called "bad cholesterol," transports fat and cholesterol from the liver to the rest of the body's cells. However, excess amounts of LDL can form plaque deposits in the arteries, which can lead to a heart attack or stroke, the University of Iowa Health Care notes. Meanwhile, HDL or "good cholesterol" carries excess cholesterol from the bloodstream and artery walls back to the liver for elimination. Lastly, triglycerides are the primary vehicle for moving fat to cells and make up the bulk of fat you eat. As with LDL, accumulating too many triglycerides is unhealthy.
Hormone Production
One of the most important roles of cholesterol is assisting in the production of certain hormones, the American Heart Association explains. These include glucocorticoids, mineralcortocoids and sex hormones. Glucocorticoids help to control blood sugar or glucose, an important energy resource for the body. Mineralcorticoids are essential in regulating the body's mineral levels and blood pressure. Finally, sex hormones such as estrogen and testosterone are required for normal physiologic development. Many diseases arise as result of a deficiency in these vital hormones.
Vitamin D Synthesis
Cholesterol acts as a precursor to vitamin D, "The New York Times Health Guide" notes. Vitamin D is known for its role in teeth and bone health and calcium metabolism. It also contributes to mental health, blood sugar regulation, maintenance of the immune system and cancer prevention. Most people know that dairy products and sunlight are important sources of vitamin D, but it is less commonly known that cholesterol is the third major factor. In fact, exposure to sunlight converts cholesterol in the skin into vitamin D. Lastly, food sources that offer vitamin D are exclusively animal foods that tend to be high in cholesterol content.
Cell Membrane Maintenance
Cholesterol is essential for building and maintaining cell membranes. These walls between cells are what lets them retain their shapes, regulate what passes into and out of the cells and allows the various types of cells to communicate with each other. Cholesterol is found between the water-attracting and water-repelling layers of cell membranes, acting as a gatekeeper for fluids that passes through the cell.
References
- American Heart Association: About Cholesterol
- Harvard School of Public Health: Fats and Cholesterol: Out with the Bad, In with the Good
- The New York Times Health Guide: Vitamin D
- The New York Times Health Guide: Cholesterol
- University of Iowa Health Care: Cholesterol is necessary for the body to function properly
