You've probably heard about the dangers of having too much cholesterol in your blood. Indeed, elevated cholesterol levels can lead to the buildup of fatty plaques, a condition known as atherosclerosis. This is a risk factor for diseases such as heart disease and stroke, according to Mayo Clinic. However, cholesterol serves several important functions. Whether obtained from food or synthesized by your liver, cholesterol is essential to good health.
Cholesterol Sources
Dietary cholesterol is found exclusively in animal foods. Eggs, meat and dairy products are common sources of cholesterol in the average diet. According to the 2010 Dietary Guidelines for Americans, adults should consume under 300 mg of cholesterol per day. In fact, you do not need to consume any cholesterol, as your body is able to produce more than enough to meet the physiological and structural functions cholesterol provides.
Structural Functions
Cholesterol is a structural component of all cell membranes. The cell membrane surrounds the cell, maintaining its structure and regulating the passage of materials. Cholesterol helps to keep the membrane fluid and less susceptible to damage. Without enough cholesterol, your cells would be excessively permeable to water and other molecules causing them to rupture and leading to cell death. In the membrane, cholesterol also helps cells communicate with each other.
Hormone Synthesis
Cholesterol is also a precursor to many important hormones. Hormones are chemical substances secreted into your bloodstream in small amounts and delivered to target tissues, where they produce physiologic responses, according to the textbook "Physiology." Cholesterol is used to synthesize vitamin D, which helps your body regulate calcium levels and is important for a healthy immune system. In addition, the sex hormones testosterone and estrogen are derived from cholesterol. These hormones are active in the development of secondary sex characteristics, such as breasts in women and facial hair in man. The stress hormone cortisol, also comes from cholesterol. Cortisol is a potent anti-inflammatory.
Digestion
Cholesterol also plays an important role in the digestion of lipids, or fats. Specifically, your liver uses cholesterol to produce bile. Bile is stored in the gallbladder and released when you eat a meal containing fat. Bile helps make fat soluble so that your body can absorb it. Without enough bile, your body is unable to absorb and use dietary fat, a condition known as fat malabsorption, according to "Pathologic Basis of Disease." This is sometimes seen in individuals who have had their gallbladder removed.
References
- "Biochemistry"; Pamela C. Champe; 2005
- "Physiology"; Linda S. Costanzo; 2009
- "Pathologic Basis of Disease"; Vinay Kumar; 2005
- Dietary Guidelines for Americans 2010
- Mayo Clinic; High Cholesterol
