What is cholesterol?
Cholesterol is a fatty substance — also known as a lipid — found in body tissues and blood that makes up an important part of the outer lining of cells. Cholesterol is the main precursor in the synthesis of many crucial hormones including vitamin D3 (the sunlight hormone); the steroid hormones cortisol, cortisone, and aldosterone in the adrenal glands; and the sex hormones progesterone, estrogen, and testosterone. Without cholesterol, we cannot live. It is crucial for hormone production and normal cell function. So, contrary to what you may have been told, cholesterol is not bad! Cholesterol is actually good and essential.
Cholesterol's delicate balance
When the body is dealing with health challenges and environmental stressors, blood vessels may become damaged due to daily wear and tear. Cholesterol actually helps maintain arterial health by sealing up the vessel walls. But, it's easy to imagine how excessive stress might lead to imbalance in this process and eventually result in cardiovascular and circulatory health challenges.
Normally, the body does a good job of balancing cholesterol. Cholesterol is constantly recycled and replenished by the liver and gallbladder. The liver recycles and replenishes cholesterol, while the gallbladder acts like a storage unit. When the body needs more cholesterol, the gallbladder is triggered to release its store.
What's the difference between LDL and HDL cholesterol?
The only way that cholesterol can flow through the body is by binding to proteins that carry it back and forth between the liver, gallbladder, and body cells. These are called high-density lipoproteins (HDL) and low-density lipoproteins (LDL). Think of them as taxis for cholesterol. High-density lipoproteins (HDL) are considered good because they carry cholesterol away from the arteries and back to the liver so it can be recycled. On the other hand, low-density lipoproteins (LDL) carry cholesterol away from the liver out to the cells that need cholesterol. Because low-density lipoproteins transport cholesterol to the arteries, an excess amount of LDL can eventually lead to health challenges in the arteries. That's why LDL cholesterol is sometimes called the "bad" cholesterol.
So what does that mean?
The goal of managing cholesterol is to essentially balance the traffic flow of cholesterol. By maintaining an appropriate ratio of "good" HDL cholesterol and "bad" LDL cholesterol, you create a smooth, steady flow of cholesterol for your body's cells.
When you hear all the talk about lowering total cholesterol, you're getting a vague, ambiguous message. That's because total cholesterol measures both HDL and LDL as one number. However, your total cholesterol number is only a small part of the picture and one that can be misleading. For example, if your good HDL level is high, and your bad LDL is low, your total cholesterol reading MAY still be high. But you might actually be in good shape, because your HDL and LDL are appropriately balanced. On the other hand, if your HDL is very low, and your LDL is high, your total cholesterol reading MAY be low. But your body may actually be dealing with a compromised cholesterol balance. The important measure of cholesterol is your HDL/LDL ratio. The key is to maintain an appropriate balance.