Cholesterol is a type of sterol found in animals and has the formula C17H28O. Fungi also have a similar compound called ergosterol, which plays a role similar to cholesterol.
Cholesterol is known to increase the risk of cardiovascular disease, which is why drugs called statins are used to lower cholesterol levels in the blood. These drugs work by blocking a pathway that is responsible for making cholesterol in the body. By inhibiting this process, statins reduce the amount of cholesterol in the bloodstream.
Under normal conditions, when exposed to ultraviolet light, the body converts cholesterol into calcitriol, an active form of vitamin D made in the kidneys. Calcitriol plays a crucial role in bone health and helps regulate calcium levels in the body.
The human body has a mechanism for recycling cholesterol, starting with its excretion from the liver and eventual reabsorption into the bloodstream in the small intestine. This process helps maintain healthy cholesterol levels in the body.
Cholesterol is also found in high concentrations in brain cells called astrocytes because it can’t cross the blood-brain barrier. Astrocytes transport cholesterol through their cell bodies and use it to support various functions such as neural communication and energy production. In 1985, American biochemist Joseph Goldstein shared the Nobel Prize in Medicine with his colleagues for their discovery of this relationship between cholesterol and brain function.