Cholesterol, a sterol found in animals with the formula C17H28O, is similar to ergosterol in fungi. These compounds play a crucial role in the human body and are involved in various processes, including cardiovascular disease. Drugs known as statins are used to lower cholesterol levels and reduce the risk of heart disease by acting on a pathway that constitutes the first 18 steps of the 37-step process used by the human body to make cholesterol.
Cholesterol is recycled in the human body through a mechanism that begins with its excretion from the liver and eventual reabsorption into the bloodstream in the small intestine. Under ultraviolet light, cholesterol is converted into calcitriol, an active form of vitamin D made in the kidneys. This compound plays an essential role in bone health and other important physiological processes.
In addition to its role in cardiovascular disease, cholesterol is also made and transported by cells called astrocytes for use in brain cells due to its ability to cross the blood-brain barrier. The discovery of cholesterol’s role in causing heart disease earned American biochemist Joseph Goldstein a Nobel Prize in Medicine shared with him by his collaborator Michael Brown.