Cholesterol is a type of sterol, an organic compound that plays a crucial role in the human body. It is found in animals and classified as a zoosterol, while fungi have a similar compound called ergosterol. One class of drugs known as statins can lower cholesterol levels in the blood, reducing the risk of cardiovascular disease. These drugs work by blocking a specific pathway in the 37-step process used by the human body to make cholesterol.
Under ultraviolet light, cholesterol is transformed into calcitriol, an active form of vitamin D made in the kidneys. The human body has a mechanism to recycle cholesterol, which begins with its excretion from the liver and eventual reabsorption into the bloodstream in the small intestine.
Cholesterol is also present in brain cells called astrocytes because it cannot cross the blood-brain barrier. American biochemist Joseph Goldstein played a significant role in discovering the link between cholesterol and heart disease. He shared the Nobel Prize in Medicine in 1985 for his groundbreaking work on this topic.