Cholesterol is a form of lipid, or fat. It is a soft, waxing substance that is found in the bloodstream as well as the cells in our body. It is made out of a molecule called acetyl Co A that is derived from the breakdown of sugars, fats and proteins.
Approximately 80 percent of the cholesterol in our body is manufactured in our liver during the times when dietary fats are not available. This is usually about 8 hours after a meal. The remaining cholesterol is obtained through our diet.
Note that only food from animals contain cholesterol. Plant foods such as vegetables, fruits, nuts and vegetable oil do not contain cholesterol. The body makes much of its cholesterol out of saturated fats in food that we eat such as eggs and red meat. The body also makes cholesterol from the breakdown of sugar. If we eat too much sugar, starch and carbohydrates we will also end up with a lot of saturated fats in the body which is made into cholesterol.
Cholesterol has many vital functions in the body. It is required for building cell membranes and gives the membranes the rigidity and stablilty required. It is needed in the synthesis of the steroid hormones such as sex hormones estrogen, progesterone, DHEA and testerone and the synthesis of adrenal hormones like aldosterone and cortisol. Aldosterone regulates sodium and water balance in the body while cortisol regulates metabolism and supress imflamation.
Cholesterol produce bile salts that help in the digestion and absorption of dietary fats and fat soluble vitamins. It is needed for the synthesis of vitamin D which keep our bones strong, boost the immune system and keep the blood pressure normal. Getting some sun helps to lower cholesterol level by aiding its conversion to vitamin D.
Cholesterol is also required for protecting our skin. It is secreted into our skin and helps to cover and protect us from dehydration, cracking and drying. It helps in healing too as a high concentraion of it are found in scar tissue. Cholesterol is also necessary for the function of serotonin receptors in our brain. Serotonin helps to protect us from depression and several studies have shown that low cholesterol levels are associated with depression and violent behaviors.
Cholesterol is the main fats present in the myelin sheath which coats our nerve cells and enable vital neurological functions. A healthy myelin sheath is needed for good concentration and memory. Cholesterol also helps to transport fat soluble antioxidents such as vitamin A and E around our body.
Cholesterol is carried around our bloodstream in the form of lipoproteins which is essentially a combination of protein and fats. The main lipoproteins in our blood are Low Density Lipoproteins (LDL) also known as bad cholesterol, High Density Lipoprotein (HDL) also known as good cholesterol, Triglycerides and Lipoprotein (a).