Cholesterol is a fat produced both by the liver and ingested through meats, eggs, and dairy products. Once it is formed, because it does not dissolve in water, it is carried through the bloodstream. It purpose is to help give flexibility to cell membrane and help cells decide what materials should and should not be able to penetrate the permeable cell walls. It is a necessary for the creation of bile used by the liver to break down fats and aid in the absorption of fat soluble vitamins. Cholesterol is the basic component of progesterone, estrogen and cortisol; a hormone released by the adrenal gland in response to stress.
All forms of cholesterol are a combination of fat, or lipid, and protein. Because the fats and sterols that make up cholesterol cannot be mixed with the water in blood, these fats are encased in protein particles called apolipoproteins. Besides containing cholesterol the protein encloses triglycerides and phospholipids which is used to hold everything together.
Cholesterol comes in a range of sizes: chylomicrons, very low-density lipoproteins, intermediate- density lipoproteins, low-density lipoproteins, high-density lipoproteins from largest to smallest. Chylomicrons, the largest, move fat through the blood from the intestine to the liver and to the fat tissue. Very low-density lipoproteins, VLDL, contain the highest level of triglycerides the fat stores by humans, collected from unused calories, and available for future use. Medical tests are used to estimate the level of this form of cholesterol is done by determining the triglyceride level in one’s blood. Intermediate-density lipoproteins, IDL, are created by the deterioration of VLDL after it has deposited its triglycerides to tissues and muscles, and the remainder is being returned to the liver. Low-density lipoproteins, LDL, often referred to as bad cholesterol is most often thought of the form that attaches itself to artery walls narrowing the area through which blood can pass, becomes inflamed leading white blood cells to attack, and creating plaque. The plaque can rupture and form a clot that causes a heart attack. High-density lipoproteins, HDL, or good cholesterol, travels through the blood stream absorbing LDL and returns cholesterol to the liver. HDL also dilates blood vessels, and lowers inflammation through antioxidants.
Although research is not conclusive, some experts believe that if LDL is too low the results can be: cancer, depression, anxiety, and premature birth or low birth weight for pregnant women. This problem is considered rare.