Cholesterol, a fat synthesized in the liver, is an essential component of every cell in the body and is beneficial for proper brain and nerve function (such as coordination and speech). Cholesterol makes up to 50% of the insulation cover around nerve cells. It is also the basis for the manufacture of sex hormones (estrogen, progesterone, testosterone, aldosterone etc.) which define the sex characteristics of an individual. Cholesterol is also necessary for the synthesis of vitamin D and bile acids. Bile acids’ function is to digest and absorb fats and fat soluble vitamins.

When is cholesterol bad?

Nonetheless, a high blood cholesterol level, especially elevated low-density lipoproteins (LDL), is considered a contributor to plaque build up in the arteries and impeded blood flow to the brain, kidneys, genitals, extremities, and heart. It is among the primary causes of heart disease, because cholesterol produces deposits in arteries. High cholesterol levels may also be implicated in gallstones, erectile dysfunction (although it is often the drugs prescribed to deal with high cholesterol that cause this), mental impairment, and high blood pressure.

Low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs)

Lipoproteins are composed of protein and triglycerides: with low-density lipoproteins containing 21% protein whereas high-density lipoproteins contain 50% protein. Low-density lipoproteins transport cholesterol from the liver to the rest of the body, and therefore low-density lipoproteins (LDLs) seem to encourage the deposit of cholesterol in the arteries,  which is the reason for the definition “bad cholesterol”. High-density lipoproteins (HDLs) on the other hand, are considered to be “good cholesterol” because they carry unneeded cholesterol away from the cells back to the liver, where it is broken down for removal from the body. If there are not enough High-density lipoproteins (HDLs) to pick up the excess cholesterol, cholesterol can form plaque that sticks to the arteries.

Cholesterol sources

The body produces its cholesterol, so even one does not eat cholesterol containing food, there is cholesterol in the blood stream. Causes of high serum cholesterol can be genetic, diet high in cholesterol and /or saturated fat. Factors that may lower cholesterol are vegetarian diet, regular exercise, the nutrients niacin and vitamin C.