is a lipid (fat) which is produced by the liver. Cholesterol is vital for normal body function. Every cell in our body has cholesterol in its outer layer.
Cholesterol is a waxy steroid and is transported in the blood plasma of all animals. It is the main sterol synthesized by animals - small amounts are also synthesized in plants and fungi. A sterol is a steroid sub-group.
The word "cholesterol" comes from the Greek word chole, meaning "bile", and the Greek word stereos, meaning "solid, stiff".
Cholesterol in our body performs the following functions
What are normal cholesterol levels?
- Cholesterol is required to build and maintain cell membranes.
- It converts sunshine to vitamin D, which among other things is said to have cardiovascular benefits.
- It insulates nerve fibers.
- It modulates membrane fluidity over the range of physiological temperatures.
- It aids in production of bile.
- It helps solubilize fats in the digestive tract and aid in the intestinal absorption of fat molecules as well as the fat-soluble vitamins, A, D, E, and K
- Cholesterol is involved in production of sex hormones progesterone, estrogen, and testosterone, and their derivatives.
The amount of cholesterol in human blood can vary from 3.6 mmol/liter to 7.8 mmol/liter.
Below is a list of cholesterol levels and how most doctors would categorize them
in mg/dl (milligrams/deciliter) and 5mmol/liter (millimoles/liter).
Dangers of high cholesterol levels
- Desirable - Less than 200 mg/dL.
- Bordeline high - 200 to 239 mg/dL.
- Optimum level: less than 5 mmol/liter.
- Mildly high cholesterol level: between 5 to 6.4 mmol/liter.
- Moderately high cholesterol level: between 6.5 to 7.8 mmol/liter.
- Very high cholesterol level: above 7.8 mmol/liter.
- High - 240 mg/dL and above.
High cholesterol levels can cause:
Atherosclerosis - narrowing of the arteries.
Higher coronary heart disease risk - an abnormality of the arteries that supply blood and oxygen to the heart.
Heart attack - occurs when the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in a coronary artery. This causes your heart muscle to die.10
Angina - chest pain or discomfort that occurs when your heart muscle does not get enough blood.
Stroke and mini-stroke - occurs when a blood clot blocks an artery or vein, interrupting the flow to an area of the brain. Can also occur when a blood vessel breaks. Brain cells begin to die.12
If both blood cholesterol and triglyceride levels are high, the risk of developing coronary heart disease rises significantly.
What causes high cholesterol?
Nutrition - although some foods contain cholesterol, such as eggs, kidneys and some sea foods, dietary cholesterol does not have much of an impact in human blood cholesterol levels. However, saturated fats do have a huge impact on the human blood cholesterol levels. Foods high in saturated fats include red meat, some pies, sausages, hard cheese, lard, pastry, cakes, most biscuits, and cream (there are many more).
Sedentary lifestyle - people who do not exercise and spend most of their time sitting/lying down have significantly higher levels of LDL (bad cholesterol) and lower levels of HDL (good cholesterol).
Body weight - people who are overweight/obese are much more likely to have higher LDL levels and lower HDL levels, compared to those who are of normal weight.
Smoking - this can have quite a considerable effect on LDL levels.
Read More on
cholesterol at Harvard UniversityCauses of Heart DiseasesFats & Cholesterol