Cholesterol is fat like compound in its properties, found in animal’s bodies. It is synthesized by t liver for a number of vital biochemical and metabolic processes including:
- Maintenance of elasticity of body cells, as it is constituent of cell membrane.
- Production and secretion of various hormones and enzymes.
- Prevention of fatty acid related obstructions in cell membrane.
- Regulation of neurotransmission; facilitate the propagation of nerve impulse across the neurons.
- Bone calcification through vitamin D3 synthesis.
Major amount of cholesterol approximately 80% is synthesized by liver according to body need and remaining 20% is obtained from dietary sources for instance meat, poultry, full fat dairy products, palm oil, coconut oil, kernel oil, eggs (but they have least effect on blood cholesterol level) and all other food containing saturated and trans fats.
Excess of cholesterol just like everything is detrimental to health. In normal conditions, liver with its synthesis also plays role in its elimination; Surplus amount is converted into bile salts by liver and transported to bile, where overabundant bile is excreted through feces.
Transport of cholesterol from liver to target areas:
As cholesterol is fat like and insoluble in water, it demands fat soluble (non-polar) compound to be transported. Lipoprotein is a type of fat soluble protein that is engaged in transportation of cholesterol from liver to blood stream to reach the areas of its demand.
Types of lipoprotein:
Major types of lipoprotein include:
- Chylomicrons
- Very low density lipoprotein VLDL
- Low density lipoprotein LDL
- High density lipoprotein HDL
Chylomicrons:
These are lipids (fats) absorbed by enterocytes of small intestine. They accommodate 85-90% triglycerides; fetch lipids (fats) to body muscles in the form of energy rich molecule triacylglycerol, which is obtained by chylomicron under the action of lipoprotein lipase enzyme. This enzyme is present on surface of endothelial cells. Where they are either used by muscle cells for energy production or stored in adipose tissues. Chylomicrons transport exogenous fats, obtained from dietary sources.
Very low density lipoprotein:
This is synthesized by liver and is triglyceride copious form of lipoprotein. Supply cells with endogenous hepatic fatty acids and monoglycerides, under lipoprotein lipase enzyme activity, which can be diffused into cells and manipulate for oxidation processes.
Low density lipoprotein:
This is notorious as bad cholesterol. Its plenty is very injurious to health as it causes atherosclerosis, a condition in which blood arteries are blocked or narrowed by buildup of cholesterol, triglyceride and fatty acids. Excess VLDL is remolded into LDL by liver. LDL is involved in transportation of hepatic cholesterol to cells, where it is required for cell membrane and hormones production. Its abundance in body is called hypercholestremia.
High density lipoprotein:
It delivers cholesterol to intracellular spaces (between adjacent cells) for metabolic processes to take place in. This is well known to be beneficial for health because it abolishes excess amounts of all other bad lipoproteins by liver. HDL brings all other excess lipoproteins back to liver, by reverse cholesterol transport mechanism and eliminates by bile excretion through feces. So it’s necessary to maintain its healthy level, which will automatically reduce bad cholesterol.
MNT for hypercholestremia:
Hypercholestremia is characterized a high level of LDL & VLDL and low level of HDL in body. Here are some strategies to gain healthy HDL level:
- Consume monosaturated fat. (Coenzyme Q10 supplements).
- Restrict unsaturated or trans-fat.
- Consume omega 3 and 6 fatty acids. (Fish or fish oils)
- Ingest soluble fiber, having capacity to absorb cholesterol from intestine. (psyllium supplement).
- Lose weight in case of obesity to reduce stored fat in adipocytes.
- Be physically active for 30-60 minutes per day.
- Restrict smoking as it disturbs reverse cholesterol transport mechanism through blood vessels, under the action of tobacco and nicotine which is highly worsen to nervous system
- Use plant sterol and stanol, supplemented versions of HDL.