Monday, October 12, 2009


If there is one biological material that has been widely condemned for its negative health impact on humans, it is cholesterol which occurs in different forms in the body. There are 'bad' cholesterol and 'good' cholesterol depending on how much protein is linked to it. HDL, the high density version has less of fatty component while LDL variety is low in proteins. The present theory is that LDL cholesterol is oxidized and becomes part of the plaques that clog the arteries affecting the functioning of the heart. Though there is no complete unanimity on the above theory, it is more or less accepted by the medical community and the multi billion dollar statin industry was borne. What is forgotten is that body has its own system for synthesizing cholesterol from its precursors and foods containing cholesterol may not influence critically the serum cholesterol levels under normal dietary practices. Why is that cholesterol literally evokes fear and apprehensions all around in spite of it being a natural metabolite?

On an average human body synthesizes about 1 gm a day in the liver, GI tract,adrenal glands and reproductive organs and total cholesterol content in the body can be as high as 35 gm in adult. Dietary intake on the other hand is hardly 200-300 mg a day and the homeostatic mechanism in the body regulates cholesterol synthesis, making less if dietary intake is more or vice-versa. It is a universal knowledge that cholesterol plays a versatile role in many biological functions which include building and maintaining cell membranes, regulating membrane fluidity, intracellular transport, cell signaling and nerve conduction. It is the vital precursor to bile salts which solubilizes fats in GI tract and aids intestinal absorption of fat molecules as well as fat soluble vitamins. Besides it is also a precursor to Vitamin D and important steroid hormones. Statin drugs are targeted at interfering with the synthesis of cholesterol by inhibiting the critical enzyme HMG-CoA Reductase thus reducing rate of in vivo synthesis but this enzyme has other functions which will also be affected by regular consumption of this commercial drug.

Recent reports, emanating from Sweden, suggesting that a derivative of cholesterol called Oxysterol is vital for development of brain cells, raises concern that aggressive reduction of cholesterol as is being proposed by some medical professionals can have disastrous consequences on brain development. Dopamine producing neurons during brain development seem to be dependent on activation of a specific receptor in the brain by Oxysterol which helps in producing safer and better dopamine producing cells. The observation that in people afflicted by Parkinson's disease the dopamine producing cells die faster, lends credence to the above findings. While statins are useful in treating genetically predisposed high cholesterol patients or those with metabolic aberrations, the practice of its wide scale use to drastically bring down the level in normally healthy persons in the name of preventing atherosclerosis needs to be reviewed because of its possible impact on brain development and function and increased incidence of Parkinson's disease.


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