Comments on: What is the difference between "good" cholesterol and "bad" cholesterol? Why do we have cholesterol, anyway?

By: Fyysikko

Fyysikko — Sat, 30 May 2009 21:05:59 +0000

Cholesterol is a steroid alcohol essential for cell membrane structures. It's everywhere in our bodies and the "starting point" to create steroid hormones like estrogen.
Even though cholesterol is essential, it is also possible to get too much of it. Our bodies produce it but we also get it from food. In blood and tissue fluids, cholesterol remains dissolved thanks to proteins around it. That's when lipoprotein complexes are formed. They are small particles that might have other lipids in them. These particles are called VLDL, LDL, HLD, etc. (very low density lipoproteins, low density lipoproteins, high density lipoproteins etc.) LDL is the "bad one" whereas HDL is the "good one". The reason for why LDL is bad is that with LDL, cholesterol moves into cells and to the artery walls and might remain there. That in turn might cause an infiltration of fat.
HDL in turn is able to pick up all that bad cholesterol from arteries.
So cholesterol is very important, we need it to make androgens, estrogens, progesterone, cell membranes etc. However, our bodies just have a limited capacity to decrease its own cholesterol production and thus we should pay attention to the amount we get in food.
Hope this helps…
References :
Biologian sanakirja (Tirri, Lehtonen… Otava 2001)

By: J

Sat, 30 May 2009 20:47:59 +0000

HDL – High Denisty Lipoprotein (protein and fat) HDL takes cholesterol out of the blood and back to the liver for recycling.

LDL – Low Density Lipoprotein LDL takes cholesterol from the liver into the blood stream.

Cholesterol comes from the gut (diet) and the liver (genetics). Some people could eat literally cardboard and still have high cholesterol. Others (not many, mind you) could eat pure cholesterol and have normal levels.

The problem is that certain varieties of LDL cause an inflammatory reaction in the walls of blood vessels. This causes plaque to form. When the plaque breaks, a clot forms and can flick off to other parts of the body, ie brain (Stroke) and heart (MI, or heart attack). Thus, the lower the LDL, the better.
References :

By: miles_dyosa

miles_dyosa — Sat, 30 May 2009 20:19:59 +0000

Cholesterol is a soft, fatty, waxy substance found in the blood and in body cells. in fact, your body even manufactures cholesterol! it makes up the cell membrane, or the outer covering of cells that selects what goes in and out of the cells.
but anything in excess is bad. too much of it in the blood can cause major heart problems like hypertension and coronary heart disease.

cholesterol is transported by carriers found in the bloodstream. these carriers are called lipoproteins.

the high-density lipoprotein (HDL) and the low-density lipoprotein (LDL), the ones we refer to as "good" and "bad" cholesterol respectively.

cholesterols and other fats do not dissolve in the blood, but are instead transported to parts of the body. this is why LDL or the low-density lipoprotein is called the bad cholesterol. it sticks to the walls of the arteries together with other substances forming a buildup called plaque which narrows the passageway of the blood. this condition is called artherosclerosis. since the passageway of the blood is narrower than before, the blood pumped to certain areas of the body lessens. if a vein or artery leading to the brain is blocked, it can cause a stroke. this type of cholesterol is mostly found in animal fats.

HDL or high-density lipoprotein on the other hand,is called good because this carrier doesn't stick to the walls of the artery. About one-third to one-fourth of blood cholesterol is carried by high-density lipoprotein.medical researchers found out that a high level of HDL's lower the risk of heart attack. high density cholesterol carry the cholesterol away from the heart and transport them to the liver where it's passed from the body. some experts even think that HDL's remove excess fat buildup from the walls of the arteries, thus the name, "good" cholesterol.
References :
my former bio teacher's lectures

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hope this helps!

By: nchantingprincess

nchantingprincess — Sat, 30 May 2009 20:12:59 +0000

Good cholestrol is what the body requires, bad cholestrol is a NO NO.
References :

By: Madcat

Madcat — Sat, 30 May 2009 19:37:59 +0000

Here is the American Heart Association's explation:

http://www.americanheart.org/presenter.jhtml?identifier=1516

and here is an interesting article by Dr. Ravnskov "The Cholestrol Myths":

http://www.ravnskov.nu/cholesterol.htm

I didn't read it all but sounds interesting

hope this helps
References :

By: cooldude

cooldude — Sat, 30 May 2009 19:32:59 +0000

What people refer to as good cholesterol and bad cholesterol are not really cholesterol at all. They are actually carrier proteins that act like "baskets" to transport cholesterol between the blood and the liver. The "bad" form is low-density lipoprotein, which carries cholesterol from the liver, where it is made, to the blood. It is considered bad because too much cholesterol in the blood slowly clogs arteries, eventually causing heart disease. On the other hand, what is termed "good" cholesterol is a high-density lipoprotein that transports cholesterol from the blood to the liver.

Your body makes c
holesterol because it is a building block for a number of essential substances. These include:
Pre-vitamin D, which is converted by sunlight to vitamin D
Testosterone, the "male" sex hormone
Estrogen, the "female" sex hormone
Progesterone, a sex hormone found in both males and females
Bile salts, that nasty yellow stuff that comes up with severe nausea
Other critical steroid hormones that help to regulate such important things as potassium and sodium levels
Excess cholesterol is "stored" in the blood. The actual cholesterol levels are determined by a number of factors, including heredity, diet and exercise. Diet appears to be the most important of these
References :
it seems you copy this question on this site, so I'll just copy the answer too. lol.

http://www.sciam.com/askexpert_question.cfm?articleID=0008710C-A768-1C71-9EB7809EC588F2D7&catID=3&topicID=12