Cholesterol is a crystalline substance that is really a steroid. However, because it is soluble in fats rather than water, it is also classified as a lipid, as fats are. It is found naturally in the brain, nerves, liver, blood, and bile of both humans and vertebrate animals. This is why people who want to decrease their cholesterol levels should consider cutting back on the Quarter Pounders with Cheese, along with other animal products.
The word has come to have evil overtones, but cholesterol is actually necessary for the proper functioning of the body. About 80% of total body cholesterol is manufactured in the liver, while 20% comes from what you eat. It is used by the cells to build membranes, and is also used in sex hormones and in the digestive process. Cholesterol travels from the liver through the bloodstream to the various tissues of the body by means of a special class of protein molecules called lipoproteins. The cells take what they need and any excess remains in the bloodstream waiting for other lipoproteins pick it up and take it back to the liver.
There are two main types of lipoproteins: HDLs (High density lipoproteins) and LDLs (Low density lipoproteins). The LDLs are considered to be "bad cholesterol" because this acronym looks a lot like LDS, and you know about them . . . No, seriously, they are chocked full of cholesterol, because they are the molecules which transport cholesterol from the liver to all the cells of the body. HDLs are called "good cholesterol" because they carry relatively little cholesterol and circulate in the bloodstream removing excess cholesterol from the blood and tissues.
After the HDLs travel through the bloodstream and collect excess cholesterol, they return it to the liver, where it is again incorporated into LDLs for delivery to the cells. If everything is working correctly, this system remains in balance. However, if there is too much cholesterol for the HDLs to pick up promptly, or if there are not enough HDLs to do the job, cholesterol can form a plaque that sticks to artery walls and may eventually cause heart disease. When you think of plaque and the way it forms, think of a getting to know you node and how it attracts so much potential garbage.
The normal HDL levels for men is 45-50 mm/dl, and for women is 50-60mg/dl. It is suggested that higher levels such as 70-80 mg/dl, may protect against heart disease. An HDL level under 35 mg/dl is considered risky. So if you have a cholesterol reading of 200, with HDL at 80 and LDL at 120, you are considered at low risk for heart disease. On the other hand, even if you have a total cholesterol level well under 200, if your HDL level is under 35, you would still be considered at increased risk of developing cardiovascular disease. In other words, as your HDL decreases, your potential for heart problems intensifies, even if your total is on the low side.
Now, who wants to go for some ribs?