Help me understand Cholesterol?

From what I know, we eat foods that contain cholesterol and other fats. Because cholesterol and fats are not water soluable, or dissolve in the blood stream, they need to be transported by lipoproteins to the liver for proper breakdown. The more cholesterol & fat you consume the more lipoproteins the body needs to create. Problem occurs when you consume a lot of cholesterol and fats and the body needs to create lots of lipoproteins (LDL) which then clog arteries. I guess the question arises, why is LDL bad and HDL good. Does it have to do with the density of LDL; maybe the LDL picks up cholesterol and because its low density lipoproteins it breaksdown before it gets to the liver?

Please correct me if anything I said was wrong. Thanks
Everyone is giving me different answers.

"Since cholesterol is insoluble in blood, it is transported in the circulatory system within lipoproteins" Just pulled that off of a website, and I watched a video that said the same exact thing. I guess where I made the mistake was that only HDL sends cholesterol to the liver.

No one answered my question though, I am asking WHY LDL tends to "narrow" arteries.

4 comments

  • lauryl4062

    LDLs is considered "bad" cholesterol because it delivers cholesterol/fats to peripheral tissues from the liver (and deposits them usually in fat cells, but possibly in other places like your arterial lining…) HDLs move the fatty acids/cholesterol from these deposits back to the liver so that they can be made into bile. So, LDLs put fat into your body, and HDL takes it out. Hence, "bad" and "good" cholesterol. Their names (low density lipoproteins and high density lipoproteins) come from what proportions of fat/cholesterol molecules they are carrying, but I don’t know what’s in what off the top of my head.

    By the way, when you absorb fats and cholesterol from your intestine, it first is in a lipoprotein called a "chylomicron." I’m sure you can find a very nice diagram about lipid metabolism and delivery if you google it.

  • John W

    Well most of blood are not water soluble, blood cells most certainly aren’t soluble. Solubility has nothing to do with the problem of cholesterols. There’s nothing about lipoproteins in terms of transporting cholesterol to the liver. LDL is a cholesterol so is HDL. Cholesterol is produced by animals and is an important part of many hormones such as testosterone, if we didn’t eat cholesterol, we would make what we needed. Problem is some cholesterols (the bad ones) tend to build up plaque in the blood vessel walls thereby making the passage narrower, others (the good ones) will actually remove plaque. This isn’t exactly like a pipe getting gunked up, more like the walls getting thicker.

    You should probably take a few biology courses before jumping into the fray.

  • Claudia

    http://en.wikipedia.org/wiki/Cholesterol

    To much to explain. Best explanation there is!

  • McGee

    There is no such thing as "bad" cholesterol – it’s all the same thing.

    When you don’t drink enough water, the blood becomes acidic. During its passage through the lungs, more water is lost through the process of respiration. When it reaches the arteries, this acidic blood is under a high shearing pressure that damages the lining with minute holes and abrasions.

    Left untreated, this damage could peel off and cause an embolism in the brain or other organ. To prevent this from happening, the so-called "bad" cholesterol is formed to cover and protect the damaged areas like a waterproof bandage until it can be repaired.

    The problem comes in when the medical community doesn’t understand the role of water in the body and the dehydration goes unchecked, allowing the damage to worsen until the buildup of cholesterol becomes a problem in itself.

    Water and salt are two of the three most vital substances the body needs to survive – without these, you would die. Yet, doctors have you stay away from salt claiming it causes high blood pressure (which it does not) and they also campaign to "drink plenty of fluids" when water substitutes such as soft drinks, coffee and others contain caffeine and other ingredients that are toxic to the body and cause dehydration.

    If the medical profession understood the role of water in the body (and the consequences of not drinking enough water) they would never sanction drinking anything but water.

    It should be noted that cholesterol is tested for by taking a blood sample from a vein in the arm. Yet, in all of medical history, there has never been a case where a vein has ever been blocked by cholesterol. Venous blood moves much slower than blood in the larger arteries. If the assumption of "bad" cholesterol is correct, the veins and smaller capillaries would become blocked long before the arteries.

    The fact that only the arteries are affected is because this is where the damage from acidic blood is happening, and so this is where the cholesterol is needed to prevent embolisms to the brain, saving your life. Although we get as much as 25% of our cholesterol from the food we eat, this doesn’t mean it automatically goes to the arteries. If it is not needed, it gets broken down and flushed out of the body just like excess salt and anything else.

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