All about cholesterol
What is cholesterol?
Why do we have cholesterol?
What is HDL?
How do we get rid of excess cholesterol?
What are triglycerides?
What is C-reactive protein?
What is homocystein?
What is cholesterol?
Cholesterol is a waxy kind of fat that is present throughout our bodies. It is manufactured by the body from fat in the diet. It is insoluble in water (and blood) so it is carried in the bloodstream by proteins called lipo-proteins (lipo = fat). The lipoprotein-cholesterol complex is soluble and allows for transport of cholesterol around the body.
Why do we have cholesterol if it is so dangerous to our arteries?
We need cholesterol!
Cholesterol is a vital ingredient in a variety of process in our bodies:
If we did not have cholesterol we would have no hormones and our brains would be a quart of mush.
- many of our hormones including our hormones are made from cholesterol including our sex hormones:
- our cell walls contain cholesterol as part of their structure:
- the scaffolding that holds or brain cells in place contains cholesterol as part of its structure. We should not say that someone is a "fat-head": we are all "wax-heads"!
What is HDL?
Cholesterol is a wax and does not dissolve in water. To circulate in the blood they need to be bound to a protein that make the combined molecule soluble.
Imagine that the cholesterol is being carried on a highway.
Some is in a big truck called HDL. The cholesterol is completely enclosed and cannot be grabbed by the cholesterol receptors in the arteries. None is off loaded to cause hardening of the arteries.
Some cholesterol is in a pick-up truck called LDL. It is partially exposed to the cholesterol receptors in the arteries and some is dropped off and causes hardening of the arteries, arteriosclerosis.
Some choleasterol is on a motorbike. It is totally exposed and can easily fall off causing arteriosclerosis.
HDL is GOOD, LDL and VLDL are BAD. Keep your cholesterol in big trucks!
How do we get rid of cholesterol?
Cholesterol is broken down (oxidized) in the liver. It is then dissolved in bile. The bile is collected in the gall bladder. (If it sits in the gall bladder too long some cholesterol salts out forming crystals which eventually grow into stones. Gallstones are cholesterol stones).
When we eat a fatty meal the stomach sends a message to the gall bladder to contract and squeeze out bile. The bile travels down the bile ducts to the small intestine just in time to meet the fatty meal. Bile breaks fat into tiny globules just the right size to be absorbed through the wall of the small intestine. Unfortunately some of the cholesterol is reabsorbed along with the fat in the fatty meal.
To get rid of cholesterol we need to stop the cholesterol from being reabsorbed. There are two ways to do this:
Method 1: keep cholesterol away from the bowel wall.
- keep the cholesterol away from the transport mechanism in the small bowel wall and
- block the transport mechanism.
Bile acid is a dye. If your pet ever had bilious vomitting on a rug you already know this from the difficulty of cleaning the rug. Bile stains fibre. If you can get the bile containing the cholesterol to stick to fibre it will stay away from the transport mechanism in the bowel wall and pass on through the bowels. Soluble fibre in the diet is effective in lowering cholesterol in this manner. Get more fibre!
Method 2. Block the transport mechanism.
Imagine that the trasport mechanism in the bowel wall is a subway train system. The fat gets on a train from a station on the bowel interior. It gets off at a station on the outer wall of the bowel where there are lots of blood vessels like taxis in a taxi ramp ready to carry it away to the rest of the body.
If you can fill up the train with other molecules, cholesterol cannot get on and passes on through the bowels. Plant sterols do this. Plant sterols are chemicals similar to cholesterol. They are contained in varying quantities in fruits, vegetables and nuts.
Not only do plant sterols get on the train faster than cholesterol, they refuse to get off! The metabolim and transport of plant sterols is slower than that of cholesterol. Once in the transport mechanism they stay there for longer than cholesterol does. Plant sterols effectively block the cholesterol transport mechanism. Do what Mother says, "Eat your veggies!"
What are tryglycerides?
Triglycerides are an oily knd of fat. They are made from the carbohydrate in the diet. Diabetics have high triglycerides when their sugar is high.
Triglycerides are dangerous because
How to reduce triglycerides.
- they irritate the arteries and allow cholesterol to be deposited.
- they can build up in the liver, causing "fatty liver". Fatty liver can interfere with cholesterol metabolism and make the person more vulnerable to arteriosclerosis.
You can reduce production of triglycerides by reducing the carbohydrates in the diet: e.g., bread, potatoes, pasta, sweets, sugars, desserts, alcohol.
You can burn triglycerides as muscle fuel during long, steady, aerobic exercise e.g., brisk walking.
Good control of diabetes or pre-diabetes will reduce triglycerides. Pre-diabetes is that stage when a person is developing diabetes but is not quite diabetic yet. Even if the sugar is close to normal the person may have high triglycerides. If your doctor notes that you have high triglycerides you may be sent for further diabets tests even if your fasting sugar seems normal.
is a protein that can be measured on blood testing. It is an index of inflammation in the body. It is particularly important in measuring the inflammatory processes in the arteries that leads to the deposition of cholesterol in the arteries.