High cholesterol levels are a significant risk factor for heart disease. And coronary heart disease takes the lives of more Americans than any other single cause. Of course, almost all adults are aware of this – but what exactly is cholesterol and why can it be harmful?
What is Cholesterol?
Cholesterol is a combination of steroids, alcohol and a lipid. It is a fatty like substance, and is a normal feature in the human body, found in the bloodstream and the cells, with the highest concentrations being in the brain, liver and spinal cord.
Cholesterol is both self-produced within the body and ingested through foods from animal and dairy products. These include butter, eggs, cheese, milk, meat, fish and poultry.
While food products obtained from plants don’t themselves contain much, if any, cholesterol, they may contain saturated as well as trans fats – and these induce the body to manufacture its own cholesterol.
Actually, the majority of our bodily cholesterol does not come from the foods we eat but is produced internally.
Cholesterol contributes to a number of important bodily functions, including:
- helps in the production of the membranes for all of our cells
- aids in the creation of bile, which is used to digest fat
- metabolizes vitamins A, D, E and K
- synthesizes some of the steroid hormones, such as those in the adrenal glands, as well as sex hormones
- some recent research indicates cholesterol may also act as an antioxidant.
How Can Cholesterol be Harmful?
Cholesterol is present in our bloodstreams in packages or carriers known as ‘lipoproteins’. These packages are necessary because cholesterol cannot dissolve in the blood.
There are two different types of cholesterol packages, these being low-density lipoprotein (“LDL”), which carries cholesterol throughout our body, and high-density lipoprotein (“HDL”), which removes cholesterol from our blood.
LDL is commonly referred to as the ‘bad’ cholesterol, and HDL, the ‘good’ cholesterol.
When the blood contains an excessive amount of LDL packages, over time they can build up on the walls of arteries that feed the brain and the heart, creating a hard, dense deposit of plaque that clogs the arteries (atherosclerosis) and eventually cause a stroke or a heart attack.
Conversely, HDL packages – the good cholesterol – are thought to transport excess cholesterol from the arteries to the liver where they are processed for expulsion from the body. This is believed to slow the build up of cholesterol in the arteries and thus reduce the risk of heart attack and stroke.
What is High Cholesterol?
As a rule of thumb, you should make sure your cholesterol levels are measured every 5 years (more often if you are a male over 45 years of age, or a female over the age of 55) to ensure you do not have high cholesterol levels.
Physicians measure a number of different levels of our cholesterol. We’ll now discuss the various measurements they take and what they may mean.
1. Total blood cholesterol level: This is the most common measurement of cholesterol and is measured in mg/dL (milligrams per deciliter of blood). Unless you have some other risk factors, total blood cholesterol is generally thought to be acceptable if it measures less than 200 mg/dL.
The middle level, which is associated with borderline high risk, is comprised of levels in the 200 to 239 mg/dL range. You should see that both your total cholesterol and HDL levels are tested every year or two if your total cholesterol is in this range and you do not suffer from any other heart disease symptoms. Also, you should watch your diet, and try to decrease the amount of foods you eat that are high in cholesterol and saturated fat. Consult with your physician and try to get down below the 200 mg/dL level.
You are said to have a high cholesterol level if it exceeds 240 mg/dL. And your risk of stroke or heart attack is double that of someone whose level is below 200 mg/dL. You must definitely seek medical advice to attempt to reduce your total cholesterol to a more acceptable level.
2. LDL cholesterol level
An LDL cholesterol level (the ‘bad’ cholesterol) that is too high may significantly affect your risk of stroke and heart attack. Generally speaking, the lower the level of your LDL cholesterol, the less you are at risk. You want a level below 130mg/dL. Between 130 and 160 is borderline risky. From 160 to 190 is high risk and above 190 mg/dL is very high risk.
3. HDL cholesterol level
For males, HDL cholesterol levels usually are in the 40 to 50 mg/dL range. For females, the typical range is between 50 and 60 mg/dL.
Low HDL cholesterol (under 40) can increase your risk of heart disease. These low readings are often caused by smoking or by not partaking of regular physical activity or being overweight.
4. Ratios
The ratio of total cholesterol level to HDL level should be below 5. If your total cholesterol level is 230 and your HDL level is 50, your ratio would be 4.6 (i.e. 230 divided by 50).
5. Triglyceride level
Your doctor will often also measure your triglyceride level. Here, a normal level is below 150 mg/dL; borderline is from 150 to 200; high risk is from 200 to 500; and very high risk is above 500 mg/dL.
A high reading may be indicative of an underlying disease or other problem. Lifestyle changes may be necessary to reduce your triglyceride. A reduction in carbohydrates may also be appropriate, as carbos tend to increase triglycerides and reduce HDL cholesterol.
In a subsequent article we’ll have a discussion on reducing cholesterol.
In the meantime, for more information on high cholesterol, you can review the following:
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