What’s so bad about bad cholesterol?
Is cholesterol bad in itself? No, it’s not, not at all.
So, what is cholesterol?
Cholesterol is an essential organic compound needed to make all steroid hormones. Our body can get cholesterol from food or make it from scratch in liver. Cholesterol does not mix with blood because it belongs to a class of fat-like substances called lipids. As you know, fat does not dissolve in water.
To transport cholesterol in our blood, they have to be packaged with special proteins called Apo-proteins. The package of cholesterol, fats and Apo-proteins are called Lipo-proteins. There are different types of packages that carry cholesterol in blood. The same cholesterol can be good or bad depending on what type of package it is carried in.
The particular package of Lipo-protein called Low Density Lipoprotein or LDL is the main cholesterol supplier. It takes cholesterol out of the liver to supply it to organs that need it. LDL is considered the bad cholesterol because it promotes deposition of cholesterol in organs, particularly arteries.
Bad cholesterol or LDL is bad because of how it is packaged and transported. The problem is the faulty transportation system that takes cholesterol where it is not needed. However, the organs that need cholesterol would not get it if LDL did not exist.
What’s so good about good cholesterol?
Just like bad cholesterol, good cholesterol is not actual cholesterol. It is also the package containing cholesterol, fats and Apo-proteins. Good cholesterol is also a type of Lipo-protein. This particular type of cholesterol package is called high density Lipo-protein or HDL.
HDL is the good cholesterol because it is the main scavenger of cholesterol. This particular type of package of Lipo-protein is made to collect excess cholesterol from all over the body and bring them back to your liver. Since HDL promotes removal of cholesterol from organs, they also help protect arteries from getting cholesterol deposits.
Good cholesterol package is good because of how it is transported and packaged. The actual cholesterol inside the HDL package is the same cholesterol that was initially inside the LDL package.
How is your good and bad cholesterol levels measured and reported?
When you get your cholesterol checked, the actual test that is ordered is fasting lipid profile. Lipids are fat like substances. Cholesterol is a type of lipid. Your lipid profile report includes the following items:
- Total Cholesterol
- HDL Cholesterol
- LDL cholesterol
Total cholesterol includes all types of cholesterol present in all packages. It is measured directly in lab. HDL cholesterol is the amount of cholesterol packaged inside the HDL Lipo-protein. Triglycerides are not cholesterol, they are simply fats similar to butter and oil. Triglycerides are measures along with cholesterol because they are also packaged inside similar Lipo-protein packages.
Triglycerides and HDL are commonly measured directly in most labs. LDL or bad cholesterol level is usually calculated by using a formula.
LDL = Total cholesterol minus (HDL + triglyceride/5)
This formula only holds true if the triglyceride level is less than 400. If it is higher than that, LDL or bad cholesterol has to be measured directly in special labs.
Bad cholesterol or LDL level
Among the numbers you get reported in your lipid profile, the number associated with your bad cholesterol or LDL level is one of the most important ones. The recommendation about what the ideal cholesterol number should be has changed many times since they were first measured. The latest set of recommendation is based on the 2013 guidelines published jointly by the American College of Cardiology and American Heart Association.
According to the new guidelines, there is no universal normal or ideal level of LDL that applies to everyone. The decision to treat your bad cholesterol with cholesterol lowering medication depends not only on your bad cholesterol level but also on your overall risks of heart attack. The only kind of blood cholesterol lowering medication that has been proven to lower your risk of heart attack is the kind called statin. Two things are used to decide whether you need stain:
- Your risk profile
- Your bad cholesterol level
If you have a history of heart attack or stroke, you have the highest risk. They recommend you take your statin regardless of your bad cholesterol level.
If your bad cholesterol level is 190 or higher, you need to take statin regardless of your heart attack risk. Bad cholesterol level higher than 190, in itself, is a major risk factor for heart attack.
If your bad cholesterol level is less than 70, you do not need statin unless you have a history of heart attack or stroke.
When your bad cholesterol level is between 70 and 189, you need to look at your heart attack risks before you decide about statin treatment. If you have diabetes and you are above 40 years old, your risk is already high enough to warrant statin treatment at this LDL level. Otherwise, you need to calculate your risk of heart attack.
You can calculate the risk percentage by using this calculator provided by American College of Cardiology. If your number comes out to be higher than 7.5%, you need statin treatment if you are between 40 and 75 years of age. If you do not meet any of these conditions, the decision to start statin should be based on individual risk-benefit discussion with your doctor.
What to do with your HDL or good cholesterol level?
Your HDL or good cholesterol level plays an important role in calculating your heart attack risks. The calculator provided by American College of Cardiology needs your HDL number to calculate your heart attack risk percentage. If your LDL or bad cholesterol level is in between 70 and 189, you need this number to make decision about taking statin. Low HDL levels increase your risks and high HDL levels decrease your risk.
In the past, HDL or good cholesterol level was individually evaluated and treated with medications that raised HDL level. However, recent research did not show any significant benefit in reducing heart attacks using that approach. Currently, HDL level is mostly used in deciding the need for statin treatment. Lowering LDL with stain is more beneficial in reducing heart attacks than raising HDL even in patients with abnormally low HDL levels.
What do you do with the total cholesterol level?
There is no real significance in knowing your total cholesterol level. However, some people still remember this number and use old reference numbers to see if their cholesterol is high, normal or low. This is wrong. Please forget your total cholesterol level, it is irrelevant. It is only used by your lab in the cholesterol formula to calculate your LDL or bad cholesterol level. That is the only place where total cholesterol level is useful.
What do you do with your triglyceride level?
Triglycerides are not cholesterol. If you want to learn more about them, you can read this separate detailed article on triglycerides.