HDL cholesterol is often treated as good cholesterol but the truth is different.The mathematical value of hdl cholesterol does not justify the real benefits it provides.Complexities lie in this issue as the quantity or functionality of HDL cholesterol is important in judging the cardiovascular health benefits.
Now the issue raised about good cholesterol is either always good or sometimes it’s bad too.
1.Good HDL: The Health protection of HDL Cholesterol
HdL cholesterol is treated as good cholesterol because of the key protection it performs in the body.
1.Reverse Cholesterol transport: HdL takes the cholesterol from the wall of the arteries and recovers back to liver for excretion.This prevents the hardening of arteries and clears the cholesterol plaques.This process decreases atherosclerosis and risk of cardiovascular disease.
2.Antioxidant properties:Oxidised LDL Cholesterol is mainly deposited in the arteries and atheroma plaque formed.HdL prevents the oxidation of LdL cholesterol.
4.Endothelial protection:HdL produces nitric oxide and helps in relaxation of vessels and improves blood flow.
3.Anti-inflammatory effect:HdL has anti-inflammatory effects on the macrophages laden in the atherosclerotic plaques and reduces inflammation in the arteries.
Bad HDL :When we say HDL Cholesterol is bad for health?
There are certain times when HDL Cholesterol is less protective and bad , even harmful.
1.Dysfunctional HDL: In certain conditions Hdl particles lose their protective properties and become pro-inflammatory and induce oxidative stress. In chronic inflammatory diseases like Rheumatoid arthritis and Diabetes dysfunctional HDL particles lead to bad effects.
2.Extremely high HDL: When the HdL values are high above 100mg/dl leads to increased risk of atherosclerosis and cardiovascular disease.The reason for this is genetic factors and dysfunctional HDL.
3.Genetic disorders:
Familial hyper alphalipoproteinemia leads to high HDL levels.but this doesn’t confer any protection against cardiovascular disease.
It’s more complex than expected as the measured values of HdL don’t speak about their cardiovascular protection.
1.Quality over quantity:The positive effects of HDL depend more on functionality of HDL particles than only just quantity.
Assessment of HDL functionality is an important issue for their benefits. There are different investigations for assay of hdl functionality. They are described separately.
2.Impact of lifestyle and medication:
Adequate amount of exercise improves the functionality of HDL compared to rise in hdl levels.
Proper diet with low carbohydrates and low fat may have an impact on hdl levels and its functionality.
Certain lipid management drugs increase the values of hdl but it won’t confer expected cardiovascular health benefits.
3.Interaction with other lipoproteins:
HdL cholesterol exchanges the lipid particles with VLDL and LDL . These complex mechanisms lead to change in hdL functionality and risk of cardiovascular disease.
4.Individual variation:
Genetic factors , ethnicity and underlying diseases influence hdL values and functions.So everyone will not fit in one frame and benefit by the same size for the measured value of HDL.