Heart disease, high blood pressure, and cancer are just two of the many health problems associated with high levels of LDL, or ‘bad cholesterol’.
Many people are prescribed statins to reduce their cholesterol.
However, for those who don’t respond to statins, the idea of taking measures to raise HDL, ‘good cholesterol’ has often been explored.
Cholesterol is waxy substance produced mainly in the liver, although most body cells can make it when necessary.
It is vital for health as it is used to make hormones, vitamin D, bile acids and cell membranes but there are two main types of cholesterol – good HDL cholesterol and bad LDL cholesterol.
Good HDL-cholesterol removes LDL-cholesterol from the circulation and transports it back to the liver for processing.
But bad cholesterol has been linked with an increased risk of cardiovascular disease such as heart attack and stroke.
However, according to a study published in the American College of Cardiology, high levels of good cholesterol are simply not enough to keep people from an early grave.
Data from 631,000 individuals from the CANHEART cohort, a research database based in Canada, was closely analysed by researchers.
The data was divided into groups based on HDL levels, so scientists could examine the relationship between good cholesterol and mortality.
Experts found the people from poorer backgrounds and who had less healthy lifestyles, were more likely to have lower levels of HDL.
However, even when adjusting for lifestyle factors, lower HDL levels were still associated with an increased risk of death from heart attack and a non-heart attack death, such as cancer.
Professor Dennis Ko, from the Institute for Clinical Evaluative Sciences in Toronto, and author of the study, said: “The link between good cholesterol and heart disease is complex, but it seems certain that there is a connection between people with low good cholesterol levels and other well-known risk factors for heart disease such as poor diet and exercise habits and other medical conditions.
“Focusing on raising HDL is likely not going to help these patients, but these findings show that one of the best interventions in treating and preventing heart disease continues to be lifestyle changes.”
But those with very high HDL levels had an increased risk of a non-cardiovascular related death.
The study is the first of its kind to show a link between HDL, cancer death and other causes of death.
The team are unsure as to why high levels of HDL increased levels of non-cardiovascular related death, but other research suggests this could be related to high alcohol intake.
The research casts doubt on HDL being used as an independent risk factor for heart disease or for raising good cholesterol levels to be used by itself as an intervention to reduce the risk of dying from heart disease.