Is 'good' cholesterol really that good for you? New research says maybe not

Cholesterol, a type of fat found in our blood, is needed to build healthy cells. [iStockphoto]

A recent study published in the Journal of the American College of Cardiology has discovered that HDL cholesterol, commonly known as the "good" cholesterol, may not always be good for heart health.

Cholesterol, a type of fat found in our blood, is needed to build healthy cells. However, high levels of cholesterol can increase the risk of getting heart disease.

HDL (High-Density Lipoprotein) is often called the "good" cholesterol because it helps remove other forms of cholesterol from the bloodstream compared to its counterpart LDL (Low-Density Lipoprotein), which is often called the "bad" cholesterol because it can build up in your arteries and form plaque which can lead to heart disease.

However, the study scrutinised the relationship between HDL cholesterol levels and heart disease in black and white participants. It found that high levels of HDL cholesterol were not associated with protection against heart disease in either group.

For low levels of HDL cholesterol, there was a link to a higher risk of heart disease in white participants but not in black participants.

This study is the first to find a difference in the risk tied to low levels of HDL cholesterol between black and white people. It also contributes to accumulating evidence that an elevated level of HDL cholesterol isn't necessarily helpful for one's heart health.

This means that having high levels of HDL cholesterol may not always protect against heart disease. It brings out that the relationship between HDL cholesterol and heart disease is more complicated than previously thought.

The study was conducted by reviewing data from 23,901 United States adults who participated in the Reasons for Geographic and Racial Difference in Stroke Study (REGARDS).

Study participants enrolled in REGARDS between 2003 and 2007. Researchers analysed information collected over 10 to 11 years.

Black and white study participants shared similar characteristics such as age, cholesterol levels and underlying risk factors for heart disease including having diabetes, high blood pressure or smoking.

This study may help inform future studies and interventions aimed at reducing heart disease risk, especially in diverse populations.

It brings out the unprecedentedly complex relationship between HDL cholesterol and heart disease risk. A relationship that was previously assumed to be straightforward.

Sources of HDL include olive oil, avocado, fatty fish and nuts while LDL foods include red meats, full-fat dairy products, fried foods, processed meats and bakery products.