For many people, the talk of cholesterol is confusing. We often hear about ‘good’ cholesterol and ‘bad’ cholesterol. We’re told to lower our cholesterol for cardiovascular health but many are unsure what that actually means and what it looks like in a diet. In this article, we’ll take an in-depth look at cholesterol and hopefully answer some frequently asked questions about this substance and our health.

What is cholesterol?

Before we begin talking about it, we need to know what cholesterol actually is. This substance is a fat-like, waxy material that can be found in every cell of the body. We need this substance to make certain things like vitamin D, hormones, and other things to help us digest our food. However, the human body is clever in that it already makes all of the cholesterol needed. Just like us, other animals have cholesterol and when we consume animal products like milk, cheese, eggs, and meat, we consume cholesterol. 

What happens if we have too much cholesterol in our blood?

Having too much cholesterol going around the bloodstream means that it will form plaque as it combines with other things in our blood. This plaque attaches itself to artery walls. The medical name for plaque build-up is atherosclerosis. When this is severe and the coronary arteries narrow or become blocked, causing coronary artery disease. 

What are the different types of cholesterol?

All types of cholesterol are lipoproteins. There are three types: LDL, HDL, and VLDL. They’re all a mixture of protein and fat (lipid). The fats move through the blood when they’re attached to proteins. The different lipoproteins have different functions. 

LDL cholesterol 

This means low-density lipoprotein. This is the cholesterol we hear referred to as “bad” as it causes plaque to build up in the arteries. 

HDL cholesterol

This means high-density lipoprotein. This is the cholesterol we hear referred to as “good”. HDL cholesterol carries cholesterol around your body to your liver, which then removes it from your system.

VLDL cholesterol

This means very low density lipoprotein. This also contributes to plaque build-up and so people call it “bad”. However, it is different from LDL in that it mainly transports triglycerides and not cholesterol like LDL.

What causes a person’s cholesterol level to be high?

The biggest single cause of high cholesterol is being unhealthy. This means:

  • Making poor food choices – e.g. eating too much saturated fat or trans fats. Foods containing saturated fat include baked goods, processed foods, deep-fried foods, chocolate, dairy products, and some meats. Trans fats are found in processed and fried foods. These fats raise LDL cholesterol.
  • Not enough physical activity – e.g. leading a sedentary lifestyle with not much exercise. This is known to lower your “good” HDL cholesterol.
  • Tobacco – this lowers “good” HDL cholesterol, particularly for women. It also causes the levels of “bad” LDL cholesterol to rise. 

Genes can also cause a person’s cholesterol to be high. The condition FH (familial hypercholesterolemia) is a form of inherited high cholesterol. 

How can cholesterol levels be lowered?

It’s possible to reduce cholesterol levels by making healthy changes to your lifestyle. This includes eating healthily, managing weight, and doing regular exercise or physical activity. There are also medicines available if lifestyle changes don’t work on their own. Statins are drugs that lower cholesterol. They work by blocking the enzyme that helps the liver to produce cholesterol. They also activate the LDL receptors in the liver cells so that the blood ‘captures’ more cholesterol.

What is the link between high cholesterol and cardiovascular disease?

The relationship between cardiovascular disease and cholesterol is complex. A 2017 study that appeared in the Journal of the American Heart Association, discovered that lots of people who suffer from a heart attack don’t actually have high cholesterol. These findings meant that many experts began to question the link between high cholesterol and cardiovascular disease. Similarly, a 2005 studies review in the American Journal of Clinical Nutrition discovered that there was no strong link between cardiovascular disease and the intake of dietary cholesterol.

Conversely, research published in The Lancet in 2019 discovered a rigorous link between the long-term risk of cardiovascular disease and non-HDL cholesterol.

Whatever the reality, leading a healthy lifestyle by exercising regularly, eating well, maintaining low blood pressure, and refraining from smoking is the best thing you can do for cholesterol levels and heart health.