We often hear warnings about cholesterol. However, your body actually needs some cholesterol to stay healthy. This article explains the different types of cholesterol and what you can do to keep your cholesterol levels healthy.
What is Cholesterol?
Cholesterol is a type of fat. It’s found in all the cells in your body and forms part of their outer layer. Cholesterol is also an essential part of many important hormones including oestrogen, progesterone and testosterone.
There are two main types of cholesterol:
- Low-density lipoprotein (LDL) cholesterol. This is also known as ‘bad’ cholesterol. High levels of LDL cholesterol can lead to atherosclerosis – a process in which fatty deposits build up on the walls of your arteries. This can reduce or block the blood flow in your arteries, leading to heart disease and stroke.
- High-density lipoprotein (HDL) cholesterol. This is also known as ‘good’ cholesterol. It carries excess cholesterol out of your blood to your liver, where it’s processed and removed from your body.
Your risk of heart disease and stroke is particularly high if you have high levels of LDL cholesterol and low levels of HDL cholesterol.
Sources of Cholesterol
There are two different sources of cholesterol – some comes from the food you eat, but most of it is made within your body.
Cholesterol that comes from the food you eat is called dietary cholesterol. Not many foods actually contain cholesterol. Examples of some that do are:
- Eggs
- Liver
- Kidney
- Prawns
Eating foods that are high in cholesterol won’t usually raise your blood cholesterol level much. Most cholesterol is made within your body, in your liver. Your liver can produce all of the cholesterol your body needs so dietary cholesterol isn’t an essential part of your diet. Your cholesterol levels are mainly influenced by the other fats that you eat.
Saturated Fats
The saturated fats you eat have the biggest impact on cholesterol levels in your body. Saturated fats cause levels of LDL cholesterol to rise in your blood, in proportion to HDL cholesterol. This raises your risk of heart disease and stroke. It’s important to limit the amount of saturated fats you eat. Saturated fats are found in foods such as meat, cheese, butter, cream and pastries.
Unsaturated Fats
Unsaturated fats actually reduce levels of LDL cholesterol in your blood. For this reason they can be a healthy choice, and it’s a good idea to replace saturated fats in your diet with unsaturated fats. Unsaturated fats are found in vegetable oils, sunflower spreads, nuts and avocados.
Trans Fats
Trans fats are artificially solidified vegetable oils. Similar to saturated fats, trans fats raise levels of LDL cholesterol, so try to save foods containing these fats for an occasional treat. Trans fats are found in many types of processed foods, including, biscuits, cakes and pastries.
Your Cholesterol Level
Your cholesterol level can be measured with a simple blood test. You can have a cholesterol test done at your GP surgery.
However, it’s important to remember that as well as your cholesterol level, other factors such as smoking and high blood pressure increase your risk of heart disease and stroke.
If you have high cholesterol, you can lower it by changing your diet and maintaining a healthy weight. Your diet should be low in fat overall and particularly low in saturated fats. It’s also important to eat plenty of fibre, especially soluble fibre, which is thought to lower cholesterol levels. Soluble fibre is found in fruits and vegetables, beans and oats.
If you’re overweight, losing excess weight may help to reduce your LDL cholesterol levels and increase your HDL levels. Increasing your physical activity levels may also help to raise your HDL levels.
If you already have heart disease or are at a high risk of getting it, your GP may prescribe cholesterol-lowering medicines, such as statins or fibrates.
There are some specially designed food products (for example, some spreads and yogurts) that are aimed at people who need to lower their cholesterol levels. These foods contain added ingredients such as substances produced by plants called sterols and stanols, which may help lower your blood cholesterol levels. If you choose to use these products, always read the label and make sure that you don’t eat too much. If you don’t have high cholesterol levels, you shouldn’t eat these products too often, particularly if you’re pregnant or breastfeeding.
Further information
• British Heart Foundation – www.bhf.org.uk
Sources
- Laker M. Understanding cholesterol. Poole: Family Doctor Publications in association with the British Medical Association, 2003:14–15
- Cholesterol. British Heart Foundation. www.bhf.org.uk, published August 2010
- Atherosclerosis. Merck online medical library. www.merck.com/mmhe, published January 2008
- Cholesterol. Food Standards Agency. www.eatwell.gov.uk, accessed 11 May 2010
Published by Bupa’s Health Information Team, December 2010.
Disclaimer
All content on this website is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. Always consult your own GP if you’re in any way concerned about your health.