Cholesterol is an important fatty substance, or lipid, that is essential for our body to function. The liver typically creates it, but it can also be found in a number of foods. To reduce cholesterol levels, a diet low in saturated fat is typically advised.
Consuming cholesterol itself has little impact on the level of cholesterol in the blood. But before drastically changing your diet, you should always contact your GP first.
Cholesterol is insoluble in water; therefore it is carried throughout the body by attaching itself to proteins. When the proteins and cholesterol combine, they are called lipoproteins. There are two relevant types of lipoproteins: LDL-cholesterol (the bad type) and HDL-cholesterol (the good type).
If you have extremely high total and LDL cholesterol levels, it can negatively impact your health - especially when combined with smoking and a high blood pressure. You may not even know you have high cholesterol as it doesn’t cause any symptoms on its own. It can however, increase the risk of developing heart disease.
On this page we will find out what high cholesterol is, the types and risks of having high cholesterol and if certain groups of people are at a greater risk from high cholesterol. We will also discover how high cholesterol can be prevented, what foods to choose for a low cholesterol diet and how a nutrition professional can help you achieve a lower cholesterol.
What is high cholesterol?
Although cholesterol is essential for good health, having high cholesterol levels may increase your risk of cardiovascular diseases such as stroke and heart disease. As mentioned above, the odds of you noticing that you have high cholesterol are slim. This is mainly because high cholesterol itself does not cause any symptoms.
Having increased cholesterol levels, however, can cause fatty deposits - that are also known as plaques - to build up inside your arteries. Over a period of time this can this can narrow your arteries, restricting the blood flow to your heart and other important organs. This can potentially cause a pain in your chest (angina).
If one of the plaques inside your arteries bursts, it can cause a blood clot which can cut off the blood supply to your heart. This can then cause a heart attack. Or if it cuts off the blood supply to your brain, it could cause a stroke.
Types of cholesterol
The different types of lipoprotein include:
High-density lipoprotein (HDL)
High-density lipoprotein is typically referred to as the ‘good’ type of cholesterol. This is because it helps remove excess cholesterol from your blood vessels. It manages to do this by transporting cholesterol to your liver from your tissues. Your liver then takes the cholesterol and breaks it down, which enables it to be removed from your body. HDL aids with the prevention of cholesterol build-up in your blood vessels, helping reduce the risk of stroke and heart disease.
Low-density lipoprotein (LDL)
Low-density lipoprotein transports cholesterol around your body from your liver to whatever needs it. But if your LDL levels are too high, it can produce fatty deposits in your arteries. This can increase the risk of stroke and heart disease. This is why LDL is often referred to as ‘bad’ cholesterol.
Cholesterol is not the only lipid (fat) to pose a risk to the vital organs. Doctors also test for:
Whereas cholesterol builds and maintains cell membranes and creates hormones, triglycerides maintain the transportation and storage of energy. Like cholesterol levels, avoiding certain fatty foods can lower triglyceride levels.
What are the risks?
An individual with high cholesterol is more likely to develop serious conditions such as coronary heart disease, stroke and TIA (a mini-stroke).
Coronary heart disease
If the blood supply contains a high amount of cholesterol, there is a greater risk of fatty deposits breaking off and sticking to arterial walls. This accumulation causes a narrowing of the passage known as ‘atherosclerosis’, which restricts the blood flow to the heart. The arterial walls, now sticky and rough with the build-up of fatty deposits (referred to as plaque), can cause clotting of the blood. This can in turn cause a heart attack.
Like a heart attack, a stroke can be caused by a blood clot or an accumulation of fatty deposits caused by high cholesterol. This blockage can restrict or entirely block the blood flow to the brain, leading to a stroke. Symptoms of a stroke include facial droopiness, limb paralysis, slurred speech and confusion.
A transient ischaemic attack, otherwise known as a mini-stroke, is similarly caused by a slight restriction of blood to the brain. With a TIA, symptoms drastically reduce within the first 24 hours.
Who is at risk?
There are a number of reasons why certain people are more likely to suffer from high cholesterol levels than others.
Overweight or obese people
Daily dietary habit has been found to play a large role in determining cholesterol levels. A number of scientific studies have suggested a strong link between high-fat diets, high cholesterol levels and heart disease. Obesity, and particularly central obesity (carrying excess weight around the waist), which may be indicative of physical inactivity, is particularly significant. An excess of fat puts increased strain on the internal organs and heightens risks of high blood pressure, high cholesterol, heart disease and a wealth of other related problems. The good news is that following a number of simple lifestyle changes can reduce these risks. A modest sustained weight loss of 5-10% of body weight can improve lipid profiles.
Many factors cannot be changed. For example, individuals over the age of 40 are thought to more likely to suffer from high cholesterol.
Individuals of Indian, Pakistani, Sri Lankan or Bangladeshi descent have been found to be at a higher risk of high cholesterol than other ethnic groups.
A small percentage of individuals will have inherited metabolic defects such as ‘familial hypercholesterolemia’, which can increase the risk of high cholesterol. People who suffer from hypercholesterolemia often lack LDL-absorbing receptors found on the surface of liver cells. This can result in a build-up of LDL cholesterol leading to an increased danger of heart disease.
In very rare cases a child may have inherited the disorder from both parents. In this case, individuals often develop heart disease at a young age and may require repeat organ transplants throughout their life, regardless of lifestyle habits.
Individuals diagnosed with extremely high cholesterol levels (over 300mg/dl) are advised to encourage other family members to undergo testing as a precaution.
How can high cholesterol be prevented?
There are a number of simple lifestyle choices that can help lower cholesterol. Some ideas can be found below:
Exercising on a regular basis can help lower your cholesterol levels regardless of a change in weight. Example activities can range from cycling and walking to running and participating in team sports such as football and netball.
In many cases, around 150 minutes of moderate exercise (when you work hard enough to break a sweat and raise your heart rate) every week has been proven to improve cholesterol.
If you aren’t sure that you are doing moderate exercise, try talking and singing when you are taking part - you should be able to talk, but not able to sing a song.
If you smoke, quitting smoking can help improve your HDL cholesterol levels. Not only that, if you stop smoking your blood pressure, risk of heart attack and heart disease will decrease too.
Once you are found to have high cholesterol, your GP may prescribe you statins to help lower the cholesterol level in your bloodstream.
Statins help by reducing the amount of cholesterol produced by the liver. There are a number of different statin types and brand names.
The risks involved when taking statins have been widely debated. In some cases, statins have been proven to have adverse side effects such as liver and kidney problems. Consult your GP for further information.
A low cholesterol diet
To lower cholesterol, sticking to a balanced diet can help. For a low cholesterol diet tailored for you, a nutrition professional will be able to help.
Replacing foods that are high in saturated fat with those that contain unsaturated fats can help lower cholesterol. Typically in the UK, most people consume too much-saturated fat, with the highest proportion in the UK coming from meat and meat products.
Foods that contain unsaturated fats (the good fats) include:
- oily fish (e.g. mackerel and salmon) – one portion is a similar size to a pack of cards
- nuts (cashews, almonds) – one portion amounts to around 30g
- vegetable oils (olive, walnut, sesame seed, sunflower) – one portion amount to around 1tsp
- seeds (pumpkin and sunflower) – one portion amounts to around 30g.
Like unsaturated fats, trans fats can also raise cholesterol levels. They can naturally be found in small amounts in foods such as dairy and meat.
Artificial trans fats are typically found in processed foods that contain hydrogenated fats such as cakes and biscuits.
For your low cholesterol diet, aim to cut down on foods that contain trans fats or saturated fats and replace them with other foods that contain unsaturated fats.
Food prep - Reduce the fat
When choosing, preparing and cooking food, you should always try to reduce the total amount of fat you consume.
Go for lean cuts of meat and low fat spread and dairy products, or simply limit the amount of full-fat products you eat.
When cooking your food, instead of frying or roasting, try:
High-fibre foods can help reduce the amount of cholesterol in the bloodstream and can help reduce the risk of heart disease. In particular, soluble fibre has been shown to reduce total and LDL cholesterol. Foods that are high in fibre include:
- fruit and vegetables.
Tips for choosing good food
- Making a small change such as replacing a packet of crisps with a handful of cashews could help lower your risk of high cholesterol.
- Beans, peas and lentils are extremely filling and as part of a delicious recipe. These could act as a good substitute for fatty cuts of meat.
Cholesterol food myths
You may have heard that eggs, prawns, kidneys and livers are all naturally rich in cholesterol. Although we do get cholesterol from such foods, because they are low in saturated fat we don’t need to limit them as such compared with foods like cakes and biscuits. If you are unsure what foods you should stick to in your diet, a nutrition professional will be able to assist you.
How can a nutrition professional help?
Research strongly suggests that diet is an important factor when it comes to high cholesterol and resulting heart disease.
So why see a nutrition professional? Quite simply, a qualified nutrition professional knows what’s good to eat and what’s not. They can offer you their expert guidance without the confusion of conflicting theories or commercial dieting fads.
Everybody’s relationship with food is different. A nutrition professional will tailor a nutrition plan to your personal needs and requirements.
A nutrition professional may be able to encourage you to eat a healthy, low cholesterol diet, which could, in turn, help you lose weight, lower your cholesterol, reduce your risk of heart disease or experiencing a stroke or heart attack, and maybe even improve your enjoyment of life.
Content reviewed by dietitian, Katherine Kimber. All content displayed on Nutritionist Resource is provided for general information purposes only, and should not be treated as a substitute for advice given by your GP or any other healthcare professional.