Understanding high cholesterol

What is cholesterol?

Cholesterol is a fatty, waxy substance that is crucial to almost every cell in the body. We need it to make hormones and for brain function. However, too much of a certain type of cholesterol increases our risk of heart attack and stroke. For decades, total cholesterol was believed to be the enemy when it came to heart health, but the latest research suggests this is not the whole story.

If you have been told you have high cholesterol, you’re not alone. About 53% of UK adults have levels of total cholesterol above the recommended amounts.

Is there ‘bad' cholesterol?

Most of us know there's a link between cholesterol and heart health but not the difference between the so-called ‘good’ and ‘bad’ cholesterol. The body makes about 75% of our cholesterol in the liver, this is packaged together with other essential fats for delivery to our cells in transport vehicles called lipoproteins. What determines if cholesterol is ‘good’ or ‘bad’ isn’t the cholesterol, but the type of lipoprotein that transports it. There are two main classifications; low density lipoprotein (LDL) and high-density lipoprotein (HDL).

LDL moves cholesterol from the liver and carries it all over the body via the blood stream to where it may be needed, including your arteries. If there is too much LDL, these particles, especially if they are small, may become deposited in the arteries and cause plaque build-up, which is why LDL has a ‘bad’ reputation.

HDL particles do the reverse, they pick up excess cholesterol and transport it back to the liver, this is why HDL is often referred to as ‘good’. It is the levels of these different lipoproteins that matters – put simply, you want to keep LDL low and HDL high-ish.

What causes elevated LDL cholesterol?

There are numerous factors influencing your LDL cholesterol levels, these include:

• What you eat: an excess of foods rich in saturated fat, like processed meat, fast foods that may contain trans fats, and highly processed and refined carbs may increase LDL levels
• Your body weight: being overweight or obese, and having high levels of visceral or abdominal fat
• Smoking or vaping: these lower your HDL cholesterol, potentially making your balance of cholesterol less favourable
• Excess alcohol elevates cholesterol and other blood fats
• Medical conditions such as diabetes, chronic kidney disease and HIV
• Certain prescribed medication including some blood pressure pills and HIV medicines
• Age: as we get older our levels of LDL cholesterol rise
• Gender: women after menopause will experience an increase in LDL
• Genes: if your blood relatives have high cholesterol levels, you may too.

How to find out if you have high cholesterol

Your GP will check your cholesterol levels by using a simple blood test or ‘lipid profile’, this will measure your total cholesterol, HDL cholesterol, non-HDL cholesterol, LDL cholesterol and triglycerides (other fats). The test may involve either a blood draw from your arm or a simple finger prick test. You may be eligible for an NHS cholesterol test if you are over 40 and have not been tested before, are overweight, have a genetic predisposition to high cholesterol or a heart condition. For those over 40, a midlife health check, that includes a cholesterol review is available on the NHS every 5 years.

In the UK cholesterol is measured as millimoles per litre of blood (mmol/L) with current recommendations as follows:

• Total cholesterol should be below 5mmol/L
• HDL should be above 1.00mmol/L for men and above 1.2mmol/L for women
• Non-HDL should be below 4.00mmol/L (this is largely made up of LDL plus other less favourable forms of cholesterol)
• LDL should be below 3.00mmol/L

You may be told you have high cholesterol (hyperlipidemia) if there is too much total cholesterol in your blood. However, always ask your GP to explain the break down of your numbers as it’s possible to have a healthy total cholesterol but an unhealthy balance of the other types.

What are the risks of high cholesterol?

When determining your risk of heart attack and stroke, which remains the number one killer of women, high levels of LDL cholesterol are a key factor. However, while a test shows your cholesterol level at one point in time, if LDL levels remain elevated, combined with a number of other factors including high blood pressure, smoking or diabetes, you will still be at risk of heart disease or stroke.

What's more, it may not just be high levels that are a concern – fluctuating cholesterol and triglycerides levels during mid-life (after the age of 60) are associated with an increased risk of dementia and Alzheimer’s.

Ways to lower your cholesterol

Consider statins

The main treatment medication for high cholesterol are a group of drugs known as statins. These work by slowing the body’s production of cholesterol by binding to a specific enzyme in the liver (known as HMC-CoA reductase).

Your GP may decide this is an appropriate treatment for you if your risk of heart disease or stroke is high, you have a genetic condition that predisposes you to high cholesterol or you have already had a heart attack or stroke. As with all medication, some people may experience side effects which may include headaches, dizziness, muscle pains and fatigue, and more rarely kidney and liver problems. You should discuss your personal circumstances with your GP so you fully understand the risks and benefits of any chosen course of action.

Diet and lifestyle tips to reduce your cholesterol

We previously believed certain foods, like eggs, were to blame for high cholesterol. We now know this is incorrect – only 2% of the fat we eat will be in the form of cholesterol, so you’d need to eat a lot of these offending foods to put yourself at risk.

There are a number of dietary changes that can be effective and help you manage your cholesterol levels, these include:

• Cut down on saturated and trans fats (red meat, butter and tropical oils like coconut, as well as fast foods and take-aways)
• Eat fewer refined and processed foods like pastry, bread and biscuits, these can raise insulin levels and lead to the production of LDL cholesterol
• Focus on mono and poly-unsaturated fats such as those in oily fish, nuts and seeds as well as olive oil
• Increase the plant foods in your diet, such as beans and pulses, studies suggest a plant-focused diet improves LDL cholesterol levels
• Eat more foods rich in fibre, especially soluble forms of fibre such as that found in oats and flaxseeds – these help the body remove excess cholesterol
• Certain foods, like avocado, are rich in compounds called plant stanols and sterols, these foods help inhibit the absorption of cholesterol in the gut
• Eat a variety of fruit and vegetables – these may help protect LDL particles from the damaging effects of a natural process called oxidation, which may lead to plaque formation
• Try to be more active – this can be anything from a gentle walk to a more challenging run
• Stop smoking or vaping
• Be aware of your alcohol intake and keep within government guidelines
• Achieve and maintain a healthy weight for your height, age and gender.

Discover 10 ways to lower cholesterol.

So, is high cholesterol bad?

Cholesterol in itself is not inherently ‘bad,’ actually it's essential for life, but your own personal balance of cholesterol levels may be the issue. If you're told you have high cholesterol, it's important that you understand the breakdown of your cholesterol numbers and consider any other factors, including lifestyle choices and diet, that may put you at increased risk of a heart attack or stroke.

Enjoyed this? Now read

What is high blood pressure?
What is a low GI diet?
What is the DASH diet?
What is the Mediterranean diet so healthy?

Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food. Find her on Instagram at @kerry_torrens_nutrition_

All health content on bbcgoodfood.com 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 healthcare professional. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.