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Control Your Cholesterol

What is Cholesterol?
Cholesterol is a wax-like, fatty substance, sometimes called a blood fat, because it circulates in our blood. It’s an essential part of every cell in our body and has many important functions. For example, it’s used as a building block to make hormones such as cortisol, testosterone and progesterone. It’s used to make bile acids, which help to digest fat. And it’s a component of vitamin D. If too much cholesterol circulates in the blood, it can affect the risk of coronary heart disease. A small amount of cholesterol comes from the foods we eat. However, most of the cholesterol in our body is made by the liver. The liver controls the amount of cholesterol that circulates in our blood and is responsible for distributing it to the areas in our bodies that need it.[1]

Technical Explanation[2]
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid),[3] a type of lipid.[4] Cholesterol is biosynthesised[5] by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid.

Cholesterol also serves as a precursor for the biosynthesis of steroid hormonesbile acid[6], and vitamin D. Cholesterol is the principal sterol synthesised by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), but there are some exceptions, such as Mycoplasma, which requires cholesterol for growth.[7]

Control Your Cholesterol
Picture Credit: “Control Your Cholesterol” by juhansonin is licensed under CC BY 2.0.

Every cell in the body needs cholesterol, which helps the cell membranes form the layers. These layers protect the cell’s contents by acting as the gatekeeper to what things can enter or leave the cell.[8] The body needs cholesterol to make Vitamin D and several hormones that support bones, teeth, and muscles[9].

François Poulletier de la Salle first identified cholesterol in solid form in gallstones in 1769, but it was not until 1815 that chemist Michel Eugène Chevreul named the compound “cholesterine”.[10]

Good and Bad Cholesterol[11]
A cholesterol test will measure:

  • total cholesterol – the overall amount of cholesterol in your blood, including both “good” and “bad” cholesterol
  • total cholesterol to HDL cholesterol ratio (TC: HDL) – the level of good cholesterol in your blood compared to your overall cholesterol level
  • good cholesterol (called HDL) – this makes you less likely to have heart problems or a stroke
  • bad cholesterol (called LDL and non-HDL) – this makes you more likely to have heart problems or a stroke
  • triglycerides – a fatty substance similar to bad cholesterol

You may just be told your total cholesterol when you get your result. You might be able to get separate results for your good and bad cholesterol, triglycerides, and your total cholesterol to HDL ratio. There’s a good article about cholesterol ratios and measurement at: If in doubt, ask your GP or nurse.

Why is LDL bad for you?[12]
LDL can build up on the walls of your arteries and make them narrower. The fatty deposits form plaque that lines your arteries and may cause blockages. This build-up is called atherosclerosis. Arteries are the blood vessels that carry oxygen-rich blood away from your heart to all other organs in the body.

What should your cholesterol levels be?
The following is just a guide. The levels you should aim for might be different. Ask your doctor or nurse what your levels should be.

High-density lipoprotein (HDL) is one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules around the body within the water outside cells.

Treating High Cholesterol[13]
Statins are the most common medicine for high cholesterol. They reduce the amount of cholesterol your body makes. Statins are a group of medicines that can help lower the level of low-density lipoprotein (LDL) cholesterol in your blood. LDL cholesterol is often referred to as “bad cholesterol“, and statins reduce the production of it inside your liver. You take a statin tablet once a day and usually need to take them for life.

You might need medicine to lower your cholesterol if:

  • your cholesterol level has not gone down after changing your diet and lifestyle;
  • you’re at a high risk of having a heart attack or stroke.

Other medicines may be used if statins do not work or you do not want to take statins for high cholesterol:

  • other tablets – such as ezetimibe, fibrates, bile acid sequestrants (also called resins) and bempedoic acid;
  • injections – such as alirocumab, evolocumab and inclisiran.

Stopping smoking and managing high blood pressure are also important for heart health. Good evidence shows that improving your blood cholesterol level can reduce your risk of cardiovascular diseases (heart attacks, strokes and angina).

There are many ways to lower cholesterol, such as[14]:

Can Cholesterol levels get too low?[15]
No, it’s impossible for cholesterol levels to get too low. You may have low cholesterol levels, but your body is still making it. The British Heart Foundation says you’ll never “run out” of it. The aim is always to balance your healthy (HDL) and unhealthy (non-HDL) cholesterol. If you stop taking statins when your cholesterol is at a normal level, your cholesterol could then rise to unhealthy levels again.

Cholesterol and the Facts about Fats[16]

Consume fewer saturated fats
Saturated fats generally stay solid at room temperature, whereas unsaturated fats are usually liquid. Food sources of saturated fats include:

  • red meat
  • pork
  • chicken (with the skin on)
  • butter
  • cheese and other dairy products
  • cooking oils, such as palm oil and coconut oil

The AHA recommend that saturated fat should only represent about 5–6% of a person’s daily calorie intake.

A diet high in saturated fats may raise a person’s LDL cholesterol levels. Excess LDL cholesterol can accumulate and form hard deposits in the arteries, which may lead to a condition called atherosclerosis.

2018 study examined how different dietary fats affected blood levels of cholesterol. The 4-week study involved 96 healthy adults who consumed 50 grams (g) daily of either:

  • extra virgin coconut oil
  • butter
  • extra virgin olive oil

Coconut oil and butter contain saturated fat, whereas olive oil contains mostly monounsaturated fat. According to the results of the 2018 study, the participants who consumed butter had significantly higher levels of LDL cholesterol than those in the coconut oil and olive oil groups. The study also showed that different types of saturated fat can vary in their effects on cholesterol levels.

For example, coconut oil significantly increased the participants’ levels of HDL cholesterol, whereas butter significantly raised LDL cholesterol levels. However, a 2015 systematic review did not find a direct association between saturated fat intake and risk of death, coronary heart disease, cardiovascular disease, stroke, or type 2 diabetes.

Consume more monounsaturated fats
Vegetables, nuts, and fish are rich in monounsaturated fats. These fats take the form of liquids at room temperature. Good sources of monounsaturated fats include:

  • avocados
  • nuts, such as almonds, peanuts, and Brazil nuts
  • seeds
  • vegetable oils, such as olive, peanut, sesame, and sunflower oils

In a 2019 study involving 119 adults with a high waist circumference, consuming a diet high in a monounsaturated fat called oleic acid resulted in lower LDL and total cholesterol levels than a diet higher in saturated fats and lower in monounsaturated fats. Oleic acid did not affect the triglycerides or HDL cholesterol levels in the participants’ blood.

Eat more polyunsaturated fats
Polyunsaturated fats include omega-3 and omega-6 fatty acids. Consuming these fats in moderation can reduce LDL cholesterol without affecting HDL cholesterol levels.

Dietary sources of polyunsaturated fats include:

  • walnuts
  • fish, such as salmon, tuna, and trout
  • plant oils, such as soybean, corn, and sunflower oils

2017 review found evidence suggesting that diets rich in polyunsaturated fats from fish oil may prevent some mechanisms of arrhythmia, which is an irregular heartbeat, and promote overall heart health.

It is important to balance the intake of omega-6 fatty acids with that of omega-3 fatty acids. Consuming too many omega-6 fatty acids may cause adverse health effects. In a 2018 study, mice that consumed a diet high in omega-6 fatty acids had low-grade chronic inflammation due to oxidative stress.

Why take Statins?[17]
If you have a high level of LDL cholesterol, it is potentially dangerous, as it can lead to a hardening and narrowing of the arteries (atherosclerosis) and cardiovascular disease (CVD). CVD is a general term that describes a disease of the heart or blood vessels. It’s the most common cause of human death in the UK.

The main types of CVD are:

  • Coronary heart disease – when the blood supply to the heart becomes restricted.
  • Angina – chest pain caused by reduced blood flow to the heart muscles.
  • Heart attacks – when the blood supply to the heart is suddenly blocked.
  • Stroke – when the supply of blood to the brain becomes blocked.

A doctor may recommend taking statins if either:

  • You have been diagnosed with a form of CVD.
  • Your personal and family medical history suggests you’re likely to develop CVD at some time over the next ten years, and lifestyle measures have not reduced this risk.

Statins explained[18]
Statins come as tablets that are taken once a day. For some types of statin, it does not matter what time of day you take it, as long as you stick to the same time. Some types of statin should be taken in the evening.

You should check with your doctor whether there’s a particular time of day you should take your statin. If you forget to take your dose, do not take an extra one to compensate for it. Just take your next dose, as usual, on the following day.


  • Statins can sometimes interact with other medicines, increasing the risk of unpleasant side effects, such as muscle damage.
  • Some types of statin can also interact with grapefruit juice.
  • It’s very important to read the information leaflet that comes with your medicine to check if there are any interactions about which you should be aware.

You usually have to continue taking statins for life because if you stop taking them, your cholesterol will return to a high level within a few weeks.

Statins and your Liver[19]
Statins should not be taken if you have severe liver disease or if blood tests suggest your liver may not be working properly. Statins can affect your liver, which is more likely to cause serious problems if you already have a severely damaged liver.

  • Before taking statins for the first time, you should have a blood test to ensure your liver is in relatively good condition.
  • You should also have a routine blood test to check the health of your liver three months after treatment begins and again after 12 months.

The prescription of statins may be challenging in patients with chronic liver disease, especially when an elevation of liver enzymes is present[20]. Despite a general agreement that statins may be safely prescribed to NAFLD patients,[21] firm data supporting this recommendation are still lacking[22].

Things that can increase this risk include:

  • being over 70 years old
  • having a history of liver disease
  • regularly drinking large quantities of alcohol
  • having a history of muscle-related side effects when taking a statin or fibrate (another type of medicine for high cholesterol)
  • having a family history of myopathy[23] or rhabdomyolysis[24]

If one or more of these apply to you, you may need to be frequently monitored to check for complications. A lower dose of statin may also be recommended.

If you have an underactive thyroid (hypothyroidism[25]), treatment may be delayed until this problem is treated. The reason is that having an underactive thyroid can lead to an increased cholesterol level, and treating hypothyroidism may cause your cholesterol level to decrease without the need for statins. Statins are also more likely to cause muscle damage in people with an underactive thyroid.

Read more about the side effects of statins on the NHS website[26].

It’s a good idea to discuss the benefits and risks of taking statins with your doctor before you start taking the medicine. If you find certain side effects particularly troublesome, talk to your GP. Your dose may need to be adjusted, or you may need a different type of statin. The main side effects of statins are listed below. Some of these will not necessarily apply to the specific statin you’re taking. For details of the side effects of a particular statin, check the information leaflet that comes with your medicine.

Common side effects
Side effects can vary between different statins, but common side effects include:

  • headache
  • dizziness
  • feeling sick
  • feeling unusually tired or physically weak
  • muscle pain
  • sleep problems
  • low blood platelet count
  • digestive system problems, such as constipation, diarrhoeaindigestion or passing wind

Uncommon side effects
Uncommon side effects of statins include:

Rare side effects
Rare side effects of statins include:

  • muscle weakness (myopathy)
  • loss of sensation or tingling in the nerve endings of the hands and feet (peripheral neuropathy)
  • tendon problems (tendons are tough cords of tissue that connect muscles to bones)

Muscle effects
Statins can occasionally cause muscle inflammation (swelling) and damage. Speak to your doctor if you have muscle pain, tenderness or weakness that cannot be explained – for example, pain that is not caused by physical work.

Your doctor may carry out a blood test to measure a substance in your blood called creatine kinase (CK), which is released into the blood when your muscles are inflamed or damaged. If the CK in your blood is more than five times the normal level, your GP may advise you to stop taking the statin. Regular exercise can sometimes lead to a rise in CK, so tell your doctor if you’ve been exercising a lot. Once your CK level has returned to normal, your doctor may suggest you re-start taking the statin, but at a lower dose.

Reporting side effects
The Yellow Card Scheme allows you to report suspected side effects from any medicine you may be taking.

It’s run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA).

See the Yellow Card Scheme website for more information.

Alternatives to Statins
If you’re at risk of developing CVD in the near future, your doctor will usually recommend lifestyle changes to reduce this risk before suggesting that you take statins. Lifestyle changes that can reduce your cholesterol level and CVD risk include:

  • eating a healthy, balanced diet
  • exercising regularly
  • maintaining a healthy weight
  • limiting the amount of alcohol you drink
  • stopping smoking

Statins may be recommended if these measures do not help. Read more about treating high cholesterol and preventing CVD.

Cholesterol-lowering alternatives to Statins[27]
Many other medicines and natural alternatives are claimed to lower cholesterol, but none of these work as well as statins. Here are the main ones you might come across:

  • Fibrates: Mostly used for lowering triglyceride levels in patients whose levels are very high and could cause pancreatitis. While they have a modest effect on lowering LDL cholesterol (15 to 20 per cent), they have not been shown to reduce the risk of heart attack or stroke and are not recommended as a statin alternative.
  • Plant stanols and sterols: There is some evidence that foods containing these stanols and sterols (such as specially fortified sunflower spreads and yoghurt drinks) can lower cholesterol by a modest amount (eight to 12 per cent). However, there is no evidence they reduce the risk of heart attack or stroke and they’re not recommended for prescription in the UK.
  • Cholestyramine and other bile acid-binding resins: These are relatively old drugs used before statins. They are still used occasionally but are no longer recommended for reducing the risk of future heart attacks or strokes. They may cause gastrointestinal side effects and lead to vitamin deficiencies if used long-term.
  • Niacin: Some evidence shows that niacin (vitamin B3 or nicotinic acid) can lower ‘bad’ LDL cholesterol and raise ‘good’ high-density lipoprotein (HDL) cholesterol, but little evidence that it reduces the risk of heart attack or stroke. It commonly causes intense skin flushing and is not recommended as an alternative to statins.
  • Policosanol: Policosanol is extracted from sugarcane wax and has been reported to lower cholesterol and improve various medical conditions. However, there is little reliable evidence that it works, and some studies show no effect at all.
  • Red yeast rice extract (RYRE): RYRE comes from the fermentation of a type of yeast found in rice and is sold as a supplement. It appears to lower LDL cholesterol (by 15 to 25 per cent) by working in a similar way to a low dose of a statin. Unlike statins, there is a lack of research into their long-term safety, uncertainty about the best dose and the amount of the active ingredient can vary widely.
  • Natural products: Many products claim to have a cholesterol-lowering effect, but most are lacking in solid evidence, and they are not an alternative to statins. Oats contain a fibre called beta-glucan, which can help lower your cholesterol level if you have 3g or more of it daily as part of a healthy diet (a 40g serving of porridge oats contains 2g of beta-glucan), but this will not deliver the same benefits as a statin.

The British Heart Foundation has a video explaining how statins reduce your cholesterol levels[28].

Risk of Diabetes[29]
Research such as a BHF-funded study has found that people on statins have a slightly increased risk of developing type-2 diabetes. It is a low chance, and your doctor would weigh up the potential risks and benefits for you before suggesting statins and should make any risks clear. The research also highlights that those on the highest doses of statins have the highest risk of developing type-2 diabetes. But people who are prescribed the highest dose are usually those who already have evidence of heart disease, and it is this group that needs the protection of statins most. While statins may increase the blood sugar level in some people, this does not offset the overall benefit that statins provide. If you take statins, watch your diet and exercise regularly.

Types of Statin[30]
There are five types of statin available on prescription in the UK:

If you want to Lower your Cholesterol, try Nuts[31]
Nuts are a kind of fruit with a hard outer shell. The exception is the peanut, which is a legume[32]. Nuts are a popular food worldwide, and there is evidence that they may benefit a person’s health. A variety of nuts may lower low-density lipoproteins (LDL) or “bad” cholesterol while raising high-density lipoproteins (HDL) or “good” cholesterol, but not all nuts have the same effect on a person’s cholesterol levels.

Perhaps a key question is: Can eating too many nuts raise cholesterol? The answer is yes, it is possible that eating nuts in excess may increase LDL cholesterol levels due to their saturated fat content. Eating nuts in excess may also exceed a person’s daily calorie needs, leading to increased LDL cholesterol levels. However, saturated fat content varies between different types of nuts, and eating certain nuts in moderation as part of a balanced diet may increase HDL cholesterol levels. However, people may improve their cholesterol levels by adding certain types of nuts to a balanced diet. A healthcare professional can offer further advice and help individuals manage their diet to reduce LDL cholesterol levels.

A list of nuts and their effect on cholesterol is given below:

  • Peanuts: According to a 2016 review, peanuts are rich in chemicals called phytosterols. These chemicals may stop the body from absorbing as much cholesterol since they are similar in structure to cholesterol and compete with it in absorption. Eating peanuts can lower a person’s total cholesterol and LDL cholesterol levels without making significant changes to their HDL cholesterol levels, according to an article at MedicalNewsToday[33].
  • Walnuts: A 2018 meta-analysis stated that walnuts are also high in phytosterols, which people may also call plant sterols. After reviewing 26 studies, the authors of the MedicalNewsToday article concluded that a person might lower LDL cholesterol levels by eating walnuts. However, this effect was more pronounced when walnuts contributed between 10% and 25% of a person’s daily energy intake. There was less of an impact when that figure was less than 10%.
  • Cashew Nuts: According to a 2017 study, incorporating cashew nuts into a typical [American] diet can help people decrease their total and LDL cholesterol levels. However, the researchers of a 2020 meta-analysis investigated the effects of cashews on cholesterol levels. They found that cashew consumption had no significant effect on total, LDL, or HDL cholesterol, and further research into cashews and cholesterol may be necessary.

Picture Credit: “IMG_3080” by beggs is licensed under CC BY 2.0.

  • Almonds: The authors of a 2018 review noted that supplementing the diet with almonds can lower LDL cholesterol while maintaining or even increasing HDL cholesterol. The authors suggested that people may reduce their risk of developing dyslipidemia — blood lipid levels that are too high or low — by eating 45g of almonds daily. Dyslipidemia is a risk factor for cardiovascular disease.
  • Hazelnuts: The authors of a 2016 review and meta-analysis compared the results of nine studies on hazelnuts and cholesterol. They found people who incorporated hazelnuts into their diet had lower levels of total and LDL cholesterol, with no effect on their HDL cholesterol. The study authors hypothesised that the high dietary fibre content of hazelnuts might contribute to this effect. According to the USDA, 100g of unroasted hazelnuts contain 9.7g of fibre.
  • Macadamia Nuts: There is limited recent research into the effects of macadamia nuts on cholesterol. However, a small 2003 study indicated that macadamia nut consumption could lower LDL levels by around 5.3% while increasing HDL levels by 7.9% among men with elevated cholesterol levels.
  • Brazil Nuts: A small 2013 study indicated that a single Brazil nut serving of 20–50g lowered LDL cholesterol levels and raised HDL cholesterol levels after 9 hours in 10 healthy study participants. Conversely, the authors of a 2022 meta-analysis reported no significant changes in cholesterol levels after Brazil nut consumption. Therefore, further research into Brazil nuts and cholesterol may be necessary.
  • Pecan Nuts: A 2018 study indicated that people might lower their LDL cholesterol levels by consuming a high pecan diet. However, the authors concluded that further research is necessary.
  • Pistachios: A 2016 review investigated the results of nine studies into the relationship between blood cholesterol and pistachio nut consumption. In six of those studies, LDL cholesterol levels dropped while HDL cholesterol levels rose in people who replaced part of their usual diet with pistachio nuts.

Picture Credit: “Lipid 8098” by UGA CAES/Extension is licensed under CC BY-NC 2.0.

Picture Credit: Dungodung, Public domain, via Wikimedia Commons “Fruits are zero-cholesterol foods.”
File URL:

Sources and Further Reading

CAUTION: This paper is not medical advice. No advice is implied or given in articles published by us but is only for general information. You should always seek the advice of your GP or other qualified health provider with any questions you may have regarding a medical condition. This paper is compiled from the sources stated but has not been medically reviewed. It should never be used as a substitute for obtaining advice from a Cardiologist or other qualified clinician/medical practitioner. If you have already been given dietary advice, you should not make changes without first talking to your GP, consultant or dietitian. Any medications mentioned may include names for US drugs which may have a different name to those available in the UK. The facts are believed to be correct as at the date of publication, but there may be certain errors and omissions for which we cannot be responsible. There is no implied endorsement or promotion of any organisation by the writer. The hyperlinks were valid at the date of publication.

  1. Source:
  2. Source:
  3. Source: Cholesterol at the US National Library of Medicine Medical Subject Headings (MeSH)
  4. “Cholesterol, 57-88-5”. PubChem, National Library of Medicine, US National Institutes of Health. 9th November 2019.
  5. Explanation: Biosynthesis is the production of a chemical compound by a living organism. Source:
  6. Source: Hanukoglu I (December 1992). “Steroidogenic enzymes: structure, function, and role in regulation of steroid hormone biosynthesis”. The Journal of Steroid Biochemistry and Molecular Biology. 43 (8): 779–804.
  7. Source: Razin S, Tully JG (May 1970). “Cholesterol requirement of mycoplasmas”. Journal of Bacteriology. 102 (2): 306–10.
  8. Source:
  9. Source:
  10. Sources: (1) Chevreul (1816) “Recherches chimiques sur les corps gras, et particulièrement sur leurs combinaisons avec les alcalis. Sixième mémoire. Examen des graisses d’homme, de mouton, de boeuf, de jaguar et d’oie” (Chemical researches on fatty substances, and particularly on their combinations o filippos ine kapios with alkalis. Sixth memoir. Study of human, sheep, beef, jaguar and goose fat), Annales de Chimie et de Physique2 : 339–372. From page 346 : “Je nommerai cholesterine, de χολη, bile, et στερεος, solide, la substance cristallisée des calculs biliares humains, … ” (I will name cholesterine – from χολη (bile) and στερεος (solid) – the crystalized substance from human gallstones … ), and (2)  Olson RE (February 1998). “Discovery of the lipoproteins, their role in fat transport and their significance as risk factors”. The Journal of Nutrition. 128 (2 Suppl): 439S–443S.
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  20. Sources: (1) Eslami L, Merat S, Malekzadeh R, Nasseri-Moghaddam S, Aramin H. Statins for non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. Cochrane Database Syst Rev. 2013; 12:CD008623, and (2) Del Ben M, Baratta F, Polimeni L, et al. Under-prescription of statins in patients with non-alcoholic fatty liver disease. Nutr Metab Cardiovasc Dis. 2017; 27: 161- 167.
  21. Source: Pastori D, Polimeni L, Baratta F, Pani A, Del Ben M, Angelico F. The efficacy and safety of statins for the treatment of non-alcoholic fatty liver disease. Digest Liver Dis. 2015; 47(1): 4- 11.
  22. Source:
  23. Explanation: Myopathy is a general term referring to any disease that affects the muscles that control voluntary movement in the body. Patients experience muscle weakness due to a dysfunction of the muscle fibres. Some myopathies are genetic and can be passed from parent to child.
  24. Explanation: Rhabdomyolysis (rhabdo) is the breakdown of damaged skeletal muscle. Muscle breakdown causes the release of myoglobin into the bloodstream. Myoglobin is the protein that stores oxygen in your muscles. If you have too much myoglobin in your blood, it can cause kidney damage. It also releases huge amounts of potassium into the bloodstream, which can disrupt the electrical rhythm of the heart. Source:
  25. Explanation: An underactive thyroid gland (hypothyroidism) is where your thyroid gland does not produce enough hormones. Common signs of an underactive thyroid are tiredness, weight gain and feeling depressed. An underactive thyroid can often be successfully treated by taking daily hormone tablets to replace the hormones your thyroid is not making. Source: © Crown Copyright acknowledged.
  26. At: ©Crown Copyright acknowledged
  27. Source: British Heart Foundation, at:
  28. At:
  29. Source:
  30. Source: © Crown Copyright acknowledged
  31. Source:
  32. Explanation: A legume is a plant in the family Fabaceae, or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock forage and silage, and as soil-enhancing green manure. Source:
  33. At:


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