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Information about cholesterol can sometimes come hand in hand with baffling terminology. However, most of these terms actually have a pretty simple explanation. So what about ‘serum cholesterol levels’? To help you understand this term a little better, we’ve collected answers to the key questions below.

What does serum mean?

‘Serum’ is simply a medical term for one component of blood. In medicine, many different bodily markers are measured in terms of how much is in the serum portion of the blood. So, when you hear the term ‘serum’, it just means how much is in that part of the blood. In fact, you will often see serum cholesterol often just simply referred to as blood cholesterol.

So, what is serum cholesterol?

The total serum cholesterol level is the amount of cholesterol in the blood. A high serum cholesterol level is a concern, because it raises your risk of heart disease. When people talk about getting their cholesterol checked or finding out their cholesterol levels, they are usually referring to serum cholesterol levels.

What should your normal serum cholesterol levels be?

The NHS as a general guide say that total cholesterol levels should be: 5mmol/L or less for healthy adults, or 4mmol/L or less for those at high risk of developing heart disease*.

Within total serum cholesterol, there are a few measurements that give a more detailed view of whether your cholesterol levels are okay.

Your doctor may talk about non-HDL cholesterol. This is because LDL was previously used as the main measure of bad cholesterol, and is still a good indicator, but we now know that other forms of non-HDL cholesterol are also harmful, and this test may be a more accurate way of estimating risk.

If you are unsure what your cholesterol results mean, you should speak to your GP, nurse or pharmacist.

How to reduce serum cholesterol levels

There are simple changes to your diet you can make to reduce your serum cholesterol levels:

  • Replace saturated fat in the diet with some unsaturated fat**.
  • Eat foods with added plant sterols or stanols, like those in the Flora ProActiv range***.
  • Include foods rich in soluble fibre such as beta-glucan (found in oats and barley)

In addition to this, it’s important to have a healthy diet and lifestyle overall:

  • Have a balanced diet, with a variety of at least 5 portions of fruit and vegetables, higher fibre starchy foods(choose wholegrain or higher fibre versions with less added fat, salt and sugar), dairy and dairy alternatives (choose lower fat and lower sugar options), as well as beans, pulses, fish, eggs, lean meat and other protein sources.
  • Maintain a healthy weight
  • Avoid unhealthy habits, like smoking and drinking in excess.
  • Have an active lifestyle. Try to do at least 150 minutes of physical activity a week.

Like some help? Sign up for our cholesterol lowering starter kit! It’s completely free, and is a great way to get started on your cholesterol lowering journey. Good luck!

* High cholesterol is a risk factor in the development of coronary heart disease. As coronary heart disease has many risk factors, more than one may need to be improved to reduce overall risk, and individual results may vary.
** Replacing saturated fats with unsaturated fats in the diet has been shown to lower blood cholesterol. High cholesterol is a risk factor in the development of coronary heart disease. There are many risk factors for coronary heart disease and it is important to take care of all of them to reduce the overall risk of it.

BNF suggested references:

  1. National Institute for Health and Care Excellence (NICE). Clinical knowledge summaries: Lipid modification – CVD prevention (revised October 2015). (accessed 20/05/2019)
  2. NHS Digital (2018). High cholesterol. (accessed 20/05/2019)
  3. British Heart Foundation. High Cholesterol – Causes, Symptoms & Treatments. (accessed 21/05/2019)
  4. Hooper L et al.(2015). Reduction in saturated fat intake for cardiovascular disease. Cochrane database of systematic reviews. (accessed 21/05/2019)
  5. Commission Regulation (EU) No 686/2014 as 20 June 2014 amending Regulations (EC) No 983/2009 and (EU) No 384/2010 as regards the conditions of use of certain health claims related to the lowering effect of plant sterols and plant stanols on blood LDL-cholesterol. (accessed 20/05/2019)
  6. British Nutrition Foundation (2019). CARDIOVASCULAR DISEASE: Diet, Nutrition and Emerging Risk Factors, 2nd Edition. Wiley Blackwell.

The British Nutrition Foundation has reviewed the accuracy of the scientific content of this page in May 2019 (please note this does not include linked pages). The Foundation does not endorse any brands or products.  For more information about the Foundation, please visit

This information has been included in good faith, but is for general informational purposes only, and should not be construed as a guarantee. The nutritional facts and statements on this site are designed for educational and resource purpose sonly, not being substitutes for professional advice. If you have any concerns or questions about your health, you should always check with your GP or healthcare professional.