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Oats & barley

This HEART UK Nutrition Academy webpage has been funded by Novartis Pharmaceuticals UK Ltd who have had no input into the content or development of this material.

Oats and barley are whole grains that are rich in the viscous dietary fibre beta-glucan, which has been proven to lower total cholesterol, LDL cholesterol and non-HDL cholesterol levels1,2.

Take home messages

  • Oats and barley are rich in the fibre beta-glucan.
  • 3g beta-glucan daily has been proven to lower:
    • total cholesterol by 0.25-0.66mmol/L
    • LDL cholesterol by 0.24-0.6mmolL.
  • Health claims for oat's and barley's beta-glucan benefit for cardiovascular health and lipid lowering has been approved by the European Commission and American Food and Drug Association.

The evidence

The wealth of evidence to support beta-glucans has resulted in the FDA approving the health claim: 

“consumption of 3g or more per day of beta-glucan soluble fibre from either whole oats or barley, or a combination of whole oats and barley, as part of a low saturated fat and cholesterol diet, may reduce the risk of heart disease”3.  

In 2011 and 2012, the EFSA also approved a claim for 3g daily of beta-glucan from barley or oats to lower blood cholesterol7,8.

Since then, further meta-analyses of randomised controlled trials have consistently demonstrated that around 3g of beta-glucan a day reduces total cholesterol by 0.25-0.66mmol/L and LDL cholesterol by 0.24-0.6mmolL9,10,15–17.

  • In 2014, a meta-analysis of 28 RCTs showed that a minimum of 3g of oat beta-glucans per day reduced LDL cholesterol by 0.25mmol/L – a 6% decrease compared to control groups9.
  • Two years later, a 2016 meta-analysis of 14 RCTs with 615 participants found a 0.25mmol/L drop in LDL cholesterol and a 0.31mmol/L decrease in non HDL cholesterol among those who ate 1.5g-12g daily of barley beta-glucan for four weeks16
  • A more comprehensive meta-analysis in 2016 analysed 58 RCTs with 3,974 participants who were given a daily dose of 3.5g of oat beta-glucan. The results showed significant reductions in LDL cholesterol (4.2%), non-HDL cholesterol (4.8%) and Apolipoprotein B (2.3%)10.
  • In 2023, a systematic review of 17 RCTs affirmed the previous findings, showing that a daily intake of approximately 3g of oat beta-glucans substantially lowered both total and LDL cholesterol levels18. This review also noted a triglyceride-reducing effect, especially among individuals who were overweight, had diabetes or had metabolic syndrome.

Proposed mechanism

The hypothesised cholesterol-lowering mechanism revolves around the ability of beta-glucans to interfere with the bile acid metabolism19,20.

  • Beta-glucans form a gel-like substance in the gut lumen which can bind to dietary cholesterol and bile acids which contain recycled cholesterol.
  • The binding of beta-glucans to bile acids results in the formation of complexes that are less readily absorbed from the small intestine and instead excreted through faeces, removing cholesterol from the body.
  • As some bile acids are excreted rather than re-absorbed, the liver has to produce new bile acid. In order to do this, the liver removes cholesterol circulating in the blood, thus helping to reduce blood cholesterol levels.

Additionally, beta-glucans may have a prebiotic effect, positively influencing gut bacteria which produce short-chain fatty acids (SCFA). SCFA can interfere with cholesterol metabolism and production20.

As the proposed mechanism differs from statin pathways, beta-glucans would further reduce serum cholesterol levels alongside statin therapy.

Effective dose: 3g beta-glucans daily

Achieving 3g a day  with oats and barley 

Choose any three of the following servings each day. Each of the following single servings contain around 1g of beta-glucan.
Food Single serve

How to achieve it

Porridge oats – one of the UK’s favourite breakfasts 30g oats
  • Serve as porridge or overnight oats
  • Use them to make home-made oat bars or in fruit crumble toppings
Oat-based breakfast cereal flakes 30-35g bowl
  • Check the label, they must be 100% oat-based
Oat cakes – reduced salt 3 oatcakes
  • A great snack – choose reduced salt varieties
Pearl barley

75g cooked or

25-30g raw

  • Can be used as an alternative carbohydrate to accompany meals instead of potatoes, rice or pasta
    Great to thicken stews and soups
    Use as a salad base
Oat bran 1-2 tbsp
  • Sprinkle over main meals such as stews, soups, curries or porridge

Watch our CPD e-module: The four cholesterol-lowering foods


Read about the other cholesterol-lowering foods 

Nuts Soya Sterols and stanol esters


  1. Sima P, Vannucci L, Vetvicka V. β-glucans and cholesterol (Review). Int J Mol Med. 2018;41(4):1799-1808. doi:10.3892/ijmm.2018.3411
  2. Whitehead A, Beck EJ, Tosh S, Wolever TM. Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials1234. The American Journal of Clinical Nutrition. 2014;100(6):1413-1421. doi:10.3945/ajcn.114.086108
  3. FDA. 21 CFR Part 101.81 - Health Claims: Soluble fibre from certain foods and risk of coronary heart disease (CHD). Accessed October 12, 2023.
  4. European Commission. Commission Regulation (EU) No 1048/2012 of 8 November 2012 on the authorisation of a health claim made on foods and referring to the reduction of disease risk - Barley beta-glucan. OJ L. 2012;310:38-40.
  5. European Commission. Commission Regulation (EU) No 1160/2011 of 14 November 2011 on the authorisation and refusal of authorisation of certain health claims made on foods and referring to the reduction of disease risk (Oat beta-glucan). OJ L. 2011;296:26-28.
  6. Tiwari U, Cummins E. Meta-analysis of the effect of β-glucan intake on blood cholesterol and glucose levels. Nutrition. 2011;27(10):1008-1016. doi:10.1016/j.nut.2010.11.006
  7. Ho HVT, Sievenpiper JL, Zurbau A, et al. The effect of oat β-glucan on LDL-cholesterol, non-HDL-cholesterol and apoB for CVD risk reduction: a systematic review and meta-analysis of randomised-controlled trials. British Journal of Nutrition. 2016;116(8):1369-1382. doi:10.1017/S000711451600341X
  8. Ho HVT, Sievenpiper JL, Zurbau A, et al. A systematic review and meta-analysis of randomized controlled trials of the effect of barley β-glucan on LDL-C, non-HDL-C and apoB for cardiovascular disease risk reductioni-iv. Eur J Clin Nutr. 2016;70(11):1239-1245. doi:10.1038/ejcn.2016.89
  9. Yu J, Xia J, Yang C, et al. Effects of Oat Beta-Glucan Intake on Lipid Profiles in Hypercholesterolemic Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2022;14(10):2043. doi:10.3390/nu14102043
  10. Amerizadeh A, Ghaheh HS, Vaseghi G, Farajzadegan Z, Asgary S. Effect of Oat (Avena sativa L.) Consumption on Lipid Profile With Focus on Triglycerides and High-density Lipoprotein Cholesterol (HDL-C): An Updated Systematic Review. Current Problems in Cardiology. 2023;48(7):101153. doi:10.1016/j.cpcardiol.2022.101153
  11. Wang Y, Harding SV, Thandapilly SJ, Tosh SM, Jones PJH, Ames NP. Barley β-glucan reduces blood cholesterol levels via interrupting bile acid metabolism. British Journal of Nutrition. 2017;118(10):822-829. doi:10.1017/S0007114517002835
  12. Joyce SA, Kamil A, Fleige L, Gahan CGM. The Cholesterol-Lowering Effect of Oats and Oat Beta Glucan: Modes of Action and Potential Role of Bile Acids and the Microbiome. Front Nutr. 2019;6:171. doi:10.3389/fnut.2019.00171

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