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Beta-glucan (oat & barley)

A viscous fibre with an official green light for lowering cholesterol — 3 grams a day.

Reviewed by Bodil Isaksson, Licensed Biomedical Scientist (Sweden)Last reviewed July 2026Supplement guide

SupplementsFiberSoluble fibreCholesterolBlood sugar

Beta-glucan is the soluble fibre in oats and barley. It is one of very few supplement ingredients with authorised EU health claims — for cholesterol and post-meal blood sugar.

Key takeaways

  • EFSA-approved: 3 g/day of oat or barley beta-glucan lowers LDL cholesterol.1
  • Also blunts the blood-sugar rise after a carbohydrate meal (approved claim).1
  • Works by forming a thick gel — so whole/least-processed oats and barley keep the viscosity that matters.
  • This is not the same as yeast/mushroom beta-glucan sold for immunity, which has much weaker evidence.

What it is

A gel-forming soluble fibre (1,3/1,4-beta-glucan) concentrated in oat and barley bran. Its viscosity in the gut traps bile acids, forcing the liver to pull cholesterol from the blood to make more.

The evidence

EFSA has authorised claims that 3 g/day of oat/barley beta-glucan reduces blood cholesterol and that beta-glucans reduce the post-prandial glucose rise.1 Meta-analyses put the LDL reduction at roughly 5–10%.2

Dose

3 g/day of beta-glucan — about 70–100 g of oats, or a measured oat/barley beta-glucan supplement. Processing that destroys viscosity (very fine milling) weakens the effect.

Safety & the immune-type caveat

Very safe; mild gas. Note the label: oat/barley beta-glucan (fibre, cholesterol) is a different molecule from yeast/mushroom (1,3/1,6) beta-glucan marketed for immune support — the immune claims are far less established.

Bottom line: one of the best-evidenced fibres — 3 g/day of oat or barley beta-glucan measurably lowers LDL; don’t confuse it with the immune yeast type.

References

Adult research summary for education, not a prescription.

  1. EFSA Panel on Dietetic Products (NDA): scientific opinions on beta-glucans from oats and barley and maintenance of normal blood cholesterol / reduction of post-prandial glycaemic responses. EFSA Journal 2011. www.efsa.europa.eu
  2. Ho HVT, et al. The effect of oat beta-glucan on LDL cholesterol: a systematic review and meta-analysis. Br J Nutr 2016. pubmed.ncbi.nlm.nih.gov

This article summarises nutrition science for education. It is not a substitute for individual medical advice; consult a professional before starting a supplement, in pregnancy, or alongside medication.