Beta-Glucan in Foods: Oats, Barley and Mushrooms
What beta-glucan is, which foods contain it (oats, barley, mushrooms), what trials found for LDL cholesterol, and why cereal and mushroom beta-glucans are not interchangeable.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
Short answer: Beta-glucan is a type of soluble fiber. For oat beta-glucan there is good trial evidence of a modest drop in LDL ("bad") cholesterol. For mushroom beta-glucan the sources we read say that cholesterol-type effects still need confirming in human studies.
What beta-glucan is and where it occurs
Beta-glucans are chains of glucose units. Cereals such as oats (Avena sativa) and barley (Hordeum vulgare) contain them, and so do mushroom cell walls. [1][2] A review notes that mushroom beta-glucans have 1,6 linkages and branching structures, while cereal beta-glucans have neither. [2] In the gut, oat and barley beta-glucans thicken the contents of the intestine (viscosity), which is thought to explain part of their effects on cholesterol and after-meal blood sugar. [3] That review also says processing can change the structure and properties of beta-glucans. [3]
What research shows
| Question | What the source found | Strength of evidence |
|---|---|---|
| Oat beta-glucan and LDL cholesterol | A meta-analysis of 28 randomized trials found 3 g or more a day lowered LDL by 0.25 mmol/L and total cholesterol by 0.30 mmol/L versus control. HDL and triglycerides did not change. [4] | Established for LDL (a blood marker; trials lasted 2 to 12 weeks) |
| Does the amount matter? | The same analysis found no evidence that dose (3.0 to 12.4 g a day) or duration changed the result. [4] | Established within the range studied |
| Who benefits most? | LDL lowering was greater when baseline LDL was higher. [4] | Limited subgroup finding |
| Barley | A review describes oats and barley together as sources of heart-health and blood-sugar effects through soluble fiber. [3] | Promising but limited (we did not read a barley-only meta-analysis) |
| Mushroom beta-glucan and cardiovascular effects | The review says activities seen for oat and barley beta-glucans "require confirmation in human studies with mushroom" beta-glucans. [2] | Insufficient evidence |
| Mushroom beta-glucan and immune or cancer uses | The review describes cell and animal studies and some clinical testing, such as for respiratory infections. [2] | Preclinical, with early human work |
Food versus supplement
The trial evidence above concerns oat products and added oat beta-glucan eaten in the diet. Isolated mushroom beta-glucan extracts are a different product, and results for one do not transfer to the other. For how mushroom label numbers are read, see beta-glucans versus total polysaccharides.
Frequently asked questions
How much oat beta-glucan did the trials use?
The meta-analysis looked at trials giving 3 g or more of oat beta-glucan a day, with a range of 3.0 to 12.4 g a day across the trials. [4] This describes the studies, not a recommended amount for a person.
Is beta-glucan the same in oats and mushrooms?
No. A review states that cereal beta-glucans lack the 1,6 linkages and branching found in mushroom beta-glucans. [2]
Does cooking or processing change oat beta-glucan?
A review says processing conditions can alter the composition and physical properties of beta-glucans. [3] We did not read a source that ranks particular oat products.
Did the trials show fewer heart attacks?
The meta-analysis we read measured cholesterol, not heart attacks or strokes. [4]
Where do I read about cholesterol and food overall?
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
What regulators say
The US Food and Drug Administration's rules allow a heart-disease claim for foods with soluble fiber, including 3 g or more a day of beta-glucan from whole oats or barley, as part of a diet low in saturated fat and cholesterol. [5] A claim like this is a regulatory statement about a food, not a promise of results for any one person.
Limits and safety
- The cholesterol results are for a marker. They do not show fewer heart attacks.
- A 2014 meta-analysis found no clear effect on HDL or triglycerides. [4]
- Gluten and oats, and other food-specific points, are on the oats page. Barley is covered on the barley page.
- We did not read a source on medicine interactions with beta-glucan foods, so this is not described here. If you take cholesterol or diabetes medicines, ask the prescriber or a pharmacist before making big diet changes.
References
- GBIF Backbone Taxonomy species match. Global Biodiversity Information Facility. Accepted names checked 2026-10-23.
- Edible Mushrooms and Beta-Glucans: Impact on Human Health. Nutrients 2021. PMID 34202377. Read 2026-10-23.
- Emerging science on benefits of whole grain oat and barley and their soluble dietary fibers for heart health, glycemic response, and gut microbiota. Nutr Rev 2020. PMID 32728756. Read 2026-10-23.
- Cholesterol-lowering effects of oat β-glucan: a meta-analysis of randomized controlled trials. Am J Clin Nutr 2014. PMID 25411276. Read 2026-10-23.
- 21 CFR 101.81, Health claims: soluble fiber from certain foods and risk of coronary heart disease. US Electronic Code of Federal Regulations. Read 2026-10-23.