What are beta-glucans?
Beta-glucans are natural polysaccharides — long chains of glucose molecules found in various foods. The three main sources are oats, mushrooms (especially shiitake, maitake, and reishi), and yeast (Saccharomyces cerevisiae). Each source provides a slightly different type of beta-glucan with different biological properties.
Oat beta-glucans are soluble fibres that form a gel-like mass in the digestive tract. Mushroom and yeast beta-glucans, on the other hand, are insoluble and have been studied more in relation to the immune system. In Estonia and the Nordic countries, oats are a traditional staple food, making oat beta-glucans especially relevant.
How beta-glucans work
Oat beta-glucans work in the digestive tract, where they form a viscous gel that slows food transit and reduces cholesterol absorption (Whitehead et al., 2014). This mechanism is well studied and understood.
Mushroom and yeast beta-glucans work differently — they bind to immune cell receptors (primarily the Dectin-1 receptor), which may activate immune responses (Brown & Gordon, 2003). This mechanism is under active investigation.
Evidence and benefits
Oat beta-glucans have an approved EFSA health claim in the European Union: oat beta-glucans contribute to the maintenance of normal blood cholesterol levels (EFSA Panel on Dietetic Products, 2011). The condition for this claim is consumption of at least 3 g of oat beta-glucans per day.
Additionally, it is established that consuming oat beta-glucans as part of a meal reduces the post-meal rise in blood sugar (Tosh, 2013).
Regarding the immune system, research suggests:
- Mushroom and yeast beta-glucans have shown potential to modulate immune responses in studies
- Some clinical trials suggest beta-glucans may reduce the incidence of upper respiratory infections (Auinger et al., 2013)
- Among athletes, beta-glucans have been studied as immune support after intense training (Nieman et al., 2008)
Immune-related research is promising, but larger confirmatory studies are still needed.
How to take beta-glucans
For cholesterol support, at least 3 g of oat beta-glucans per day is needed. This corresponds to roughly 75 g of oat flakes. Supplements provide more concentrated forms.
Immune-supporting beta-glucans from mushrooms and yeast are available as capsules, typically in doses of 250–500 mg per day. These are best taken regularly, on an empty stomach in the morning.
Both types can be used long-term and are generally considered safe.
Who should consider beta-glucans
- People looking to support healthy cholesterol levels (oat beta-glucans)
- Those seeking immune system support, especially during seasonal changes (mushroom/yeast beta-glucans)
- Athletes wanting post-intensive-training immune support
- Individuals interested in increasing fibre intake
- Those wanting to support post-meal blood sugar stability
Consult a healthcare professional before starting any new supplement.
Frequently asked questions
What is the difference between oat and mushroom beta-glucans?
Oat beta-glucans are soluble fibres that work primarily in the digestive tract for cholesterol and blood sugar. Mushroom beta-glucans are insoluble and mainly affect the immune system. They are different compounds with different benefits.
Can I get enough beta-glucans from eating porridge?
For cholesterol support, 3 g per day is needed, which corresponds to about 75 g of oat flakes. This is achievable but requires daily oat consumption.
Are beta-glucans safe for people with allergies?
Oat beta-glucans are gluten-free, but cross-contamination risk may exist. Those with mushroom allergies should exercise caution with mushroom beta-glucans.
Do beta-glucans cause digestive issues?
Oat beta-glucans are fibres and may initially cause gas in larger amounts. Start with a smaller dose and increase gradually.
Can beta-glucans be combined with probiotics?
Yes, this is a common and well-tolerated combination. Beta-glucans may even act as prebiotics.
Can children take beta-glucans?
Oat beta-glucans from food (porridge) are suitable for children. For supplements, consult a paediatrician.
References
1. EFSA Panel on Dietetic Products, Nutrition and Allergies. (2011). Scientific Opinion on the substantiation of health claims related to beta-glucans from oats and barley and maintenance of normal blood LDL-cholesterol concentrations. EFSA Journal, 9(6), 2207.
2. Tosh SM. (2013). Review of human studies investigating the post-prandial blood-glucose lowering ability of oat and barley food products. European Journal of Clinical Nutrition, 67(4), 310-317.
3. Brown GD, Gordon S. (2003). Fungal beta-glucans and mammalian immunity. Immunity, 19(3), 311-315.
4. Auinger A, Riede L, Bothe G, et al. (2013). Yeast (1,3)-(1,6)-beta-glucan helps to maintain the body's defence against pathogens: a double-blind, randomized, placebo-controlled, multicentric study. European Journal of Nutrition, 52(8), 1913-1918.
5. Nieman DC, Henson DA, McMahon M, et al. (2008). Beta-glucan, immune function, and upper respiratory tract infections in athletes. Medicine and Science in Sports and Exercise, 40(8), 1463-1471.
6. Whitehead A, Beck EJ, Tosh S, Wolever TM. (2014). Cholesterol-lowering effects of oat beta-glucan: a meta-analysis of randomized controlled trials. American Journal of Clinical Nutrition, 100(6), 1413-1421.
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Disclaimer
A food supplement is not a substitute for a varied and balanced diet and a healthy lifestyle.
