Beta-glucans are a type of fiber derived from cereals (e.g., oats, barley), seaweed, bacteria, and fungi. Their biological effects are influenced by their structure, which varies depending on the source. Cereal beta-glucans can lower cholesterol, while fungal beta-glucans may boost immunity.
Beta-glucans is most often used for
Last Updated:April 18, 2024
Beta-glucans are fibers found in the cell walls of various organisms, including cereals and fungi, and they have functions in glucose storage and structural integrity. They can be consumed through the diet (from sources like oats and mushrooms) or as supplements, and their biological activity varies based on their structure and source.
Beta-glucans from cereals, particularly oats and barley, can help reduce LDL and total cholesterol levels and promote satiety and may lead to slight weight loss. They also have the potential to lower postmeal blood glucose and insulin levels, although their effect on fasting blood glucose and HbA1c in type 2 diabetes is minimal and may not be clinically significant.
Beta-glucans are generally safe and well tolerated, and potential gastrointestinal side effects include diarrhea, constipation, nausea, flatulence, and abdominal cramping. Caution is advised for people with autoimmune diseases, and there is limited research on their safety during pregnancy.
Beta-glucans from oats and barley function as soluble, viscous fibers that slow gastric emptying, reduce glucose absorption, and enhance bile acid elimination, thus potentially lowering cholesterol. Fungal beta-glucans may modulate immune responses by interacting with immune cells, and their effects on the gut microbiome suggest possible prebiotic properties, although clinical evidence for these benefits is lacking.
Beta-glucans usually come as a powder that may be loose or in capsules. Oat and barley beta-glucans generally require larger doses, which is more easily achieved with a loose powder that can be added to food or beverages.
For lowering cholesterol, taking oat or barley beta-glucans orally at a dosage of at least 3 grams daily is recommended.[1] If choosing to supplement with whole foods, this can also be achieved with about 75 grams (2.6 ounces) of whole grain oats, 55 grams (2 ounces) of oat bran, or 45 grams (1.6 ounces) of barley.[2]
For lowering postmeal increases in blood glucose and insulin levels, adding around 3 grams (0.1 ounce) of oat beta-glucans per 30 grams (1 ounce) of carbohydrates seems to be effective.[3]
For reducing the incidence and duration of upper respiratory tract infections, taking yeast beta-glucans orally at a dosage of 250 mg daily for at least 4 weeks may be effective.[4]
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We created brand new FAQs on beta-glucans, including what they are, how they work, potential drawbacks, and their effects on metabolic health and immunity. We also added the most up-to-date meta-analyses to the Examine database.
