CAS No. Registry Number 9051-97-2
Beta-glucan is a fiber-type complex sugar (polysaccharide) derived from the cell wall of baker’s yeast, oat and barley fiber, and many medicinal mushrooms, such as maitake. In their natural states, yeast and mushrooms contain a mixture of beta-1,3-glucan and beta-1,6-glucan. Oats and barley contain a mixture of beta-1,3-glucan and beta-1,4-glucan. In addition to purified beta-1,3-glucan from these sources, you may see products listed as beta-1,3/1,6-glucan in the case of yeast-derived products and as beta-1,3/1,4-glucan when derived from oats. Similar (if not identical) properties have been shown for beta-glucan-rich extracts and purified beta-glucan derived from oats, baker’s yeast, and mushrooms.
The two primary uses of beta-glucan are to enhance the immune system and to lower blood cholesterol levels. Numerous experimental studies in test tubes and animals have shown beta-glucan to activate white blood cells.1 2 3 4 5 In fact, there have been hundreds of research papers on beta-glucan since the 1960s.6 The research indicates that beta-1,3-glucan, in particular, is very effective at activating white blood cells known as macrophages and neutrophils. These cells provide one of the immune system’s first lines of defense against foreign invaders. A beta-glucan-activated macrophage or neutrophil can recognize and kill tumor cells, remove cellular debris resulting from oxidative damage, speed up recovery of damaged tissue, and further activate other components of the immune system.7 8 Although the research in test tube and animal studies is promising, many questions remain about the effectiveness of beta-glucan as an oral supplement to enhance immune function in humans.
Beta-glucan is the key factor for the cholesterol-lowering effect of oat bran.9 10 11 12 13 As with other soluble-fiber components, the binding of cholesterol (and bile acids) by beta-glucan and the resulting elimination of these molecules in the feces is very helpful for reducing blood cholesterol.14 15 16 Results from a number of double-blind trials with either oat- or yeast-derived beta-glucan indicate typical reductions, after at least four weeks of use, of approximately 10% for total cholesterol and 8% for LDL ("bad") cholesterol, with elevations in HDL ("good") cholesterol ranging from zero to 16%.17 18 19 20 21
Like other sources of soluble fiber, beta-glucan is, according to preliminary studies, helpful in reducing the elevation in blood sugar levels that typically follow a meal.22 23 24 25 Beta-glucan produces this effect by delaying gastric emptying so that dietary sugar is absorbed more gradually, as well as by possibly increasing the tissue sensitivity to insulin. These effects suggest possible benefit in blood sugar control in people with diabetes.
Beta-glucan is found in the cell walls of many yeast and cereal fibers, such as oats, wheat, and barley. As a dietary supplement, beta-glucan is available in liquid form as well as in capsules and tablets.
Beta-glucan has been used in connection with the following conditions (refer to the individual health concern for complete information):
Rating Health Concerns
Reliable and relatively consistent scientific data showing a substantial health benefit.
Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
Because beta-glucan is not an essential nutrient, deficiencies do not occur.
How much is usually taken?
For lowering cholesterol levels, the amount of beta-glucan used in clinical trials has ranged from 2,900 to 15,000 mg per day. For enhancing immune function, an effective amount has not yet been determined due to the lack of studies in this application. However, manufacturers of beta-glucan products usually recommend between 50 and 1,000 mg daily (to be taken on an empty stomach), although some products contain as much as 500 mg per capsule.
No side effects have been reported.
At the time of writing, there were no well-known drug interactions with beta-glucan.