Beta glucan is a form of fiber found in many foods, particularly mushrooms long prized in Asian medicine for their medicinal value. Strong evidence supports the heart-health benefits of beta glucans; the U.S. Food and Drug Administration allows manufacturers to label products containing this substance as "heart healthy." Beta-glucan also appears to stimulate immune function in various ways and evidence suggests it might strengthen the immune system, which would potentially benefit a wide range of conditions. The Beth Israel Deaconess Medical Center notes that not enough evidence exists as of 2011, however, to make any definitive conclusions about its therapeutic applications in this area. Some dosage guidelines exist but a maximum dosage has not been established. If you believe taking beta glucan will benefit a particular health concern, talk to your doctor about an appropriate dose.
The Beth Israel Deaconess Medical Center notes that studies looking at beta glucan’s effect on high cholesterol administered dosages between 3,000 to 15,000 mg. Results suggests the higher end of the dosage spectrum produces better results. As for stimulating immune function, a lack of research investigating this particular use makes it difficult to determine minimum and maximum doses. The University of Michigan Health System notes that most manufacturers of beta glucan supplements suggest daily doses up to 1,000 mg daily for this purpose.
Since beta glucan naturally occurs in food, it appears a generally safe supplement with little risk of side effects. Drugs.com notes animal studies found large doses of beta glucan did not induce toxicity or mortality.
No medication interactions have been documented in scientific literature. If you take any prescription drugs, however, always check with your doctor before using any supplement.
Other Considerations for Use
Beta glucan’s potential to stimulate the immune system could potentially prove problematic if you have any condition resulting from an overactive immune system such as an autoimmune disease or if you received an organ transplant. The Beth Israel Deaconess Medical Center notes, however, that these negative reactions are hypothetical and no evidence as of 2011 exists to suggest this problem has actually occurred. Talk to your doctor before using any supplement if you are pregnant, breastfeeding or have liver or kidney disease.