Beta Glucan and Cancer
What are Beta Glucans?
Beta glucans are naturally occurring fibers made up of polysaccharides (multiple sugars joined together). These chains of glucose molecules are principle constituents of the cell walls of certain microorganisms like bacteria, yeasts, and fungi. Polysaccharides are biologically active, meaning they can carry biological data through their branch-like structures. Each source has its own molecular shape and exhibits different health benefits based on its shape. Depending on the length and position of the beta glucan structure, it may be referred to as beta 1,3 (or beta 1,3D) glucan, beta 1,4 glucan or beta 1,6 glucan.
Sources of Beta Glucans
Beta glucans do not occur naturally within the human body and are not synthesized by the body. Therefore, they need to be consumed from food sources or nutritional supplements. Excellent sources of beta glucans include fermented foods, medicinal mushrooms (reishi, shiitake, maitake), yeasts, seaweed, and algae. Beta glucans are also found in the bran of many common whole grains, with oats and barley containing the highest amounts. Although beta 1,3 glucan is a natural extract of baker’s yeast (an allergen for many people), most beta glucan supplements contain a very minimal amount of yeast proteins and are thus unlikely to cause an allergic reaction.
Benefits of Beta Glucans
More than 1,000 scientific articles have been published over a span of 50 years demonstrating the many biological benefits of beta glucans, especially a response system known as immuno-modulation. However, while grain-derived beta glucans are valuable for our health in terms of lowering cholesterol and inflammation, they have been shown to be ineffective as immune modulators.
In contrast, yeast-derived beta glucan exhibits remarkable ability to prime immune cells, effectively stimulating immune responses from T-cells, natural killer (NK cells), cytokines, interleukin (IL) 1 and 2, macrophages and antibodies, and helping them to execute a well-coordinated attack on their targets.
According to a 2008 article published in Mutation Research/Reviews in Mutation Research, beta glucan polysaccharides “stimulate the immune system… and thereby have beneficial effect in fighting infections (bacterial, viral, fungal and parasitic). β-Glucans also exhibit hypocholesterolemic and anticoagulant properties [and] have been demonstrated to be anti-cytotoxic, antimutagenic and anti-tumorogenic, making them promising candidates as pharmacological promoters of health.”
Beta Glucans and Cancer
Research has proven the ability of beta glucans to fight cancer. First, by protecting against toxic carcinogens, they can prevent oncogenesis. During the promotional stage of cancer, beta glucans work to mobilize cancer-fighting molecules inside the body, especially NK cells, which are crucial to inhibiting cancer growth. Another way in which beta glucans work is through anti-angiogenesis (interference with a tumor’s blood supply) to reduce cancer proliferation and prevent metastasis.
Beta glucans also stimulate various cells within the body to unleash anti-cancer molecules. These molecules include interleukins 1 and 6, hydrogen peroxide, gamma interferon, and tumor necrosis factor, all of which have been shown to antagonize cancer.
The ability of 1,3 beta glucan to inhibit tumor growth has been well established for about 40 years in a variety of experimental tumor models. Beta glucans have been used as adjunctive therapy for cancerous tumors since 1980, according to Comprehensive Reviews in Food Science and Food Safety (June 2012). Because of their role in the restoration of compromised bone marrow function, beta glucans are considered an excellent adjuvant to chemotherapy and radiation therapy.
A large collection of research data demonstrates that beta glucans provide measurable anticancer activity in terms of tumor growth, tumor volume, degree of metastases, and /or survival. Most of the studies on the antitumor properties of beta glucan were conducted in Japan with various types of mushrooms and fungi, but one study with oat beta glucan found significant macrophage anticancer activity and significant ability (along with short-term exercise) to inhibit the metastatic spread of injected melanoma cells.
Science has also shown that orally administered beta-glucan can exert an adjuvant effect against a broad range of cancers when used with monoclonal antibodies. Multinational research has demonstrated that the oral ingestion of beta 1,3-D glucan has similar protective effects as the injected version, including defense against infectious diseases and cancer. Although most of these studies have been conducted with animals, at least a few studies confirm the value of beta glucans for cancer treatment in humans.
A study published in Molecular Urology in 2000 on human prostate cancer found that beta glucan from the maitake mushroom produced a cytotoxic (cancer cell-killing) effect through apoptosis (cancer cell suicide) in human prostatic cancer cells. The researchers concluded that “this unique mushroom polysaccharide may have great a potential as an alternative therapeutic modality for prostate cancer.”
Another study of beta glucan published in the International Immunopharmacology in 2007 compared 23 female patients with advanced breast cancer (median age 52 years) and 16 healthy females. It was concluded that oral beta glucan administration seems to stimulate proliferation and activation of white blood cells known as monocytes in patients with advanced breast cancer.
Yeast is often considered "the mother of all beta glucans" for its immune system support. Soluble fibers from barley and oats provide anti-inflammatory effects through their beta glucan content, but studies show that the highest levels of biological response and immunomodulation are attained with insoluble beta glucans. Insoluble beta glucans are found in Saccharomyces boulardii (a tropical species of yeast), brewer’s yeast (Saccharomyces cerevisiae), as well as medicinal mushrooms like maitake and reishi.
When supplementing with beta glucans, recommended daily dosages range from 5 to 10 mg per pound of body weight. If you weigh 150 pounds, the dose would therefore be 750-1500 mg per day, best taken between meals 500 mg at a time. Most manufacturers of beta glucan supplements suggest doses of 1,000 mg daily to achieve effective results.
Beta glucan is one of the safest therapies available for providing immune-stimulating and cancer-fighting properties. Compared with conventional medical therapies, beta glucans are an affordable and safe option for preventing and healing cancer while posing no adverse health reactions.
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 Demir G, Klein HO, Mandel-Molinas N, and Tuzuner N. Beta glucan induces proliferation and activation of monocytes in peripheral blood of patients with advanced breast cancer. International Immunopharmacology, Volume 7, Issue 1, January 2007, 113–116 http://www.sciencedirect.com/science/article/pii/S1567576906002566
 Daou C and Zhang H.Oat beta-glucan: Its role in health promotion and prevention of diseases. Comprehensive Reviews in Food Science and Food Safety. 12 June 2012.
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 Hong F, Yan J, Baran JT, Allendorf DJ, Hansen RD, Ostroff GR, Xing PX, Cheung NK, Ross GD. 2004. Mechanism by which orally administered β-(1, 3)-glucans enhance the tumoricidal activity of antitumor monoclonal antibodies in murine tumor models. J Immunol 173(2):797–806.
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 Mantovani MS, Bellini MF, Angeli JP, Oliveira RJ, Silva AF and Ribeiro LR. β-Glucans in promoting health: Prevention against mutation and cancer. Mutation Research/Reviews in Mutation Research. Volume 658, Issue 3, March–April 2008, 154–161. http://www.sciencedirect.com/science/article/pii/S1383574207000269