Everyone gets a cold now and then, but keeping a strong immune system year-round will help fight off those sick days. Luckily, the natural products marketplace can help with products like mushrooms and herbs.
Glucan Gladiators
Beta-glucans, a type of polysaccharide, are featured in a great number of research trials on numerous aspects of immune health. Used as traditional medicines, mushrooms are loaded with certain beta-glucans and have become quite a group of immunomodulating natural products, supported by a wealth of research.
Eight mushroom strains were tested in a Dutch study for their immunomodulating capabilities, and the extracts of Ganoderma lucidum (reishi) and Volvariella volvacea were found to act directly on monocytes to modulate T cell activation.1 Further studies on reishi suggest its polysaccharides prompt splenic B cell activation and enhance antibody secretion, specifically stimulating TNF-alpha and IL-6 production, and IFN-gamma release.2,3
One of the most popular mushroom extracts is Grifola frondosa or maitake. A proprietary extract of maitake—D-Fraction, from Maitake Products—appears to activate immune cells including macrophages, dendritic cells (immune cells that process antigens) and T cells, in addition to supporting the cytotoxicity of NK cells.4,5,6 In vitro tests on a hot water extract of maitake mycelia showed strong cytokine activity and enhanced up-regulation of certain neutrophils in a dose-dependent manner.7
John Seleen, president of JHS Natural Products, stressed the importance of hot water extraction for mushroom beta-glucans. "Hot water extraction allows you to concentrate active compounds to a level many times higher than what you find in non-extracted mushroom product," he explained, noting most extracts in Traditional Chinese Medicine (TCM) are at least 4:1 (kilos of dry herb to kilos of finished extract) with hot water extracts as high as 20:1 polysaccharide content. "Alcohol can penetrate the cellulose fibers of other plants and draw out actives, but it can't penetrate the mushroom cell walls, which are made from chitin—the same material comprising lobster shells.”
In his book, "The Health Benefits of Medicinal Mushrooms," Mark Stengler, N.D., wrote: "The majority of published scientific literature that I was able to locate on the clinical effects and health benefits of using medicinal mushrooms used supplements prepared with hot-water extraction. This is also consistent with the references on traditional use by East Asian herbalists."
According to Seleen, Coriolus versicolor is one of the most researched mushrooms in immune health. In fact, Japanese researchers reported protein-bound polysaccharide-K (PSK) found in this species has both cellular and humoral immunomodulatory effects, including enhanced IgM production and B cell activity, as well as antibody production.8 This mushroom has also been shown to activate CD4+ T cell response in the lymph nodes and modulate T cell receptor-induced IL-2 production.9
Another popular mushroom for immune support is Agaricus blazeii Murill, which is attributed with strong immunomodulating properties.10 Research has found this species can increase IgG and T cell counts in the spleen, in addition to elevating both phagocytic capability and the body’s resistance to bacterial infection.11 In cancer patients, A. blazeii administration has increased NK cell activity and improved chemotherapy-associated side effects.12
Combining mycelia (vegetative structure of fungi) from several medicinal mushrooms, Active Hexose Correlated Compound (AHCC®, manufactured by Amino Up Chemical Co., U.S. distribution by Maypro Industries), has been shown to modulate immunity and increase survival in response to acute infection and has been tested against a variety of infectious agents.13 According to animal studies, AHCC can regulate adaptive and innate immune response, enhancing the body’s tumor surveillance and increasing its response rate to pathogenic infection 14,15 A recent Japanese trial found healthy adults taking AHCC for four weeks had increased dendritic cell levels and differentiation.34 A similar trial revealed 60 days of AHCC supplementation could increase levels of the cytokines INF-gamma and TNF-alpha, enhancing the T cell immune response.16
Polysaccharide beta-glucans also can be found and sourced in certain yeasts. A proprietary 1,3/1,6 glucan (Wellmune WGP®, from Biothera) derived from the cell walls of the yeast Saccharomyces cerevisiae has undergone many studies on its immune-enhancing effects. A single blind, crossover study on the effects of Wellmune WGP® on upper respiratory tract infections (URTIs) in firefighters—the stress of their job can depress immunity—reduced incidence of infections after a 14-day intervention period.17 These results on respiratory infection were duplicated in studies on other subjects under stress, including marathon runners (exercise saps the immune system). Similarly, a trial in healthy adults found those taking Wellmune WGP for 90 days had shorter and less severe colds than the placebo group.18
Another proprietary Saccharomyces cerevisiae ingredient is EpiCor®, from Embria Health Sciences, a dried, complex fermentation product from the yeast and its medium, yielding a high-metabolite immunogen. In two trials conducted in early 2007, active intervention with 500 mg/d EpiCor in adults who received flu vaccination significantly reduced the incidence of URTIs and the duration of symptoms in subjects who did get URTIs.
Additional research has shown 500 mg/d of EpiCor can also increase levels of secretory immunoglobin A (sIgA) and modulate levels of IgE. In a recent trial conducted by NIS Labs for Embria, 500 mg/d of EpiCor or placebo for five weeks in healthy adults resulted in increased levels of hematocrit and sIgA, as well as decreases in serum IgE and IL-10. The researchers concluded EpiCor supported the health of red blood cells and mucosal immune protection and may exert beneficial anti-inflammatory effects in situations of chronic inflammation or allergies.