Mushrooms Help Fight Colds and Flu

Beta glucans, compounds found in mushroom cell walls,¹ can strengthen immune defenses against viruses and other harmful agents,³ while guarding against overactive immune responses.⁴

Beta glucans reduced upper respiratory symptoms like runny nose and sore throat by as much as 58% in human studies.^5,6

In separate clinical trials, mushrooms⁷ and isolated beta glucans substantially boosted IgA (immunoglobulin A)^,8 an antibody that defends against viral infections.

Combining mushroom extracts with beta glucans from yeast may optimize immune function to protect against colds and flu.

Balancing Immune Function

An underactive immune system increases susceptibility to infections like colds and flu and certain diseases like cancer.^9,10

An overactive immune system can contribute to recurrent or chronic immune-mediated diseases such as allergies and autoimmune disorders.¹¹

Beta glucans are a type of fiber found in mushrooms and other fungi that can stimulate and help regulate the body’s immune cell activity.^3,12

Beta glucans activate cells involved in the two major types of immune responses:

• Innate immunity, the body’s first, general line of defense against viruses and other pathogens,^13,14 and
• Adaptive immunity, a longer-term, targeted immune response against a specific pathogen.^13,15

Some of their immune benefits come from how they interact with the gut microbiome, an immune system regulator.^16-18 Because beta glucans are indigestible fiber, they serve as prebiotics that nourish beneficial bacteria.¹⁹

Beta glucans also have anti-inflammatory effects.¹

Two top sources of beta glucans are the cell walls of baker’s yeast and specific species of mushrooms.^20,21

Shiitake Primes Immune Cells

Shiitake is a mushroom source of beta glucans.^20,22,23

Cell studies show that shiitake extract can inactivate some viruses and stop them from replicating.^24,25

In a clinical trial of healthy adults, daily intake of dried shiitake mushrooms for four weeks:⁷

• Increased salivary IgA, which protects against upper respiratory infections, by 12%,
• Reduced C-reactive protein (CRP), a marker of harmful chronic inflammation, by 30%,⁷ and
• Increased the number of specific innate immune cells by 60% to 100% and boosted the robustness of their defense.⁷

Certain components of shiitake, particularly beta glucans, prime innate immune cells to be ready for harmful intruders.²⁶

Mushroom Synergy

Two other types of mushrooms, maitake,^27,28 and chaga,^29,30 have also been shown to aid the immune system. They are both high in beta glucans and antioxidants.

In an analysis of medicinal mushroom extracts, chaga ranked highest in anti-oxidant activity, followed by maitake.³¹

Preclinical research has shown that compounds in chaga mushrooms have strong antiviral activity, including against influenza.^30,32

Combining different types of mushrooms may synergistically enhance their immune system benefits.³³

In an animal model, the combination of maitake and shiitake extracts more strongly activated innate immune defenses than either mushroom alone.²⁸

Beta Glucans Fight Infections

Mushrooms have many beneficial compounds, but beta glucans are believed to be the most central to viral defense. They are found in mushrooms and can also be isolated from yeast.

In an initial human study, researchers gave beta glucans to healthy adults daily for three months during peak cold and flu season.³⁴

The treatment group developed significantly fewer fevers than the placebo group.

None of the treatment group missed work or school due to colds, while placebo recipients missed an average of 1.4 days.

The immune benefits of beta glucans have been further confirmed in many clinical trials.^3,21

Its effects are especially remarkable in those more susceptible to upper respiratory infections, including older adults and people who are mentally or physically stressed.^3,6,35-37

What You Need To Know

Fungi Fight Immune Challenges

• Shiitake, maitake, and chaga mushrooms contain compounds called beta glucans, which support healthy immunity and help defend against viruses like colds and flu.
• In clinical trials, beta glucans from yeast reduced upper respiratory symptoms like runny nose and sore throat by as much as 58% and reduced the severity of seasonal allergy symptoms by 52%.
• A blend of shiitake, maitake, and chaga mushroom extracts with beta glucans from yeast can provide substantial immune system support and reduce the impact of colds and flu.

In clinical trials:

• Middle-aged to older adults taking 250 mg of yeast beta glucans daily during winter had fewer colds and flu and a shorter duration of symptoms than placebo recipients.³⁷
• Moderately stressed women who took 250 mg of beta glucans daily for three months had a 58% reduction in upper respiratory symptoms compared to a placebo.⁶
• Runners who took 250 mg of beta glucans daily for 28 days after running a marathon (a stressor which can suppress immunity) had a 37% reduction in the number of days with cold or flu symptoms compared to placebo recipients.⁸
• Moderately active adults taking 250 mg of yeast beta glucans for 10 days had a 32% increase in immune-protective salivary IgA two hours after a strenuous exercise test, compared to a placebo.⁸

A systematic review and meta-analysis of 13 random- ized controlled trials found that yeast beta glucans significantly lowered the risk of upper respiratory tract infections in healthy people.

Compared to placebo, beta-glucan supplementation reduced the likelihood of developing an upper respiratory tract infection by 34%, decreased the number and duration of episodes by 31%, and often improved symptom severity.²¹

Other Immune Effects

Infections aren’t the only immune system threat.

Allergies can also arise from a dysfunctional immune system.

In a clinical trial, adults with moderate ragweed allergies were given 250 mg of beta glucans from yeast every day for a month during allergy season.⁵

Compared with a placebo, the treatment group had a 28% reduction in the number of allergy symptoms and a 52% reduction in symptom severity, including nasal and eye symptoms.⁵

Combining mushroom extracts and beta glucans may provide comprehensive immune support.

Summary

Shiitake, maitake, and chaga mushrooms contain beta glucans, compounds that support the immune system.

More than a dozen clinical trials have shown that beta glucans help bolster immune defenses against upper respiratory infections like colds and flu.

Beta glucans can also help calm overactive immune responses that lead to allergy symptoms.

A combination of mushroom extracts and beta glucans isolated from baker’s yeast may optimize immune system function and help ward off upper respiratory infections. n

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.

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