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How An Immunologist Uses Mushrooms To Help Fight The Cold & Flu

Heather Moday, M.D.
December 8, 2019
Heather Moday, M.D.
Allergist & Immunologist
By Heather Moday, M.D.
Allergist & Immunologist
Heather Moday, M.D. is the founder of the Moday Center for Functional and Integrative Medicine in Philadelphia, where she practices both traditional medicine and integrative medicine.
December 8, 2019

Medicinal mushrooms are everywhere these days, from tinctures and pills to coffee and moisturizers. While they're definitely having a moment, mushrooms are nothing new; many have been used in ancient medicine for millennia. There are thousands of species of mushrooms, and their purported benefits range from supporting liver and heart health to enhancing energy and more.

One of the most potent effects of many medicinal mushrooms is their strong antiviral and immune-enhancing properties. Several mushrooms, in fact, have been shown to be effective against preventing and treating respiratory viruses like the common cold and even the flu virus, which is impressive considering the highly infectious nature of viruses and that they are notoriously difficult to prevent and treat due to their ability to easily mutate. Not all antivirals work the same with all conditions though; for example, there is some evidence that mushrooms might be harmful when treating the novel coronavirus, so check in with your health care provider if you have symptoms. 

How do mushrooms help our immune system?

Mushrooms themselves need antibacterial and antiviral compounds to survive in the wild, so they naturally harbor a lot of these substances. 

They have powerful constituents called beta-D-glucans, beta-glycosides, and other substances that have been determined in some research to significantly stimulate our innate immune system1. Some mushrooms are a rich source of selenium, magnesium, and zinc1, all of which may play a direct or indirect role in their anti-influenza properties. Research is still emerging about the power of mushrooms, but some studies show their promise—and considering that they can be added to soups, stews, sauces, and more, they couldn't be easier to incorporate into your diet.

These are four mushrooms I always reach for to boost immunity.

4 fungi that can help fight the cold and flu:


Maitake (Hen-of-the-Woods)

This delicious edible mushroom is one of my favorites not only because it's so tasty, but because it has some broad-ranging health properties. 

In a Japanese study, maitake mushroom extract was found to significantly inhibit the influenza A virus from replicating, and it stimulated the production of antiviral cytokines such as TNF-alpha. Interestingly, it was made even more powerful2 when combined with shiitake mushroom extract. Both shiitake and maitake are edible mushrooms that can easily be added to our diet, but they can also be found in tincture and dried capsule form.



Shiitake mushrooms are an Asian culinary staple and easy to find in supermarkets. Whole shiitake, as well as its purified fractions, have been shown to have antiviral activities3 against the hepatitis C virus, herpes simplex virus, and human immunodeficiency virus as well as influenza.

When specifically studied on influenza, shiitake was found to inhibit the growth of the virus3 by preventing the entry and uncoating process of viral infection. Researchers also tested an intranasal vaccine3 of shiitake extract, which increased the survival of flu-infected mice. The best way to get the benefits of shiitake is to eat them, but they can also be found in medicinal mushroom blends in tinctures and dried products.


Reishi mushrooms

Another antiviral powerhouse fungus is the woody, and therefore inedible, reishi mushroom. Reishi has been recognized as a medicinal mushroom for thousands of years. Reishi has the ability to combat many viruses, such as herpes, Epstein-Barr, and hepatitis. It has also been found to be effective in killing influenza A virus4, which causes many outbreaks of flu throughout the season, including the very virulent and dangerous H1N1 strain5 of flu. 

Substances called triterpenes are one of the main beneficial compounds in reishi alongside the beta-glucans. Triterpenes are very bitter-tasting, making reishi rather inedible. But just because you can't throw it in your stir-fry doesn't mean that you should avoid it. You can typically find reishi in capsule, powder, and tincture form.



Although cordyceps mushrooms are technically not a mushroom but a parasitic fungus6, they have been touted as a "cure-all" in many ancient cultures. Cordyceps are known for being antifungal and antibacterial, as well as improving fatigue and libido. Originally cordyceps were only grown in the high altitude Himalayan mountains as a fungus that invaded certain caterpillars. However, they are now cultivated in the United States using different techniques.

The anti-influenza effect of cordyceps6 extract is thought to be driven by increased natural killer cell activity along with other virus-killing cytokines. In addition, cordyceps have been shown to improve lung health7 by decreasing inflammation in both chronic asthma and other lung diseases. It has been shown to improve exercise tolerance8 in athletes when used both acutely and chronically. This may be because they increase blood flow, enhancing oxygen use and acting as an antioxidant. So they are great to use both when sick or just when working out. Because cordyceps is not grown for culinary purposes, you will find them in pills, tinctures, and powders. 

How to choose the best mushroom products.

One caveat of medicinal mushrooms, as with all supplements, is that quality and efficacy can vary across products. 

When evaluating a mushroom product, make sure that it is organically grown and verified. In addition, if it's a tincture, tea, powder, or capsule, ask if the company does any third-party testing for purity, and make sure that they do not use any fillers. This will allow for the best quality, safety, and efficacy.

The bottom line.

There are many ways to add mushroom medicine into your life. Mushrooms are best used as a preventive measure to encourage immuno-stimulation against viruses and for their other wide-ranging benefits.

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Heather Moday, M.D. author page.
Heather Moday, M.D.
Allergist & Immunologist

Dr. Heather Moday received her medical degree from Tulane Medical School in New Orleans. She completed a residency in internal medicine and a fellowship in allergy and immunology. She completed a fellowship in integrative medicine with the Arizona Integrative Medicine program and is board-certified in integrative and holistic medicine. She completed her functional medicine training with the Institute for Functional Medicine and the Kalish Functional Medicine Fellowship.

She started the Moday Center for Functional and Integrative Medicine in Philadelphia, where she practices both traditional medicine and integrative medicine. You can learn more about Dr. Moday through her blog and website and follow her on her YouTube channel, Functional Medicine TV.