Health Benefits and Side Effects of Shiitake Mushroom Supplements

Shiitake mushrooms are an edible fungus commonly eaten in many Asian dishes. Although it might not seem like it, Shiitake is actually a functional mushroom that presents many similar benefits akin to Reishi or Lion's Mane and can be bought in the form of vegan or vegetarian supplements. What benefits do they have, exactly, and what potential side effects are there?

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Side Effects of Shiitake Mushroom Supplements

Although rare, continuous consumption of natural Shiitake mushroom supplements can lead to certain adverse reactions.

A study published by the National Library of Medicine found that constant consumption of powdered Shiitake mushroom extract caused gastrointestinal problems, abdominal pains, and rashes (Shiitake dermatitis). It was later discovered that the reason for this was a condition called eosinophilia.

Eosinophils are a type of white blood cell that is involved in immune responses to various allergic reactions, cancers, and parasites. Although not necessarily bad on their own, their job is to defend the body and then disappear. Markedly high levels of eosinophils for a long period of time is called eosinophilia and can lead to further complications like chronic inflammation and damaged tissues.

What this suggests is that either some of our bodies perceive Shiitake mushrooms as dangerous, or that the participants of the study had mushroom allergies. The good news is that all adverse reactions halted after the participants stopped taking the Shiitake powder.











Health Benefits of Shiitake Mushroom Supplements

Health and Longevity

This point is specifically due to the potential boost in the immune system that Shiitake mushrooms cause. This study on mice found that Shiitake aided in immune support and cancelled out the degenerative effects caused by aging.

Additionally, another study found that many types of functional mushrooms (Shiitake included) possessed anti-viral and antibacterial properties that were effective at combating various diseases, suggesting that they could potentially be an answer to antibiotic-resistant bacteria.

Furthermore, the polysaccharide content of Shiitake mushrooms is thought to improve cognitive brain health by boosting memory and combating symptoms of Alzheimer's and dementia.

Improved Circulation and Heart Health

There are many factors that contribute to an overall healthy circulatory system. One of those is healthy levels of cholesterol as too much unhealthy LDL cholesterol can "clog" your arteries, increase blood pressure, and affect your circulation. This study found that Shiitake-fed rats had reportedly lower levels of cholesterol.

Additionally, this study found that the beta-glucan content of Shiitake mushrooms was effective at alleviating hypertension and contributing to improved heart health.

Shiitake May Have Anti-Cancer Properties

Like many functional mushrooms, Shiitake mushrooms are believed to possess anti-tumour properties in certain cancers, as suggested by this study. Additionally, like some other functional mushrooms, Shiitake has been observed to activate the cytotoxic immune response against certain cancers and potentially enhance the efficacy of other cancer treatments. However, there isn't enough conclusive evidence to confirm or deny this outright.

Vitamin D Content

Like all mushrooms, Shiitake has high levels of vitamin D, which could contribute to healthier bones. Additionally, vitamin D is important for "anti-inflammatory, antioxidant and neuroprotective properties [that] support immune health, muscle function, and brain cell activity."(1)

Are Shiitake Mushrooms Healthy and Nutritious?

Eating Shiitake mushrooms promises the same nutritional profile as most other edible mushrooms, specifically, one cup of cooked Shiitake mushrooms contains:

• Low calories (Around 81), which means that Shiitake mushrooms can be good for weight loss.
• Low fat (0.3g)
• 21g Carbohydrates, of which around 5g is natural sugars and 3g is dietary fibre.
• 2.3g protein.

Other than this, Shiitake mushrooms contain a number of beneficial vitamins and minerals like copper. In short: Yes, Shiitake mushrooms are good for you.

Are Some People More Affected By Shiitake Than Others?

Since Shiitake mushrooms are a type of fungus, individuals with a mould or mushroom allergy will likely suffer a Shiitake mushroom intolerance as well. Additionally, most of the side effects experienced from Shiitake mushrooms are thought to occur as a result of consuming raw, uncooked shiitake mushrooms.

If you are unsure of your own predispositions and potential allergies, consult with a doctor before implementing Shiitake (or any other functional mushroom) into your diet.