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Shiitake Mushroom Benefits and Side Effects

7 min read
Shiitake mushroom benefits

Shiitake Mushroom Benefits and Side Effects

7 min read

Medically reviewed by

Did you know that shiitake mushrooms are adaptogens that have been used in traditional Chinese medicine for thousands of years to treat a variety of ailments? 

Or that they were considered a delicacy reserved for royalty in ancient Japan? 

Beyond their rich cultural history, the shiitake mushroom benefits are widespread, from boosting the immune system to potentially fighting cancer. 

However, as with any supplement or food, there are also possible side effects to be aware of. 

In this blog post, we’ll delve into the fascinating world of shiitake mushrooms, exploring:

  • The nutritional value of shiitake mushrooms
  • The health benefits of shiitake mushrooms
  • The side effects of shiitake mushrooms
  • How to take shiitake mushrooms

In this guide:

What is shiitake mushroom?

Shiitake mushrooms, scientifically known as Lentinula edodes, are a type of edible mushroom that originated in East Asia, particularly in Japan, Korea, and China. 

Shiitake has been cultivated and used for its culinary and medicinal properties for thousands of years.

Historically, shiitake mushrooms were considered a delicacy and were primarily consumed by royalty and nobles in ancient Japan. In Chinese medicine, shiitake mushrooms were used to treat a variety of ailments, such as respiratory infections, liver disease, and even baldness.

Shiitake mushrooms are known for their distinct umami flavour and meaty texture, making them a popular ingredient in many dishes around the world. They are also a rich source of nutrients, including B vitamins, copper, and selenium.

In addition to their culinary and medicinal uses, shiitake mushrooms have various cultural and spiritual meanings in different parts of the world. 

For example, in Chinese culture, they are associated with longevity and are considered a symbol of good luck. In Korean culture, they are often used in traditional rituals and ceremonies.

shiitake mushroom health benefits
Shiitake mushrooms have been used in traditional Chinese medicine for centuries.

What is the nutritional value of shiitake mushrooms?

Shiitake mushrooms are a nutritious food with a range of vitamins, minerals, and other beneficial compounds. They are a low-calorie, nutrient-dense food that can be a great addition to a healthy diet.

Here’s a breakdown of the nutritional value of shiitake mushrooms per 100 grams:

  • Calories: 34
  • Protein: 2.2 grams
  • Carbohydrates: 6.8 grams
  • Fibre: 2.5 grams
  • Fat: 0.5 grams
  • Vitamin B2 (riboflavin): 0.4 mg (31% of the daily value)
  • Vitamin B3 (niacin): 3.9 mg (25% of the daily value)
  • Vitamin B5 (pantothenic acid): 1.4 mg (28% of the daily value)
  • Vitamin B6 (pyridoxine): 0.1 mg (8% of the daily value)
  • Vitamin D: 18 international units (4% of the daily value)
  • Copper: 0.3 mg (33% of the daily value)
  • Selenium: 21.3 mcg (39% of the daily value)


Shiitake mushrooms also
contain various polysaccharides, including beta-glucans, which are known to support the immune system. Additionally, they are a good source of ergothioneine, a powerful antioxidant that may help protect against oxidative stress and inflammation.

What are shiitake mushroom health benefits?

As we’ve already stated, Shiitake mushrooms have been used for medicinal purposes for centuries, and recent research suggests they may have numerous health benefits. 

Let’s take a closer look at the potential health benefits of shiitake mushrooms.

Shiitake for immune system support

Shiitake mushrooms contain a variety of polysaccharides, including beta-glucans, that have been shown to stimulate the immune system. These compounds help activate immune cells, increase antibody production, and enhance the body’s ability to fight off infections and diseases.

Research suggests that regular consumption of shiitake mushrooms may increase the production of white blood cells, which can help fight off infections and disease

Additionally, shiitake mushrooms are a good source of antioxidants, which can also support immune function.

Shiitake may promote cardiovascular health

Shiitake mushrooms contain compounds that may help improve cardiovascular health, such as eritadenine, a type of amino acid that has been shown to help lower cholesterol levels. High levels of LDL (low-density lipoprotein) cholesterol, also known as “bad” cholesterol, are a risk factor for cardiovascular disease.

Additionally, shiitake mushrooms are a good source of dietary fibre, which can help lower cholesterol levels by binding to bile acids in the gut and preventing them from being reabsorbed into the bloodstream. This process forces the liver to use up more cholesterol to produce more bile acids, which can help reduce overall cholesterol levels in the blood.

Shiitake mushrooms are also rich in potassium, which is important for maintaining healthy blood pressure levels. Adequate potassium intake has been linked to a reduced risk of stroke and other cardiovascular events.

Moreover, shiitake mushrooms are a good source of antioxidants, including polyphenols and selenium, which may help protect against oxidative stress and inflammation. Chronic inflammation and oxidative stress are risk factors for cardiovascular disease and other chronic illnesses.

Shiitake may have anti-cancer properties 

Some studies suggest that shiitake mushrooms may have anti-cancer properties due to the presence of compounds like lentinan and beta-glucans. These compounds may help activate immune cells to attack cancer cells and have direct cytotoxic effects on cancer cells.

In addition, shiitake mushrooms are a good source of ergothioneine, an antioxidant that has been shown to have protective effects against oxidative stress and may help prevent DNA damage that can lead to cancer. 

Studies have also found that shiitake mushrooms contain other bioactive compounds, such as polysaccharides and polyphenols, that have anti-tumour effects and may help prevent the development and spread of cancer cells.

Shiitake for nutrients

Shiitake mushrooms are a good source of many vitamins, minerals, and other beneficial compounds. As mentioned earlier, they contain high levels of B vitamins, copper, selenium, and ergothioneine, all of which play important roles in maintaining overall health.

Health benefits of Shiitake mushrooms
Shiitake mushrooms may provide a host of health benefits, from immune system support to potential anti-cancer effects.

What are the side effects of shiitake mushrooms?

Shiitake mushrooms are generally safe for most people when consumed in moderate amounts as part of a healthy diet. However, some people may experience side effects or allergic reactions. 

Some potential side effects include:

  1. Skin sensitivity
    Handling shiitake mushrooms can cause skin sensitivity in some people. This is known as
    shiitake dermatitis and can cause a red, itchy rash.
  2. Vitamin D toxicity
    Shiitake mushrooms are a natural source of vitamin D, and consuming large amounts of them or taking vitamin D supplements can lead to vitamin D toxicity, which can cause nausea, vomiting, and weakness.
  3. Hypersensitivity pneumonitis
    This is a type of lung inflammation that can occur when a person inhales the spores of shiitake mushrooms. It is a rare but serious condition that can cause symptoms such as coughing, fever, and difficulty breathing.
  4. Headaches
    Some people have reported experiencing headaches after eating shiitake mushrooms. This may be due to the presence of a compound called guanosine monophosphate (GMP), which can cause vasodilation and increased blood flow to the brain.
  5. Immune system suppression
    Shiitake mushrooms contain a polysaccharide called lentinan, which has been shown to have immune system-suppressing effects in some animal studies. While this effect has not been definitively confirmed in humans, people with weakened immune systems should exercise caution when consuming large amounts of shiitake mushrooms or taking supplements containing lentinan.
  6. Increased risk of bleeding
    As mentioned earlier, shiitake mushrooms contain eritadenine, which can have blood-thinning effects. In addition to people taking blood-thinning medications, those with bleeding disorders or who are about to undergo surgery should also be cautious when consuming shiitake mushrooms.

How do I take shiitake mushrooms?

You can take shiitake mushrooms in a variety of ways, depending on your preference and the type of dish you are making. Here are some common ways to take shiitake mushrooms:

  1. Cooking
    Shiitake mushrooms can be sautéed, stir-fried, roasted, baked, or grilled. They are often used in Asian cuisine and can be added to soups, stews, rice dishes, and noodle dishes. They are also a popular ingredient in vegetarian and vegan recipes as a meat substitute.
  2. Tea
    Dried shiitake mushrooms can be steeped in hot water to make a flavorful tea. This is a common practice in traditional Chinese medicine, where
    shiitake tea is believed to have immune-boosting and anti-inflammatory properties.
  3. Supplements
    Shiitake mushroom supplements are available in capsule or powder form. They are often marketed for their immune-boosting properties and may contain concentrated amounts of lentinan or other active compounds.
  4. Broth
    Shiitake mushroom broth is a popular ingredient in vegan and vegetarian cuisine. It is made by simmering shiitake mushrooms in water with other vegetables and herbs to create a flavorful and nutrient-rich broth.


When buying shiitake mushrooms, look for fresh, firm mushrooms with no signs of mould or discolouration. If using dried shiitake mushrooms, soak them in hot water for 20-30 minutes before using them to rehydrate them. 

As with any new food or supplement, it is always a good idea to consult with a healthcare professional before incorporating shiitake mushrooms into your diet.

What are shiitake mushrooms
Shiitake mushrooms are delicious cooked, but can also be enjoyed in a tea or taken as a supplement.

Who should not take shiitake mushrooms?

  1. People with allergies
    If you have a known allergy to shiitake mushrooms or any other type of mushroom, you should avoid consuming them.
  2. People with autoimmune disorders
    Shiitake mushrooms contain compounds that can stimulate the immune system, which can be beneficial for most people. However, for individuals with autoimmune disorders such as lupus or rheumatoid arthritis, this immune-stimulating effect may exacerbate their condition.
  3. People taking certain medications
    As mentioned earlier, shiitake mushrooms contain eritadenine, which can have
    blood-thinning effects. If you are taking blood-thinning medications such as warfarin or aspirin, you should be cautious when consuming shiitake mushrooms or talk to your healthcare provider before adding them to your diet.
  4. People with bleeding disorders
    Similarly, if you have a bleeding disorder such as haemophilia or von Willebrand disease, you should be cautious when consuming shiitake mushrooms or talk to your healthcare provider before adding them to your diet.
  5. Pregnant or breastfeeding women
    There is limited research on the safety of shiitake mushrooms during pregnancy and breastfeeding, so it is best to avoid consuming them or consult with a healthcare provider before doing so.

Final words on shiitake mushrooms

Shiitake mushrooms have a rich cultural and medicinal history, and recent research has shown they offer numerous health benefits.

From boosting the immune system to potentially fighting cancer, these mushrooms are a great addition to any healthy diet. 

However, as with any supplement or food, it is important to be aware of potential side effects. It is also essential to consult with a healthcare professional before incorporating shiitake mushrooms into your diet, especially if you have any underlying health conditions. 

Overall, shiitake mushrooms are a tasty and nutritious food that can provide a range of health benefits when consumed as part of a balanced diet.

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