Shiitake mushroom: benefits, uses and side effects

What is shiitake mushroom?

Shiitake is quite unique among medicinal mushrooms in that people prize it for both its flavour and its health benefits. Thanks to its earthy umami taste and firm, almost meaty texture, it’s one of the world’s most popular edible fungi. In addition to eating fresh shiitake, you can consume it in dried, powdered or supplement form.

Although now cultivated around the world, shiitake is native to East Asia. In the wild, it naturally grows on hardwood logs – particularly the Japanese shii tree from which it gets its name. The Latin term for the mushroom is Lentinula edodes, but it’s also referred to as black mushroom and golden oak mushroom.

Despite these names, shiitake is actually more of a brown hue. It has a tough stem topped with an umbrella-like cap that’s usually between 5-10 centimetres wide. There are several different types of shiitake mushroom, with the main varieties being koshin (fragrant) and donko (winter). Koshin mushrooms are more mature, with a larger cap and stronger aroma. Donko, on the other hand, are premium grade mushrooms that have smaller, denser caps marked with white cracks.

Practitioners of traditional medicine systems have been using shiitake for centuries. For example, in China people harnessed it to boost their Qi (life force), circulation, longevity, and overall health. Excitingly, modern scientific research is now finding evidence to back up some of these reported shiitake mushroom benefits. So, let’s take a closer look at how this fabulous fungus can enhance your wellbeing.

How shiitake mushroom benefits your immune system

One of the most notable reasons shiitake mushroom benefits your health is that it could strengthen your immunity. For instance, research has found that consuming the fungus can improve the function of immune cells and decrease inflammation.(1) The latter is important for wellbeing because chronic inflammation contributes to a number of medical conditions, from arthritis to Alzheimer’s.(2)

According to animal studies, shiitake may also be able to reduce or even reverse some age-related decline in immune function.(3) However, further evidence is required to confirm whether these specific shiitake mushroom benefits apply to humans.

Experts believe shiitake’s immunity-boosting effect is thanks to certain polysaccharides that the fungus contains, like beta-glucans. These can enhance the activity of particular types of immune cells, such as macrophages and natural killer cells.(4) Moreover, shiitake is a fantastic source of copper, and this mineral is vital for maintaining optimal immune function.

In addition, polysaccharides may further support immunity by acting as a prebiotic. This means they stimulate the growth of good bacteria in your digestive system, improving the health of your gut microbiome. This is key because both the condition of your gut and the type of bacteria that live there affect the strength of your immune system.(5) The fact shiitake is high in fibre bolsters this effect, as fibre further helps to keep your digestive system healthy.

In line with its positive influence on immunity, scientists are additionally investigating the antimicrobial, antifungal, and antiviral properties of shiitake.(6) It’s possible that compounds from the fungus could help us fight infections, although more research is necessary to clarify this.

Shiitake’s anti-cancer properties

Among the most exciting shiitake mushroom benefits is the fungus’s potential to combat cancer. In particular, one of the polysaccharides it contains – called lentinan – shows a lot of promise in this area. Research has found that it can help to fight tumours, plus inhibit the growth and spread of leukaemia cells.(7) This is partly through shiitake’s ability to activate the immune system, as we discussed above.

Interestingly, studies also demonstrate that using lentinan alongside chemotherapy helps prolong survival and improve quality of life for cancer patients.(8) However, further research is required to ascertain how beneficial fresh or powdered shiitake might be with regard to cancer.

How shiitake mushroom benefits cardiovascular health

Another of the main shiitake mushroom benefits is the positive impact it can have on the health of your heart. There are several reasons for this.

Firstly, shiitake contains numerous compounds that help to lower your levels of cholesterol.(9) These include eritadenine, which reduces cholesterol in the blood, and beta-glucans. The latter may decrease the amount of cholesterol absorbed by the intestines. All of this is important because high cholesterol can clog the arteries and lead to the development of heart disease.

Evidence also suggests that consuming shiitake could help to reduce your blood pressure.(10) This could be thanks to the potassium it contains, which works to relax blood vessels. However, further research is required to confirm this.

Moreover, shiitake mushrooms could help to give you an energy boost. One reason for this is that they’re naturally high in B vitamins such as riboflavin (B2) and niacin (B3). Both are essential for our bodies to produce energy, and fatigue is a common symptom of a deficiency in B vitamins.

Shiitake mushroom benefits: nutrition

Mushrooms such as shiitake are of particular benefit to those who are following a plant-based diet. That’s because they’re one of the few non-animal sources of vitamin D. This nutrient is crucial for building and maintaining strong and healthy bones. The most effective varieties are mushrooms that are grown in sunlight or exposed to UV light.(11)

Shiitake is also a rich source of essential amino acids, including valine, lysine, and threonine. These are crucial for everything from muscle development to hormone production. The body can’t make essential amino acids by itself, so we need to acquire them from our diet. On top of which, the fungus is high in key minerals such as selenium, copper, and zinc.

Other notable shiitake mushroom benefits

Another way shiitake mushroom benefits our health is through its antioxidant properties.(12) The fungus contains potent triterpenoids such as ergothioneine, as well as phenolic compounds like gallic acid and catechin. These can help protect our cells against oxidative stress caused by free radicals. This is key because research has linked oxidative stress to several medical conditions, including Parkinson’s, cancer, arthritis, and cardiovascular disease. It can even speed up the rate of ageing – something we all want to avoid!

Finally, like many medicinal mushrooms, shiitake is an adaptogen. That means it might enable our bodies to cope with all kinds of stress more successfully, from physical to emotional. However, more study is necessary to discover how effective shiitake is in this regard.

Related reading

• How to make mushroom tea
• What are beta-glucans?

How to enjoy these shiitake mushroom benefits

As you can see, there are a wealth of potential ways in which shiitake mushroom benefits your health. So, the next question is how to harness them.

You have a few options when it comes to how to take shiitake. First, you’re able to use fresh or dried mushrooms. Unlike most other medicinal mushrooms, it’s fairly easy to get hold of shiitake in the supermarket. Their rich and earthy umami flavour goes brilliantly in all sorts of dishes, from stews to stir-fries.

If you’re using fresh shiitake, remove the stems first as they tend to be quite tough and take more time to cook. Meanwhile, dried shiitake is a brilliant choice when you want a more intense flavour. Conveniently, it also has a longer shelf life. Just remember to soak the dried mushrooms in hot water before cooking to rehydrate them.

Of course, you probably don’t want to eat shiitake mushrooms every single day! Or perhaps you don’t like the taste or texture of fresh mushrooms at all. That’s why taking shiitake in powder form can be a handy alternative. It’s also more versatile, as you’re able to add powder to a whole range of drinks and dishes.

We create our shiitake powder by drying the mushrooms and then grinding them. This means you get all the same nutrients as you would from eating fresh or dried mushrooms. They’re simply in a more concentrated form. As such, using powder is an effective way to enjoy the shiitake mushroom benefits we talked about above.

How to use shiitake mushroom powder

If you’d like to enjoy your shiitake mushroom benefits the traditional way, try using the powder to make mushroom tea. Simply stir half a teaspoon into a cup of hot – but not boiling – water, then let it steep for a few minutes. The warm liquid helps to draw out the nutrients, making this a very effective method of consuming shiitake powder.

Not all the powder will fully dissolve, so you can always pop it into a teabag first. This allows the mushroom to infuse into the water, while ensuring you enjoy a smooth drink. Be aware that mushroom tea can be a bit of an acquired taste! As such, you might like to include honey, ginger, lemon or other ingredients to balance out the shiitake.

To get your shiitake mushroom benefits in a more modern style, add shiitake powder to your favourite hot drinks instead. For instance, mushroom coffee is a fantastic way to start your day. Plus, the two flavours complement each other surprisingly well.

Alternatively, treat yourself to a luxurious, silky-smooth mushroom hot chocolate. Cocoa pairs perfectly with shiitake, masking the astringency of the fungus in a delicious blend of sweet and savoury notes. In addition, both coffee and cacao bring their own amazing health benefits to the mix. That makes these shiitake-enhanced beverages especially good for your wellbeing!

Naturally, you can also gain these shiitake mushroom benefits by using the powder in your cooking. We recommend adding about a teaspoon to recipes involving hot liquid, such as soups, stews, and risottos. This will ensure the nutrients get extracted from the powder. Because shiitake has a rich umami taste, it tends to go best in savoury dishes. Feel free to experiment and see which meals you enjoy it in the most!

Shiitake mushroom side effects and safe usage

In addition to knowing about shiitake mushroom benefits and ways to use the powder, it’s important to understand how to take it safely. Experts widely consider the fungus to be safe for human consumption. However, it’s best to avoid it if you have a mushroom allergy.

Similarly, you shouldn’t take any type of medicinal mushroom if you are pregnant or breastfeeding. This is simply because there is not enough research to determine whether it is suitable for these groups. Likewise, medicinal mushrooms should not be given to children.

Finally, if you’re on medication or have an existing medical condition, speak to a doctor before taking medicinal mushrooms. This will help to make sure you don’t experience any unwanted interactions.

When it comes to possible shiitake mushroom side effects, there are a couple to be aware of. Firstly, in rare cases, it’s possible to develop a skin rash after touching or eating raw shiitake mushrooms.(13) So to be on the safe side, always cook them properly.

In terms of shiitake powder, some old studies found that prolonged use and large doses may result in side effects. These include sensitivity to sunlight, blood abnormalities, and digestive problems.(14) Such experiences are rare, but if you notice any adverse reactions, it’s best to stop taking shiitake immediately.

The importance of quality in medicinal mushrooms

To enjoy the shiitake mushroom benefits discussed in this article, it’s crucial to choose products that are of high quality. Specifically, there are a few key factors we recommend you look out for.

Firstly, it’s best to opt for organic medicinal mushrooms. That way, you can rest assured that there were no pesticides or other unwanted chemicals used in their cultivation. Secondly, try to pick a product that’s 100% pure shiitake, and hasn’t been bulked out with filler ingredients.

Another important issue to bear in mind is the polysaccharide content of your shiitake. Experts believe these are responsible for many of the fungus’s health benefits, so you want to make sure you’re not missing out.

Here at Erbology, we’re passionate about medicinal mushrooms, and cultivate them under carefully controlled conditions. Our expert mycologists grow our shiitake in small batches on organic substrates, using the latest scientific research as their guide. This ensures our mushrooms offer you the maximum nutritional value, and you can enjoy the shiitake mushroom benefits mentioned above.

We also get an independent and accredited tester to quality-check the mushrooms and confirm they’re rich in beta-glucans. As a result, we can say with confidence that our shiitake contains over 30% polysaccharides, which is considered high.

Shiitake mushroom benefits: the verdict

Traditional medicine practitioners have been using shiitake for generations as a natural way to boost wellness. While there are still relatively few human studies into shiitake mushroom benefits, the results so far are looking very promising.

We’re excited to see evidence emerging that backs up ancient wisdom regarding shiitake’s positive effects on our wellbeing. From supporting the immune system to improving cardiovascular health, there are a whole wealth of potential shiitake mushroom benefits you might enjoy by including this fabulous fungus in your diet.

Related reading

• The Erbology guide to medicinal mushrooms
• Health benefits of lion’s mane mushroom