Shiitake mushroom: properties, benefits and active compounds

The shiitake mushroom (Lentinula edodes) is one of the most cultivated and consumed in the world. Over the last few decades, nutritional research has focused on discovering why this particular species is so closely related to human wellbeing.

Beyond being a delicious ingredient in the kitchen and the original source of the famous umami flavour, this mushroom holds a very special set of nutrients inside. Its study invites us to view this food not only as a source of calories or vitamins, but as a set of natural substances that help our body maintain its balance.

To fully understand what this mushroom provides and why so many people seek it out in the form of a food supplement, we must first look at how it is built on the inside and what differentiates it from the vegetables we eat on a daily basis.

 

 

Properties of shiitake (Lentinula edodes) and its nutritional matrix

When we analyse shiitake, we have to go one step beyond classic proteins or fats. What really makes this mushroom special is its microscopic "skeleton".

• A very particular natural armour

  Plants use a substance called cellulose to give firmness to their stems, which we digest with some ease. Mushrooms, on the other hand, build their cell walls with chitin, the same tough material that forms the shells of crustaceans. It is right inside this natural "safe" where their best nutrients are hidden.

This protective network stores a series of compounds unique in nature. Let's see which are the most valuable parts of shiitake and how they act.

Lentinan and beta-glucans: the key to its properties

The carbohydrates we eat are usually like pearl necklaces that are very easy to take apart. Our stomach is perfectly prepared to break down simple sugars (like those in fruit or potatoes) and turn them into quick energy. However, the carbohydrates in mushrooms are linked in a much more complex way.

These complex chains are called beta-glucans. Imagine that, instead of a simple linear necklace, they are like a tangled net in three dimensions. As our stomach does not have the right "scissors" to cut such complex knots, these nets do not unravel during initial digestion. They pass almost intact through the stomach and reach our gut directly.

Among all the beta-glucans that shiitake has, there is one that stands out above the rest: lentinan.

• What is lentinan?

  Lentinan is a fibre exclusive to this mushroom. Its importance lies in the fact that it does not provide us with energy like a normal carbohydrate, but rather it reaches the gut and acts as a sort of messenger or "trainer" for our body's cells, helping everything to function in a coordinated manner.

Comparative table: The best of shiitake at a glance

Main component	What it does in your body	Detail to keep in mind
Beta-glucans	Fibre that feeds the intestinal flora	They are very different from those of cereals like oats.
Lentinan	Supports defence functions	It is the most sought-after compound in extracts.
Ergosterol	Helps to create vitamins	It is the plant equivalent to good cholesterol.
Eritadenine	Supports general metabolism	It is mainly found in the "cap" of the mushroom.

Ergosterol and its conversion into vitamin D

Another detail to highlight about the composition of this mushroom is ergosterol. It is a natural substance present in the "skin" of the mushroom's cells.

The most interesting thing about ergosterol is how it reacts to light. Just as our own skin is capable of manufacturing vitamin D when exposed to the sun, the mushroom does exactly the same.

 

 

Benefits of shiitake for the human body

Once we consume these nutrients, they start doing their job from the inside. Shiitake is not a stimulant that alters the body, but a food that promotes the natural balance of our systems, especially from the digestive tract.

Lentinan and the maintenance of the immune system

The gut is the great control centre for our defences. In fact, most of our protective cells live there. When lentinan and other shiitake beta-glucans reach the gut, they meet our white blood cells, which are like the body's "sentinels".

These sentinels have receptors on their surface. Interestingly, the tangled shape of lentinan fits into these receptors perfectly, like a key entering its lock.

Upon binding, lentinan gives a warning to the defences, keeping them alert and prepared. It does not accelerate them excessively, it simply helps them to be in their optimal state of functioning. For this reason, various studies suggest that regularly consuming this mushroom contributes to the maintenance of the normal function of the immune system¹.

Prebiotic fibre and the intestinal ecosystem

Not all the fibre in the mushroom is dedicated to talking to the defences. A large part continues its journey to the end of the gut to fulfil another vital mission: feeding our intestinal flora.

Our gut is full of good bacteria that need to eat. These bacteria love the complex fibres of shiitake. When they feed on them (what we know as the prebiotic effect), they produce protective substances that soothe the gut and strengthen its walls.

Having a strong and healthy intestinal wall is the first step to feeling good, having good digestion and making the most of the nutrients from everything else we eat.

Organic shiitake extract: why the format is crucial

You might be wondering: isn't it enough to eat the mushroom grilled? Consuming it in the kitchen is fantastic and provides fibre and minerals. However, to get truly useful amounts of lentinan, there is a small obstacle.

As we said at the beginning, the nutrients are locked in a very hard chitin "safe". If we chew the fresh mushroom, much of the best of the shiitake passes through our body without us being able to absorb it, because we cannot completely break that armour.

That is why, when looking for a use more focused on wellbeing, extracts are used.

• How is a good shiitake extract obtained?

  To release the nutrients, the mushroom undergoes prolonged boiling in hot water. The heat manages to "melt" that hard armour and releases the beta-glucans into the water. Then, the liquid is evaporated and we are left with a concentrated powder. This way, we ensure that the body can absorb it effortlessly.

Avoiding contaminants through organic farming (bio)

When choosing a supplement, the origin of the mushroom is everything. In nature, mushrooms act like real sponges. Their ecological job is to clean the forests and recycle organic matter. The problem is that if the soil where they grow has pesticides or heavy metals, the mushroom will also absorb them.

If we make a concentrated extract from a mushroom grown in contaminated soil, we will also be concentrating those toxins.

For this reason, choosing an organic shiitake extract is essential. The "Bio" or organic seal guarantees that the mushroom has grown in a pure environment, usually on natural wood logs, without pesticides or chemical fertilisers. This way we ensure we only take the good parts of the food, just as nature designed them.

How to take shiitake: practical daily uses

Since its way of acting is based on progressive balance, shiitake supplements are designed for the medium and long term, not as a one-day express remedy.

It is usually included in the dietary routine at specific times of the year when we feel we need a boost in our lifestyle.

Shiitake side effects and contraindications

The consumption of this food has an excellent safety record after centuries of traditional use. However, when talking about concentrated formats, a couple of details should be kept in mind.

In sensitive people, consuming the raw or undercooked mushroom in the diet can cause an itchy skin reaction, known as "shiitake dermatitis". Although the extracts used in supplements are processed and reduce this risk to a minimum, people who already know they have an allergy to fungi or mushrooms should avoid taking it.

On the other hand, when starting to take the extract, it is possible to notice some gas or a slightly bloated tummy for the first few days. It is a normal response of our body when suddenly receiving such a rich type of fibre for the intestinal flora.

Who should not take shiitake supplements

This supplement is not recommended for people taking medications to suppress the immune system (such as those prescribed after a transplant or for certain severe autoimmune diseases), as the mushroom could potentially interfere with the purpose of the medication.

Neither is it advised for pregnant or breastfeeding women, simply as a precaution, since there are no specific studies in these groups. As a general rule, if you have a pre-existing medical condition or take medication daily, the ideal thing is to consult your doctor promptly before trying something new.

Organic shiitake: an ancient ally adapted to modern life

Including Lentinula edodes extract in our day-to-day life is a great way to take advantage of the wisdom of ancient traditions, but adapted to what we need today. It is not a miracle product, but a natural aid that works from the foundation of our wellbeing: taking care of the gut and gently supporting our defences. By always choosing a concentrated format from clean organic farming, we ensure we are giving our body exactly the tools it needs to stay strong against the current pace of life.

Bibliography

1. Consuming Lentinula edodes (Shiitake) Mushrooms Daily Improves Human Immunity: A Randomized Dietary Intervention in Healthy Young Adults. Dai, X., Stanilka, J. M., Rowe, C. A., Esteves, E. A., Nieves, C. Jr., Spaiser, S. J., Christman, M. C., Langkamp-Henken, B., & Percival, S. S. (2015). Journal of the American College of Nutrition, 34(6), 478–487.
2. A Review on General Nutritional Compounds and Pharmacological Properties of the Lentinula edodes Mushroom. Finimundy, T. C., Dillon, A. J. P., Henriques, J. A. P., & Ely, M. R. (2014). Food and Nutrition Sciences, 5, 1095-1105.
3. Beta-glucans in higher fungi and their health effects. Rop, O., Mlcek, J., & Jurikova, T. (2009). Nutrition Reviews, 67(11), 624–631.

This article is strictly for informational purposes and does not replace the advice of a healthcare professional.