When mushrooms sprout from the ground in autumn, many people head to the forest. But mushrooms have long been used for more than just food. So-called “vital mushrooms” are said to promote health or even alleviate certain diseases. But what can they really do? How do the mushrooms work? And is there any scientific evidence for their effectiveness?
As early as the Chinese Empire, during the Han Dynasty, a little over 200 years after Christ, the Ling Zhi mushroom – known here as Reishi – was used in traditional Chinese medicine. Now social media influencers are repeatedly advertising the supposed effects of such “vital mushrooms”. They report a stronger immune system, improved performance and digestion. The mushrooms are available as powder, capsules or even coffee.
Studies not on humans
The most well-known medicinal mushrooms include Reishi, Shiitake, Chaga, Maitake, Lion’s Mane, Cordyceps, Agaricus and Hericium. What gives them their effect are so-called bioactive components, including beta-glucans, triterpenes and phenols. These compounds are said to prevent or alleviate all diseases, for example asthma, allergies, high blood pressure, type 2 diabetes mellitus, stomach ulcers and rheumatism. Some are even said to have a healing effect on cancer.
Studies – especially from Asia – actually provide evidence of positive effects of medicinal mushrooms. The shiitake mushroom is said to reduce inflammation and, in conjunction with the maitake mushroom, strengthen the immune system. The duo is also said to be helpful in treating some forms of cancer, gestational diabetes and high cholesterol. However, most of these studies are carried out by researchers on animals or in the laboratory rather than on humans. It is questionable whether medicinal mushrooms have the same effect on people.
Not an approved medicine
“In general, we know that there is something in the biological activity of fungal preparations,” explains biologist Marc Stadler from the Helmholtz Center for Infection Research to the Barmer health insurance company. “However, it is extremely difficult to prove how exactly the mechanisms of action in medicinal mushrooms work. In addition, the standardization that we need in order to develop a reliably dosed drug is difficult.” The mushrooms have not yet been approved as medicine in Germany and are therefore mostly sold as dietary supplements. This means that their production is subject to hardly any controls and the ingredients are neither standardized nor tested for effectiveness, safety or side effects.
“Products from Asia in particular often do not contain the specified substances or dosages and are often contaminated with harmful substances such as aflatoxins and other toxic fungal substances,” explains the consumer advice center. The organization therefore advises against self-therapy with medicinal mushrooms – especially if users are taking medication or undergoing chemotherapy. Then the desired effects can even have the opposite effect.