Are Reishi Mushrooms Good For Diabetes?

Fact checked by Victor Cheung

Advantages and Disadvantages of Reishi Mushrooms:

  • Reishi mushrooms have various health benefits
  • Reishi mushrooms play a role in managing and treating diabetes
  • We can find these mushrooms in various edible forms
  • Contrasting data about the efficacy and safety of Reishi are present in the literature
  • You should never mix Reishi with other medications
  • Pregnant women and those breastfeeding shouldn’t consume Reishi
  •  Unwanted toxic side effects can result from taking powder Reishi
  • It’s optimal to consult your doctor before taking any new medication or supplements including Reishi mushroom
  • Future efforts should be towards investigating the competence of the Reishi mushroom as an antidiabetic agent

“Let food be thy medicine and medicine be thy food” —Hippocrates

While keeping in mind the words of the wise Hippocrates, many researchers spend their time in the lab working on extracting compounds from natural products that can cure diseases.

This is the cue for us to talk about the King of Herbal Medicine studied for its possible link in treating various ailments. Namely, the Lingzhi mushroom or Reishi mushroom.

What are Reishi mushrooms and where are they found?

Reishi mushrooms are a type of fungus that can be found in hot and humid weather. They are mainly spread out across forested areas. They were primarily grown in Asian countries like China and Japan.1

In this time and age it is not required to book a flight to Asia to get a taste of the magic mushrooms, they can be found almost everywhere now in various forms. Some people even go through the trouble of growing it themselves at home.

What are Reishi Mushrooms good for?

Reishi mushrooms have several health benefits in improving the following conditions:2

Lingzhi mushrooms are good for blood pressure
Reishi mushrooms can help in the treatment of high blood pressure among other diseases

Long and promising as this list may be, scientists still have a long way to go to prove the efficacy and safety of Reishi mushrooms in treating these medical conditions. Nevertheless, we can bask in the small wins of research discoveries for Reishi mushrooms shaped in regulating blood sugar levels. Putting them in control of their life once again and with it removing all diabetes distress.

What is the scientific evidence behind the Reishi mushrooms’ antidiabetic properties?

We have gathered most of the data from the scientific literature to figure out the verdict on the beneficial effect of Reishi on diabetes.

A pre-clinical study done on laboratory mice in 2015 reported that Reishi mushrooms reduce the amount of sugar in the blood by increasing insulin hormone levels which in turn decreases the sugar level.3

Another study also conducted on lab mice added that Reishi mushrooms possess the ability to reduce glucose output by the liver and increase fat and skeletal cells utilization, which means that not only does it reduce glucose levels in the blood, but it also works on using it as an energy source instead of storage in the liver as it normally does.4

Results of research done on human beings

Moving on to data resulting from clinical research on humans, one trial estimated the efficacy and safety of the Reishi mushroom by giving 71 adult type 2 diabetic patients 1800 mg of the mushroom extract as an alternative to their normal intake of insulin for the duration of >3 months. Though participants in this trial were subjected to dose optimization and frequent blood glucose testing, it was evident from the numbers that Reishi mushroom showed favorable results in reducing blood glucose levels.7

Another clinical trial conducted on 84 diabetic patients with associated heart and metabolic disease comorbidities didn’t support the previous findings. In this study, participants were given Reishi mushrooms for 16 weeks and even though there were no reports of adverse events there were also no reports advocating the beneficial function of Reishi mushrooms in regulating blood glucose levels.8

What are some alternative names for Reishi mushrooms?

Reishi otherwise known as Ganoderma lucidum has multiple other names including the following:9

  • Lingzhi mushroom
  • Basidiomycetes Mushroom
  • Champignon Basidiomycète
  • Champignon Reishi
  • Mushroom of Immortality
  • Ling Chih
  • Ling Zhi
  • Red Reishi
  • Reishi Antler Mushroom
  • Spirit Plant

Are Reishi mushrooms edible?

Yes, Reishi mushroom is edible and is provided naturally as well as commercially in a variety of forms that can be commercially found online or even in stores, and they are:10

They are synthesized from various parts of the mushroom itself, namely the spores, mycelia, and fruit body. Surprisingly though, they can be quite expensive.

What is Reishi coffee made of?

It is also called Ganoderma coffee is a type of coffee composed primarily from the extracts of a medicinal mushroom named Reishi or Ganoderma lucidum. This coffee may also combine other ingredients like instant coffee, sugar, creamer, and some herbs, but the key ingredient with all the magic of changing lives lies with Ganoderma lucidum.

As for tea, it’s the same ingredients except for substituting instant coffee with tea.

Why are Reishi mushrooms expensive?

Reishi can be somewhat expensive because it almost takes around 1000 kilograms to make 1 kilogram of spores —the richest part of the mushroom— which makes it rather pricy.11

Nevertheless, it can be worth every penny spent when scientists finally reach a favorable verdict on its efficacy and safety.

What is the dosage of Reishi mushrooms?

There has been no agreement on a specific number when it comes to the recommended dosage of Reishi mushroom for treating diabetes. The effective dose accounts for many things like:

  • Age
  • Sex
  • Underlying medical conditions
  • Other medications
  • Reishi form whether (supplement, powder, extract)
  • The ailment for which Reishi is prescribed

Additionally, there have been very few clinical trials done on humans to determine the exact mechanism and dosage for Reishi12

Thus, it’s advised to ask your doctor first and follow their advice.

Are Reishi mushrooms poisonous?

There have been some initial reports claiming that the Reishi mushroom has both toxic and teratogenic effects upon long-term consumption which means that it’s not fully-proof safe yet.13

An unfortunate incident occurred in Hong Kong where a case reported 2 patients switching from Reishi tea to powder extract for 1 to 2 months causing one of them to lose their life because of liver toxicity and possible drug interactions.14

This doesn’t wipe away all its previously mentioned medical benefits but further stresses the fact that there’s a demand for further research on its safety and correct consumption dosage and form.

What are the side effects of Reishi mushrooms?

On one hand, Reishi extract seems safe for consumption for up to a year. On the other hand, taking powdered Reishi for more than one month carries the associated risk of causing irreparable liver damage — sometimes leading to death.

Evidently, there are some manageable side effects to Reishi mushroom intake, those are:15

  • Dry mouth
  • Upset stomach
  • Rash
  • Dizziness
  • Diarrhea
  • Headache
  • Nosebleeds

However, please note that several factors may have contributed to the above findings.

Reishi mushroom selection – There are more than a thousand types of reishi mushrooms, and only a few are beneficial to our health. For instance, reishi mushrooms grown on lacquer trees, maple trees, and willow trees are known to be toxic. Also, reishi grown in toxic environments are known to be poisonous because it absorbs from its surrounding environment. Further, reishi mushrooms that are not properly stored can become toxic because of mold or other fungus growing on or inside of it.

Reishi mushroom processing – How reishi mushrooms are processed can also affect its toxicity. For instance, it is known that different levels of heat treatment for reishi produce different amounts of sugar and probiotic L. casei. If reishi is not processed or extracted properly (or whether any chemical compound was used), toxicity can be the result.   Thus, it is likely that the side effects of reishi from these scientific studies are a cause of improper reishi mushroom selection or processing.

To attain maximum safety while taking Reishi, you must adhere to the advice of your care physician as they will know your medical history and any medication, you’re taking that can affect your state when combined with Reishi.

Does Reishi mushrooms interact with other drugs?

Reishi mushrooms should not be mixed with several medications to steer clear of any unwanted side effects. WebMD lists several medications that you should avoid while consuming Reishi, including but not limited to:16

  • Aspirin
  • Warfarin
  • Heparin
  • Non-steroidal Anti-inflammatory (NSAIDs)

They also suggest staying away from taking any Reishi if you’re pregnant or breastfeeding.

Since it’s generally well known that people react differently to medication and foods, you should also be wise to always consult your doctor before making any changes.

Precautions to be taken before using Reishi mushrooms

Granted, there’s a growing body of evidence revealing therapeutic benefits of the Reishi mushroom, perhaps even providing hope to a natural remedy treating a life-long burdensome disease like diabetes.

But then it’s important to also note that whatever little information we have right now should be further confirmed through additional investigations, especially since most of the data provided came from animal studies.

So, tell us what you think, Diabetes and Reishi: A Useful Cooperation? Or are they rather a hazardous one?

References

1.        Wachtel-Galor S, Yuen J, Buswell JA, et al. Ganoderma lucidum (Lingzhi or Reishi) – Herbal Medicine – NCBI Bookshelf [Internet]. 2011 [cited 2022 Mar 30]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK92757/

2.        Batra P, Sharma AK, Khajuria R. Probing Lingzhi or Reishi Medicinal Mushroom Ganoderma lucidum (Higher Basidiomycetes): A Bitter Mushroom with Amazing Health Benefits. International Journal of Medicinal Mushrooms [Internet]. 2013 [cited 2022 Mar 30];15(2):127–43. Available from: https://www.dl.begellhouse.com/journals/708ae68d64b17c52,72e9ed69099c0eef,6dfb82bc1b4e287a.html

3.        Ma HT, Hsieh JF, Chen ST. Anti-diabetic effects of Ganoderma lucidum. Phytochemistry. 2015 Jun 1;114:109–13. Available from: https://pubmed.ncbi.nlm.nih.gov/25790910/

4.        Pan D, Zhang D, Wu J, Chen C, Xu Z, Yang H, et al. Antidiabetic, Antihyperlipidemic and Antioxidant Activities of a Novel Proteoglycan from Ganoderma Lucidum Fruiting Bodies on db/db Mice and the Possible Mechanism. PLoS ONE. 2013 Jul 11;8(7). Available from: https://pubmed.ncbi.nlm.nih.gov/23874589/

5.        Khursheed R, Singh SK, Wadhwa S, Gulati M, Awasthi A. Therapeutic potential of mushrooms in diabetes mellitus: Role of polysaccharides. International Journal of Biological Macromolecules. 2020 Dec 1;164:1194–205. Available from: https://pubmed.ncbi.nlm.nih.gov/32693144/

6.        Wińska K, MacZka W, Gabryelska K, Grabarczyk M. Mushrooms of the genus ganoderma used to treat diabetes and insulin resistance. Vol. 24, Molecules. MDPI AG; 2019. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6891282/

7.        Gao Y, Lan J, Dai X, Ye J, Zhou S. A Phase I/II Study of Ling Zhi Mushroom Ganoderma lucidum (W.Curt.:Fr.)Lloyd (Aphyllophoromycetideae) Extract in Patients with Type II Diabetes Mellitus – International Journal of Medicinal Mushrooms, Volume 6, 2004, Issue 1 – Begell House Digital Library [Internet]. 2004 [cited 2022 Mar 31]. Available from: https://dl.begellhouse.com/journals/708ae68d64b17c52,0738f8d34e863c74,1629a45749954343.html

8.        Klupp NL, Kiat H, Bensoussan A, Steiner GZ, Chang DH. A double-blind, randomised, placebo-controlled trial of Ganoderma lucidum for the treatment of cardiovascular risk factors of metabolic syndrome. Scientific Reports. 2016 Aug 11;6. Available from: https://pubmed.ncbi.nlm.nih.gov/27511742/

9.        MedlinePlus. Reishi Mushroom: MedlinePlus Supplements [Internet]. 2022 [cited 2022 Mar 30]. Available from: https://medlineplus.gov/druginfo/natural/905.html#Dosage

10.      Wachtel-Galor S, Yuen J, Buswell JA, Benzie IFF. Ganoderma lucidum (Lingzhi or Reishi). Herbal Medicine: Biomolecular and Clinical Aspects: Second Edition [Internet]. 2011 Mar 28 [cited 2022 Mar 31];175–99. Available from: https://www.ncbi.nlm.nih.gov/books/NBK92757/

11.      Health Benefits of Lingzhi – Eu Yan Sang International [Internet]. [cited 2022 Apr 1]. Available from: https://www.euyansang.com/en_US/maximising-the-effects-of-lingzhi/eysherbslingzhi2.html

12.      Mojani Qomi MS, Hatami M. Effects of Powder, Extracts, and Components of Ganoderma Lucidum in Treatment of Diabetes. Journal of Guilan University of Medical Sciences [Internet]. 2021 Jan 1;29(4):86–101. Available from: https://journal.gums.ac.ir/article-1-2187-en.html

13.      Dulay RMR, Kalaw SP, Reyes RG, Alfonso NF, Eguchi F. Teratogenic and toxic effects of Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum International Journal of Medicinal Mushrooms, Ganoderma lucidum (W.Curt.:Fr.) P. Karst. (higher Basidiomycetes), on zebrafish embryo as model. 2012;14(5):507–12. Available from: https://pubmed.ncbi.nlm.nih.gov/23510220/#:~:text=Tail%20malformation%20was%20the%20most,10%25%2C%20and%2020%25.

14.      Wachtel-Galor S, Tomlinson B, Benzie I. Fatal fulminant hepatitis associated with Ganoderma lucidum (Lingzhi) mushroom powder – PubMed [Internet]. 2004 [cited 2022 Mar 31]. Available from: https://pubmed.ncbi.nlm.nih.gov/17621752/

15.      Reishi – Special Subjects – MSD Manual Consumer Version [Internet]. [cited 2022 Mar 31]. Available from: https://www.msdmanuals.com/home/special-subjects/dietary-supplements-and-vitamins/reishi

16.      WebMD. Reishi Mushroom: Uses and Risks [Internet]. [cited 2022 Mar 31]. Available from: https://www.webmd.com/vitamins-and-supplements/reishi-mushroom-uses-and-risks