Have you heard about medicinal or functional mushrooms lately? We’re guessing you have if you’re reading this. But why? We can’t say the reason for their popularity right now (as opposed to, say, 50 years ago), but we’re glad they are finally getting attention. Let’s discuss a few of the reishi mushroom benefits. As well as a word of warning for those considering adding these fungi to their diet.
Ancient Egyptians and Chinese cultures have used medicinal mushrooms for centuries to promote general health and longevity. However, using mushrooms for medicinal purposes is a relatively new concept to Western cultures. We think of mushrooms as those things we fry up in some butter and garlic. Which is great, of course. But that’s not how other cultures view them.
Even though using mushrooms for health may be relatively new for some, their popularity is growing worldwide. In fact, Inkstone suggests mushrooms are the hottest growing health and wellness trend for 2021. And mushroom supplements are one of the supplements everyone will be taking next year.
Reishi (Ganoderma lucidum or called lingzhi) and chaga mushrooms are some of the most popular medicinal mushrooms and adaptogenic products on the market. In fact, reishi mushrooms are often called the “mushrooms of immortality”. Does that mean you’ll live forever? No! But can they help you live a little healthier? We think there’s a good chance!
Reishi mushrooms are associated with many health benefits, but are these benefits backed by research? There is also some concern with toxicity with reishi mushrooms. Therefore, understanding the risks and benefits with taking reishi is warranted.
Let’s take a deep dive into the reishi mushroom benefits and potential risks to see what the science says.
Background on Reishi Mushrooms
Reishi mushrooms grow in densely wooded, mountainous areas. They are hard to find; they grow on the dried trunks of dead plum, guercus serrata or pasonia trees. Both above and below ground parts of reishi can be used for potential health benefits.
According to a 2008 review on reishi mushrooms, there are over 2,000 species of reishi mushrooms, but only six kinds have been studied for health benefits. Of these six kinds the black (Ganoderma sinensis) and red reishi are most commonly used in supplements worldwide and studied for health benefits. Wild purple reishi sought after for it’s health benefits as well. But it is extremely rare to find and study.
1. Sleep Aid
The Chinese and Japanese have traditionally used reishi as a sleep promoting aid to help insomnia. Along the same line, reishi Chinese medical doctors prescribe reishi for some psychological and neurological conditions. The thought is that reishi can help with calming for promoting sleep as well as calming for some neurological and psychological conditions.
Does reishi really help promote sleep and help bring a sense of calm? The animal study provided mixed results. And we need more more human studies. A 2012 rat study concluded three day supplementation of reishi extract significantly increased total sleep time in rats. A 2007 rat study had similar results. We need more research to determine if reishi has the same effect in humans.
2. Brain Health
Can reishi mushrooms help with brain health? Some animal studies have shown reishi may have an effect against dementia and cognitive decline. A 2017 mouse study concluded reishi could be a regenerative therapeutic agent for the treatment of cognitive decline. A 2019 rat study concluded reishi extracts could help with delaying Alzheimer’s progression.
Even though these animal studies look promising, we need more research in humans. The current research is not conclusive when it comes to reishi helping alleviate Alzheimer’s issues.
3. Immune Health
Organic germanium, polysaccharides and triterpenes are all thought to help immune systems. And all of them appear in reishi. The reason these components may offer immune support is in part due to their antioxidant levels. In culture in vitro and in animal studies in vivo have shown these components can
enhance the proliferation and maturation of T and B lymphocytes, and other cells involved with immune health.
Reishi has been studied against viral infections such as cold sores, herpes and HIV. Some studies have shown reishi helped reduce time to heal from cold sores or herpes or act in synergy with certain medications to improve healing.
Reishi extract has also been shown to significantly inhibit all four types of allergic reactions.
These studies with reishi and immune health are promising. But more research is needed to confirm these benefits and for dosing, length and type of reishi supplement for boosting immune health.
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4. Liver Health
Animal studies have shown various reishi extracts may help protect the liver against injury. And it is considered to be protective of liver cells. According to Susan G Komen Complementary and Integrative Therapies, reishi may help improve liver function in people with hepatitis B but suggests there is insufficient evidence (research) to make a determination about reishi and improving liver health.
Keep in mind taking — reishi mushroom products are not intended to prevent or treat liver injury from hepatitis, cirrhosis or other liver injuries. We need much more research on how it can impact liver health in humans.
5. Cancer Fighting
How supplements or food affect cancer risk is never an easy answer. Cancer risk and cancer cell growth is complex and multi-faceted. Some studies have shown reishi may have some cancer fighting properties. But we need more research to determine how it works and which cancers may be impacted. Some studies with reishi and cancer are small and need to be replicated to confirm results.
Its high amount of antioxidants are another reason why reishi may be considered cancer fighting. Research confirms a diet high in antioxidants may help lower certain cancer risk.
Susan G Komen Complementary and Integrative Therapies suggests reishi may offer the following benefits associated with cancer. But, as usual, we need more research.
- Reishi mushroom extract may reduce the number and size of noncancerous tumors in the large intestine.
- Reishi mushroom has not been shown to shrink lung tumors. However, there is some research to suggest it might improve immune function and quality of life in people with lung cancer.
A 2016 review on reishi mushrooms for cancer treatment did not find sufficient evidence to justify the use of reishi mushrooms as a first‐line treatment for cancer. The authors suggest reishi could be administered as an alternative adjunct to conventional treatment in consideration of its potential of enhancing tumour response and stimulating host immunity.
6. Diabetes Treatment
Components of reishi have been proved to have a hypoglycemic effect in animals. What does that mean? A small study with 71 human subjects with type 2 diabetes found reishi supplemented for 12 weeks significantly lowered blood sugar in participants compared to the placebo group.
This study was promising,. But we need more support from larger studies with and without combination with conventional medicines. There are studies with conflicting results with reishi and impact on blood sugar. Consult your doctor, especially if you take blood pressure medication.
A Word of Warning with Reishi Mushroom
If you use moderation, reishi supplements are thought to be safe. But as with any supplement that needs more research we always want to provide both the positives and the potential negatives. The Susan G Komen Complementary and Integrative Therapies suggests:
- Reishi mushroom extract is POSSIBLY SAFE when taken appropriately for up to one year.
- Powdered whole reishi mushroom is POSSIBLY SAFE when taken appropriately for up to 16 weeks.
- Side effects from reishi mushroom are rare but could include dizziness, dry mouth, itching, nausea, stomach upset, and rash.
WebMD suggests to factor the following considerations for reishi mushroom supplement dosage:
- Your age
- Why you’re taking it
- Form of the mushroom
- Your overall health
Other contraindications for taking reishi mushroom benefits:
- Pregnant or breastfeeding
- Low blood pressure or on medication or take supplements to lower blood pressure
- On diabetes medication
- Low platelets, have bleeding disorder or take anticoagulant or antiplatelet medication
- Taking reishi mushroom supplements within two weeks of surgery
You should always consult your healthcare team before taking supplements. If you have any of the above considerations, it is especially important to consult your healthcare team before taking reishi mushroom products.
Reishi Mushroom Benefits – In Conclusion
We all know mushrooms, in general, are a healthy addition to any diet. But North Americans are used to only a handful of types of mushrooms. Whether they are button or shiitake, we only think about mushrooms as a healthy addition to a salad or pizza. But there’s a whole world of adaptogens and medicinal mushrooms out there they we aren’t even aware of. But that is clearly changing.
These fungi are not miracle cures. They won’t change the way you feel overnight. And we need to have a lot more research to figure out exactly what they do and don’t do. But what we do know seems promising. They have tons of antioxidants. Which is great. They also contain minerals and vitamins. Another check in the good box.
Asian cultures have taken these mushrooms for centuries to treat various conditions. Reishi is growing in popularity around the world as a supplement that can promote many health benefits. But, we need more research for definitive scientific support for these reishi health claims.
There are some contraindications for taking reishi, so talk to your doctor before adding it to your diet.
Holly Klamer MS, RDN is a Registered Dietitian and freelance nutrition and writer. She attended Colorado State University where she received her MS and RD certifications. She specializes in sports nutrition, culinary nutrition, disease management/prevention, and disordered eating. She enjoys traveling, trying new foods, running, and spending time outside.