Have you wondered why reishi mushrooms are becoming trendy lately?
Despite their recent rise in popularity, reishi mushrooms have actually been around for more than 2,000 years.
This special type of mushroom is gaining traction thanks to a combination of science-backed health claims and ancient folklore touting its benefits. We were curious to learn more, and we’re sharing everything we think you need to know about these powerful mushrooms, including whether you should add them to your daily routine.
To start, let’s explore what makes reishi mushrooms so unique.
What Is a Reishi Mushroom?
Many people are surprised to learn mushrooms aren’t technically a vegetable. They’re actually the fruiting body of a fungus. Different types of fungus sprout different types of mushrooms.
So reishi mushrooms are simply a different type of fungus compared to your average white button mushrooms at the grocery store. And, reishi mushrooms look nothing like mushrooms you’re used to eating.
In fact, you probably wouldn’t want to eat a reishi even if you like mushrooms. Not only are they bitter in taste but they’re also tougher in texture. That’s why reishi mushrooms are typically ground into a fine powder and taken as a supplement. You’ll also find reishi mushroom teas and tinctures to sip on.
Reishi mushrooms take several months to grow and they only do so in hot, humid conditions. Since they’re only native to places such as Korea, Japan, and other areas in Asia, they’re now commercially grown to increase their availability (1). Today you’ll see reishi cultivated in North America, Taiwan, Korea, Japan, and China (1).
It should be no surprise that the cultural background of using reishi mushrooms for their awesome health benefits started where they were first discovered.
A Brief Cultural History of Reishi Mushrooms
Reishi mushrooms have been a staple in Asian cultures for the last 2,000 years.
In the early days, only wealthy people and the nobility could afford to buy reishi mushrooms since they were — and still are — very rare to find in the wild (1). Reishi naturally grows on decaying logs and tree stumps in places like the coastal regions of China, Korea, and Japan.
And since they’re cultivated from several areas, there are different variations. In China, for example, you’ll see black G. lucidum (the scientific name for reishi) as opposed to the red G. lucidum found in Japan (1).
Reishi mushrooms were believed to promote longevity and health in China. People called them an herb of immortality and spirituality (1). That’s why you’ll see reishi mushrooms idolized in paintings, on furniture, in accessories, and even on carvings from the time (1).
Fast forward to today and we now have the science to back up those health claims.
Top 6 Science-Backed Health Benefits of Reishi Mushrooms
Did you know that several “modern” prescription medications were actually derived from mushrooms?! It’s true. And the potential health benefits of reishi are probably more far-reaching than you’d think. Here are the top 6 currently known by scientific research.
1. Promote Health Through Bioactive Molecules
There is no one isolated compound in reishi mushrooms believed to be responsible for its many benefits. Instead, reishi contain multiple compounds known as “bioactive molecules.” These include phenols, terpenoids, steroids, and nucleotides. If you’ve never heard of the term, bioactive molecules promote overall health by helping your body run more efficiently. They help to keep blood sugar levels regulated and seem to improve an overall sense of well-being.
2. Provide All 9 Essential Amino Acids
If you didn’t already know, amino acids are the building blocks of protein. And yes — mushrooms have protein!
Even cooler, the protein found in reishi mushrooms is packed with all nine essential amino acids. (21) This makes reishi one of only a few plant sources that contains all nine essential amino acids. Why is this important?
Essential amino acids are the ones your body can’t produce on its own but still needs in order to function correctly. This means you must obtain essential amino acids from your diet.
- Managing blood sugar levels
- Supporting muscle growth and recovery
- Promoting the optimal amount of growth hormone
- Absorbing calcium
- Increasing muscle proteins
- Recovering from physical trauma
- Hormone and antibody production
Reishi mushrooms are also lower in fat. The fat reishi does contain is rich in polyunsaturated fatty acids, a type that can help lower bad cholesterol and decrease your chances of developing heart disease (4)(1).
3. Help With Diabetes
In a 12-week randomized, double-blind, cross-over study, participants were given 1.44g of reishi daily or a placebo.
After the trial period, researchers saw plasma insulin levels were lower and HDL-cholesterol — the good kind — increased in the reishi mushroom group. Those in the placebo group did not show these positive results (8).
Smaller studies also reported that the polysaccharides in reishi mushrooms may be helpful at regulating blood glucose levels (8).
While more research is needed to confirm these two findings, it’s safe to say the mushrooms did at least exhibit a mild antidiabetic effect.
4. Combat Fatigue and Feeling Unwell
Scientists in one trial wanted to see how reishi mushrooms would affect Chinese patients experiencing neurasthenia, an emotional condition that leaves people feeling tired, irritable, and with a headache.
The 123 patients in the trial were given up to 1,800mg of reishi three times a day over the course of eight weeks. After this period, researchers discovered the patients felt significantly better and lowered their symptoms after taking the mushroom extract over the placebo (9).
These findings were similar to another study which looked at fatigue in 48 breast cancer survivors. Along with reports of feeling better and less fatigue, the participants also lowered their anxiety and depression symptoms and improved their quality of life after taking reishi mushroom in the form of spore powder (10).
And this makes sense since, as you’ll see next, reishi mushrooms have an incredible impact on the immune system.
5. Helps Boost the Immune System
Research also supports that reishi mushrooms have immunomodulating properties, which means they can boost your immune system in a way that improves your health. Wondering how that’s possible?
Some emerging research has shown that reishi mushrooms stimulate important immune system cells which can be helpful in treating conditions like HIV, AIDS, and cancer, as you’ll see shortly with the latter (17).
And, with regards to advanced-stage cancer patients studied, another body of research found that reishi mushrooms amplified the immune response (17).
All of this is possible thanks to beta glucans, a complex sugar found in the mushrooms, which has powerful health benefits of its own.
When it comes to immunity, beta glucans help to boost the immune system in people who have a weakened immune system and are left defenseless against foreign invaders and pathogens due to poor health (18).
In addition, they can also help you get through cold or flu season (18).
6. May Help Fight Cancer Cells
You don’t need to look far to find people using reishi to support their efforts at battling cancer. There is no conclusive research yet showing that reishi will necessarily help, but there are some very promising studies in specific cancer-related circumstances:
In one study, researchers discovered that G. lucidum (aka reishi mushrooms) is a powerful nutraceutical — or food with medicinal benefits — that can help prevent cancer from spreading (5).
Another body of research determined that reishi mushrooms had several positive effects on ovarian cancer cells, such as (6):
- Decreasing the number of damaged cells
- Preventing cell colony formation
- Preventing cell growth in chemosensitive or chemoresistant cells
- Improving the effects of a chemo drug known as cisplatin
- Enhancing cell receptivity to cisplatin
- Killing cancer cells
A different study used male Swiss albino mice and an Indian strain of reishi to see how the mushroom’s polysaccharides affected tumors and inflammation (7). The scientists learned the mushrooms not only stopped the growth of the tumors in the mice studied but also reduced their size.
What’s even more interesting about this data is that the reishi mushrooms were just as effective at reducing the spread of tumor cells as a popular anti-cancer drug called cyclophosphamide.
Another trial examined the effects of reishi mushroom extract on 134 advanced-stage cancer patients using one 1,800mg dose daily for 12 weeks. Scientists noticed 80% of patients had improved immunity and increased levels of natural killer (NK) cells. These cells, as their name suggests, go after harmful tumor cells and kill them (1).
Studies performed with lung cancer patients documented similar results. But patients also improved their quality of life by an average of 65% with the reishi addition (1).
Reishi Health Benefits that Aren’t Well-Studied Yet
Though not yet as well-established, emerging research on reishi mushrooms also supports additional health benefits. The U.S. National Library of Medicine says these reishi benefits have come to light in studies but more research is still needed to prove them further (12)(17):
1. Potential Brain Benefits
One study found that reishi mushrooms have neuroprotective benefits and anticonvulsant properties, which could potentially make them helpful for combating seizures (19).
Another one conducted on mice found that the reishi mushrooms helped with improving memory and spatial learning, two things that could be helpful for preventing Alzheimer’s disease, according to the study (20).
2. Anti Aging Benefits
A study on mice indicates that supplementing the diet with reishi can protect the DNA from oxidative damage caused by the scavenging of free radicals. This is considered to be a major contributing factor to aging. (22)
3. Help Lowering Blood Pressure
Another animal study showed that compounds in reishi mushrooms could be responsible for decreasing blood pressure levels. (23) For this reason, as also detailed below, you’ll want to be careful about not taking reishi if you’re already on blood pressure medications.
4. Help Fighting Allergies
There are also preliminary studies indicating that reishi mushrooms can be an ally against allergies. They seem to have antihistamine effects and can also improve oxygen supply, which helps with allergy-related asthma. (24)
With all these amazing benefits, it’s easy to see why people have been using reishi mushrooms for thousands of years.
Should you start adding reishi mushrooms to your life? Before doing so, you should know about their potential side effects.
Potential Side Effects and Drug Interactions with Reishi Mushrooms
Before you rush out to buy some, here’s everything you need to know about the side effects and potential interactions supplementing with reishi mushrooms may cause:
Side Effects Associated with Reishi Mushrooms
- Nausea or upset stomach
- Dryness of the mouth, throat, or nasal cavity
- Rash or itchiness
It’s also not suggested to use reishi mushrooms if you are pregnant or breastfeeding since they’re not well-studied in these areas yet.
People with bleeding disorders or low blood pressure should also avoid reishi mushrooms, according to the U.S. National Library of Medicine (12).
Drug Interactions with Reishi Mushrooms
But those aren’t the only things to avoid mixing.
Here’s a list of everything that could have a negative interaction with reishi mushrooms (12):
- Antidiabetic drugs
- Antihypertensive drugs (high blood pressure)
- Anticoagulants and antiplatelet medications (blood clotting drugs)
- Any herbs and supplements that lower blood pressure, such as Q-10, casein peptides, fish oil, stinging nettle, L-arginine, or theanine
- Any herbs and supplements that lower blood sugar, including fenugreek, psyllium, ginseng, chromium, bitter melon, alpha-lipoic acid, and guar gum
- Any herbs and supplements that lower your blood clotting ability, such as clove, turmeric, red clover, or danshen
You should also stop supplementing with reishi at least two weeks before any surgery since it has the potential to increase bleeding (12).
Another important point to consider is the source of your reishi mushrooms.
Quality Matters When It Comes To Reishi Mushrooms
As with any supplement, the Food and Drug Administration (FDA) doesn’t strictly monitor what’s really inside reishi mushroom supplements you’ll find online or at your local health food store.
When they compared 19 reishi supplements, for example, they found only five legitimately contained what was advertised on the label (16)!
That’s why you’ll need to perform your own due diligence to find a high-quality option that’s worth taking. Choose your source carefully and always buy organic so you know the reishi used is free of harmful chemicals and pesticides.
Final Thoughts on Reishi Mushrooms
Reishi mushrooms have a long cultural history across Asia but they’re becoming more popular in the United States due to the many incredible health benefits backed by scientific evidence.
Don’t be surprised if you start seeing reishi mushrooms popping up all over the place soon — from supplements for better health to foods, drinks, teas, and more. Reishi mushrooms aren’t going anywhere anytime soon and for good reason.
So knowing all this, do you think you’re going to give them a try?