A popular newsletter recently touted that red reishi extract does the following things. Not our claims, but theirs:

  • Adaptogenic properties [improves ability to handle stress]
  • Balances the immune system
  • Liver detoxifier
  • Respiratory health
  • Promotes neuroprotection

They claim it’s called “the mushroom of immortality” in China, where it has been used for over 2,000 years as an herbal remedy (which appears to be true) and that it’s “the most well-studied herbal medicine on the planet” (which is false).

Looking outside that newsletter, you hear about even more supposed reishi Mushroom health benefits. Aside from the more generic uses, such as its claimed ability to fight fatigue, aide meditation, and helping one get a better night’s sleep, some people are making pretty bold claims about it being beneficial for cancer and other major diseases.

emergency roomThose kinds of claims can be extremely dangerous, as treatments for serious diseases are not a time you want to be fooling around.

If you use it for sleep and it doesn’t work, the worst side effect you will probably have is that you’re tired the next day. Bad, but not the end of the world.

On the other hand, if you were to use it to treat a life threatening disease, the resulting side effect might actually be that you die. Your life is at stake, are you really going to trust that with unsubstantiated advice you read on an herbal remedy website?!

It is true there has been reishi mushroom research for cancer (including leukemia, which is cancer of the blood), liver enzymes, proteinuria and uric acid (both related to kidneys), urinary tract infections, and HIV (including related CD4 lymphocytes). However the claims that some herbal medicine enthusiasts are making based on these studies are absolutely absurd.

In regards to cancer, let’s take a look at what some naturopathic and Eastern medicine websites are saying (who we will refer to as “they”) and how that compares to what the science actually says.

What “they” say

Also known as the lingzhi mushroom, the reishi includes several species of the genus Ganoderma. However the most common species, Ganoderma lucidum, is the type that the vast majority of people use as an herbal supplement.

What is the difference between red reishi vs. reishi? Nothing, as they typically both reference the same thing; Ganoderma lucidum. Some people just use the red moniker in front of the name, since that’s its color.

There are other colors, including the black reishi (Ganoderma sinensis) and even white, yellow, purple, and blue. With the exception of the black, which some Chinese herbal medicine stores sell, almost all talk of this mushroom is in reference to the red variety. Since the black has lower polysaccharide content versus the red, research has also focused on the red reishi (Ganoderma lucidum).

apoptosis process

the stages of apoptosis

They say that reishi powder or extract “has the ability to stop cancer cells in their tracks” because of apoptosis (programmed cell death) which the mushroom “intermediates” so that the cancer cells die off.

That’s pretty bold claim, considering the fact that nothing known to mankind “stops” cancer cells altogether, as that sounds like a cure for cancer?!

We would encourage reading the Pulitzer Price winning book The Emperor of All Maladies: A Biography of Cancer, which has also been a bestseller in the leukemia and oncology categories. It does an excellent job at explaining the many types, how they work, and why there will probably never be a universal cure for cancer, though possibly different cures for different types/causes. To make a statement that one medicine (or one mushroom supplement) can “stop” the umbrella term of cancer cells is coming from someone who clearly doesn’t understand that.

Anther mechanism of action we saw claimed was the mushroom’s purported ability to destroy the cancer cells’ outer layer of fibrinogen.

What the science says

Let’s start with the most touted, which is programmed cell death for cancer cells.

Programmed cell death (apoptosis) is how our bodies rid themselves of dysfunctional cells. A problem with malignant cancer cells is that they are known for evading the process, and hence, staying alive.

It is true that there are actually quite a few studies which have suggested reishi mushroom extract benefits this problem possibly, in that it might help promote apoptosis with cancer cells.

lab experimentHowever to date none of those studies involve humans. All are in vitro “test tube” studies done outside of the human body using cell cultures. While not ignoring the intriguing results, the fact is that what works in a Petri dish is not necessarily what works in the human body.

If you isolated cancer cells (or any cell type) and put them in a dish, there are all sorts of substances you could pour on to destroy them. That doesn’t mean that if you consume a pill or drink with the same substance, its destructive effect will be the same after being metabolized.

A study may involve a concentrated direct application in a Petri dish, while reishi mushroom tea might provide you with parts per million of the substance in your blood stream. Huge difference.

Plus, tumors living in a Petri dish are kind of like tomatoes living off the vine in the grocery store. Both can be alive temporarily, but it’s not the same as when they are living in their native environment, receiving all the nutrients they need to sustain ongoing life.

That being said, the in vitro studies are still intriguing.

Studies using animal models/cultures:

  • Leukemia cell line L1210 (1)
  • Lung cancer using Lewis lung carcinoma (LLC), a popular mouse model that’s been around since 1951 (2)
  • Prostate cancer using human PC-3 cells implanted into immunodeficient mice (3) (4)
  • Sarcoma S-180, Meta-A, and reticulocyte sarcinoma L-II (1) (5) (6)

Studies using human cell cultures:

  • Bladder cancer with HUC-PC cells for urothelial carcinoma, also known as transitional cell carcinoma (TCC) (7) (8)
  • Breast cancer using MDA-MB-123, which is a highly invasive breast cancer, MCF-7 which is an estrogen-dependent type, T-47D, and MT-1 (9) (10) (11) (12) (13)
  • Cervical cancer (14) (15)
  • Colon cancer from SW480 and HT-29 cell lines (16) (17)
  • Leukemia cell lines HL-60, Blin-1, K562, Nalm-6, RPMI8226, and U937 (18) (19) (20) (21)
  • Liver cancer cells HepG2, HepG3, SMMC7721, Huh-7, and PLC/PRF/5 (22) (23) (24) (25)
  • Lung cancer with the PG line that is a highly-metastatic giant cell, NCI-H69, and VPA drug resistant strain (the latter two are both small cell) (26) (27) (28) (29) (30) (31)
  • Prostate cancer using PC-3 cells, which are a common cell line used in research that do not respond to glucocorticoids, androgens, or fibroblast growth factors (32) (33)

Natural Killer cells

As a type of lymphocyte or white blood cell, you may have heard of Natural Killer cells, which are part of the immune system and demonstrate a natural toxicity against tumors and viruses. They’re also called NK cells, K cells, or just killer cells.

Some hot biotechs like NantKwest (backed by Celgene) and Sorrento Therapeutics are trying to develop cancel therapies which make use of NK cells. Though to be clear, their therapies have absolutely nothing to do with red reishi mushroom extract.

However there has been some research which has looked at whether reishi can promote NK cell activity in the body.

A study from a decade ago involving advanced colorectal cancer patients found that it did not increase NK activity (34).

An even earlier study from 2003 involved 34 patients with advanced-stage cancer. They were treated with 1,800 mg, taken 3x daily by mouth before meals. That continued this for 12 weeks. It was said that the treated patients experienced 34.5 +/- 11.8% increase in average NK activity versus the 26.6 +/- 8.3% for baseline (35). Below are the charts from this study.

charts of reishi effects on NK cells

Destroying the fibrinogen layer?

Another one of the benefits claimed by the herbal crowd is that this mushroom can destroy the fibrinogen, which is found in the outer layer of many types of cancer (36).

There was an in vitro study in 2012 where researchers applied the mushroom extract to see if it affected the fibrinogen’s adhesion to melanoma cell cultures. It was found to reverse the blocking effect of the fibrin coat. That, in theory at least, would better allow NK cells to do their thing against the tumor (37). Another paper published the same year also suggested it helped (38).

While this research seems to be good news, it’s hard to see how a study or two involving cell cultures in Petri dishes can justify the anti-cancer claims some are making about fibrinogen destruction benefits.

Human clinical trials

Searching the 26+ million records on PubMed for the words “reishi mushroom cancer” and “ganoderma cancer” didn’t produce many clinical trials. Twelve to be exact.

And many of those were unrelated to cancer.

For example, is reishi mushroom safe to use in healthy people? That’s what a couple studies were focused on – looking for possible side effects. They only mentioned the mushroom in an unrelated context to cancer.

One study concluded it was unlikely to cause increased surgical bleeding (39). Another said there were no signs of liver, kidney, or DNA toxicity in healthy adults taking 1.44 grams per day (equivalent to 13.2 grams of fresh mushroom) (40). It appearing to be safe is a good thing, but none of these have to do with cancer.

A couple studies involved a Chinese medical herbal complex where the mushroom was only one of many different ingredients (41) (42). That’s not very useful.

Ultimately, we only found three human clinical trials and while they were related, they were not evaluating reishi as a treatment for cancer.

Pre-cancerous bowel lesion study

gastric adenomas

While not from the study, here is an example of what gastric adenomas can look like. Those in the colon may appear similar.

Published in 2010, this study looked at 96 patients who had adenomas of the bowel, which are precancerous lesions (benign tumors). They were treated with reishi supplements (ganoderma lucidum mycelia) for 12 months and their results were compared against a 102 patients who were not treated (43).

  • The number of adenomas in the non-treated group increased 0.66 +/- 0.10 (mean +/- SE), while they decreased in the treated group -0.42 +/- 0.10 (p < 0.01).
  • The adenomas increased 1.73 +/- 0.28 mm in size in the non-treated group, while decreasing -1.40 +/- 0.64 mm in the treated group.

The conclusion was that the reishi extracts suppressed the development of precancerous colorectal adenomas.

Colorectal cancer patient immune system response

Published in 2006, this was an open-labeled study that had 47 enrolled patients with advanced colorectal cancer. They were treated with 5.4 gram per day dosage of reishi for 12 weeks (44).

Among those people, 41 were said to be “assessable” (if the other 6 dropped out or died, it was not clear). Throughout the study, various immune parameters were measured and it was suggested that the extract “may have potential immuno-modulating effect in patients with advanced colorectal cancer.”

Fatigue related to breast cancer

While it wasn’t categorized as a clinical trial by PubMed, there was a 2011 study done in China which suggested that the reishi mushroom spore powder might help with fatigue and quality of life in breast cancer patients who are going through endocrine therapy (45).

Medium-term effect on liver

In 2017 there was a double-blind and placebo-controlled study published which looked at the hepatoprotective (liver protective) effects the triterpenoids and polysaccharides might have over 6 months of usage.

Biomarkers suggested a positive effect on liver condition, especially for mild fatty liver, however these 22 men and 20 women were all “healthy volunteers” without cancer. So this study proves nothing about cancer prevention or treatment. (46)

Verdict?

Yes, there are a couple dozen or so interesting studies which looked at the reishi being used in vitro (e.g. Petri dishes, test tubes, and mice). However, none of those are proof it will do the same in the human body. Furthermore, comparing and contrasting the studies can be difficult, given that different dosages and extract formulations were used.

As far as the only three clinical trials which used living humans, they were looking at immune system response, precancerous lesions and the side effect of fatigue. Neither of these were using it as a cancer treatment.

In short, there needs to be a lot more research to find out whether or not this will be beneficial for cancer in humans. Right now it’s just far too early to know. It should NOT be used for any disease.

As far as helping with side effects of fatigue from chemotherapy or radiation treatments, to the best of our knowledge it hasn’t been clinically studied for that purpose, either.

Using it for other benefits?

You can use it as a food, but what reishi mushroom tea tastes like hasn’t been described enthusiastically. Due to its bitter flavor, we hear some people take it as shots.

As far as cooking, in Western countries it’s unheard of, probably because they’re not exactly a mushroom you can pickup at your local grocery store. Online, you can buy dried reishi mushrooms but we haven’t tried them yet ourselves, so we can’t comment on their culinary uses.

Fungi Perfecti reishi mushroom patch growing kitThere are also indoor reishi growing kits which can be used to grow the edible red mushrooms year-round. The customer reviews for it appear to be mostly positive.

As mentioned at the start, there are many other purported health benefits which have been claimed such as anxiety, stress, fatigue, and athletic benefits while taking it as a supplement. While there are some human studies which have concluded these and others might exist, they are not enough to prove the suspected benefits. Much more research needs to be done.

The “herb of spiritual potency” is the translation for the Chinese name of it, lingzhi. The Japanese call it mannentake which translates as “10,000 year old mushroom.” While both names sound enchanting, please don’t let the rich history of this fungus lead you astray in falling for over-hyped claims.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.