Mushrooms vs. cancer: Lowering risk and designing drugs
Experts still don’t understand all of the factors that increase or decrease our risk of cancer.
In 2020, more than 18 million people around the world received a cancer diagnosis. Though survival rates in the United Kingdom and the United States are slowly rising, treatments are still far from perfect.
So, researchers continue to search for ways to reduce the risk while designing better treatments.
While researchers know that dietary patterns play a part in cancer risk, the details in some areas are still murky.
And studying the effects of whole dietary patterns is challenging. So, some scientists are zeroing in on specific foods — like mushrooms.
Some research suggests that mushrooms might both reduce the risk of cancer and provide new ways to treat it.
Below, we’ll take a look at this research. First, let’s ask whether eating mushrooms might reduce your risk of cancer.
What’s so magic about mushrooms?
Mushrooms often get lumped into the “plants” category. But they’re not plants, they’re fungi. And fungi are as different from plants as plants are from animals.
There are an incredible 2,000 varieties of edible mushrooms. Because they’re so different from animal and plant foods, some authors call mushrooms the "third food kingdom."
Mushrooms contain a wide range of vitamins and minerals. For instance, some can be a source of vitamin D.
They also contain a heady mix of phytochemicals that might benefit your health, like flavonoids, as well as a range of antioxidants.
Eating mushrooms and cancer risk
Over the years, scientists have investigated whether people who consume mushrooms have a reduced risk of developing cancer. The results haven't been clear-cut.
While some researchers have found that mushrooms might be protective, others haven’t identified an effect.
For instance, a 2010 study in Korea concluded that consuming more mushrooms was associated with a reduced risk of developing breast cancer in premenopausal women.
But a 2019 study in the U.S. found no links between eating mushrooms and a range of cancers.
A review published in 2021 set out to draw a clearer picture, so the authors reanalyzed data from 17 studies. They concluded that “Higher mushroom consumption was associated with lower risk of cancer.”
When they looked at links between eating mushrooms and specific types of cancer, they only found a significant effect on breast cancer.
But, as the authors explain, this might be because most of the studies they analyzed had focused on breast cancer.
How would mushrooms offer protection?
According to the review's authors, mushrooms’ protective powers against breast cancer might come from their antioxidants.
In particular, the team points to an amino acid called ergothioneine, which is present in high levels in mushrooms. Your body can’t make ergothioneine, so it needs to come from your diet.
This amino acid appears to protect cells from free radicals. And, although its precise role in your body is still mysterious, some scientists believe it should be considered a vitamin.
Some have even given ergothioneine the heady title of “the longevity vitamin.”
But this is just one explanation of mushrooms' effects. It will be some time before scientists clarify the whole picture.
With so many types of edible mushrooms — all with different levels of a wide variety of compounds — it’s a challenging puzzle to piece together.
Interestingly, the authors of the review found that the anticancer effect was more pronounced in studies conducted in Asian countries than Western countries.
By way of explanation, they point to differences in the types and amounts of mushrooms eaten in the two regions.
All in all, scientists need to do more work to fully understand the link between eating mushrooms and cancer, if a link exists.
Mushrooms as cancer drugs
Over the years, scientists have tested extracts from many types of mushrooms against cancer.
Although some results are encouraging, much of the work has been in animal or lab studies. So, it will be many years before mushrooms reach the cancer clinic.
As someone somewhere once said, "Scientists have cured cancer in mice thousands of times."
Still, one can’t help but feel hopeful. Perhaps these humble fungi will eventually help eradicate cancer. But let’s not get ahead of ourselves.
Mushroom vs. cancer in research
The authors of a review looking at mushrooms as cancer treatments found that extracts from 92 species of mushrooms “showed promising anticancer effects” against 38 forms of cancer.
They also note that breast cancer seemed the most responsive — 61 extracts reduced the cancer cells’ growth and division.
Let’s take a brief look at three of these studies.
The mushroom of the sun
One group of scientists tested the mushroom Agaricus brasiliensis.
Also known as the mushroom of the sun and God’s mushroom, A. brasiliensis is native to São Paulo state, in Brazil.
The researchers fed four types of A. brasiliensis extracts to rats with tumors. They found that all four extracts slowed tumor growth.
A ‘new’ fungus
Scientists first described Antrodia cinnamomea in 1995. Native to Taiwan, it’s prized as a medicinal mushroom in traditional Chinese medicine.
Researchers tested extracts of A. cinnamomea on breast cancer cells in lab cultures and mice. They found that the extract reduced the size of tumors and slowed their growth.
Lion’s mane
The lion’s mane mushroom, or Hericium erinaceus, is edible, and a group of researchers fed extracts to mice with colon and lung tumors.
They found that the H. erinaceus extract reduced the size of tumors and prevented them from spreading.
We could go on. There’s a huge number of these early studies on mushroom compounds.
But, as Cancer Research UK explains, there's currently "no evidence that mushrooms or mushroom extract can prevent or cure cancer” in human beings.
Still, they point to "early research showing [that mushrooms] may strengthen the immune system.”
And a stronger immune system could help your body fight cancer more effectively. So, scientists continue to investigate.
Combining mushrooms with drugs
Rather than testing mushrooms alone, some scientists are investigating whether eating mushrooms might improve outcomes for people receiving standard cancer treatment.
Reishi mushrooms
A review of five studies looked at whether eating Ganoderma lucidum, also known as reishi mushrooms, alongside standard cancer treatment improved outcomes.
The authors concluded that “Patients who had been given G. lucidum alongside [...] chemo/radiotherapy were more likely to respond positively, compared to chemo/radiotherapy alone.”
They also noted that eating mushrooms was linked to increased immune activity.
Still, the authors acknowledge that the evidence so far isn’t particularly strong.
Shiitake mushrooms
Shiitake mushrooms contain a carbohydrate called lentinan. In some Asian countries, people have used lentinan as a medicine for thousands of years.
A review of 38 studies investigated whether this carb could improve health outcomes for people receiving standard lung cancer treatment.
The authors found that “Lentinan is effective not only in improving quality of life, but also in promoting the efficacy of chemotherapy during lung cancer treatment.”
A general review
A group of scientists reviewed previous investigations into the use of mushrooms to improve outcomes alongside standard cancer treatment.
Overall, they found that much of the research so far is “low quality.” But they also note that mushrooms might help boost patients’ immune responses against cancer.
According to the review's authors, most of the studies had concluded that “Mushroom treatments in combination with conventional therapies improves patients’ quality of life through improved physical, emotional, and cognitive function, and quality of sleep.”
They suggest that mushrooms might help patients deal with the side effects of cancer therapy and help bolster the immune system’s fight against cancer.
What should you do?
At the moment, the evidence that mushrooms can reduce cancer risk is limited. Still, scientists may discover a way to utilize these impressive organisms in medicine.
With more than 2,000 edible species, each possessing a unique collection of chemicals, researchers will hopefully find a way to use mushrooms as treatments for cancer one day.
For now, mushrooms are a nutritious addition to your diet. They’re rich in fiber, protein, vitamins, minerals, and other healthy plant compounds. So, as long as you don’t have a mushroom allergy, dig in.
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