 Let's say you're trying to lose 20 pounds, or boost your immunity, or increase your ability to fight COVID, or even cancer. Well, the amazing thing is, with the right diet, you are well on your way to achieving these vital health goals. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. Today we discover the power of medicinal mushrooms. And no, I'm not talking about that kind of mushroom. Here's our first story. Can mushrooms be medicinal? Mushroom-based products make up a sizable chunk of the $50 billion supplement market. This profitable trade provides a powerful incentive for companies to test the credulity of their customers. And sadly, unsupported assertions have come to define the medical mushroom business. For example, companies that market herbal medicines exploit references to studies on mice to promote their mushroom capsules for treating all kinds of ailments. But if you haven't noticed, we're not mice. I mean, it wouldn't be surprising if mushrooms have some potent properties. After all, fungi are where we got a bunch of drugs, not the least of which penicillin, and also a cholesterol-lowering drug lovestatin and the powerful immunosuppressant drug cyclosporin. Still don't think a little mushroom could have pharmacological effects? Don't forget, they can produce some of our most powerful poisons. Some kind of look the part like the toxic Carolina false morel, all toadstool-y and such, but others have more of an angelic look. Indeed, literally called the destroying angel, that's its name, and as little as a teaspoon can cause a painful, lingering death. So anyway, we should have respect for the pharmacological potential of mushrooms, but what can they do that's good for us? Well, consuming shiitake mushrooms daily improves human immunity, giving people just one or two dried shiitake mushrooms a day, about the weight equivalent of 5 to 10 fresh ones for four weeks, resulted in an increase in proliferation of gamma-delta T lymphocytes and doubled the proliferation of natural killer cells. Gamma-delta cells act as a first line of immunological defense and even better, natural killer cells kill cancer, and the shiitake did all this while lowering markers of systemic inflammation. Oyster mushroom extracts don't seem to work as well, but what we care about is if mushrooms can actually affect cancer outcomes. Shiitakes haven't been tried yet, but reishi mushrooms have after being used as a cancer treatment throughout Asia for centuries. Reishi mushroom for cancer treatment. What does the science say? A meta-analysis of five randomized controlled trials showed that patients who had been given reishi mushroom supplements, along with chemo and radiation, were more likely to respond positively compared to just chemo and radiation alone. Now, although adding a reishi mushroom extract improved tumor response rates, the data failed to demonstrate a significant effect on tumor shrinkage when the mushrooms were used alone, so they aren't recommended as a single treatment, but rather an adjunct treatment for patients with advanced cancer. Now, response rate just means the tumor shrinks. What we care about is whether or not it actually improves survival or quality of life. We don't have convincing data suggesting reishi mushroom products improved survival, but those randomized to reishi were found to have relatively better quality of life, so that's a win as far as I'm concerned. What about other mushrooms? Although whole shiitake mushrooms haven't been tested yet, there's a compound that's extracted from shiitakes called lentinin, which is said to have completely inhibited the growth of a certain kind of sarcoma in mice, but in actuality it only worked in one single strain of mice and failed in nine others, so are we more like the 90% of mouse strains in which it didn't work? We need human trials, and we finally got them. There are data on nearly 10,000 cancer patients who have been treated with the shiitake mushroom extract injected right into their veins. What did the researchers find? Well, find out next. A regular intake of mushrooms is said to make us healthier, fitter, and happier, and help us live longer. But what is the evidence for all that? Mushrooms are widely cited for their medicinal qualities, yet very few rigorous human intervention studies have been done. There is a compound called lentin, extracted from shiitake mushrooms. To get about an ounce, you have to distill around 400 pounds of shiitakes. That's like 2,000 cups of mushrooms. But then you can inject the compound into cancer patients and see what happens. The pooled response from a dozen small clinical trials found that the objective response rate was significantly improved when lentinin was added to chemotherapy regimens for lung cancer. Objective response rate means like tumor shrinkage, but what we really care about is survival and quality of life. Does it actually make cancer patients live any longer or any better? Well, those in the lentinin group suffered less chemo-related toxicity to their gut and bone marrow, so that alone might be reason enough to use it. But what about improving survival? I was excited to see that lentin evidently could significantly improve survival rates for a type of leukemia, and adding lentin increased average survival and reduced catechia, which is like cancer-associated muscle wasting, and improved cage-side health. Wait, what? Damn it, this was improved survival for brown Norwegian rats. So, that so-called clinical benefit only applies if you're a veterinarian. A compilation of 17 actual human clinical studies did find improvements in one-year survival in advanced cancer patients, but no significant difference in the likelihood of living out to two years. Even the compilations of studies that purport that lentin offers a significant advantage in terms of survival are talking about statistical significance. Lentin improved survival by an average of 25 days. Now, 25 days is 25 days, but we should evaluate claims made by companies about the miraculous properties of medicinal mushrooms very critically. Lentinin has to be injected intravenously. What about mushroom extract supplements you can just take yourself? Shataki mushroom extract is available through the internet for the treatment of prostate cancer for approximately $300 a month. So, it's gotta be good, right? Men who regularly eat mushrooms do seem to be at lower risk for getting prostate cancer, and not apparently just because they eat less meat or more fruits and vegetables in general, so why not give a Shataki mushroom extract a try? Because it doesn't work ineffective in the treatment of clinical prostate cancer. The results demonstrate that complementary and alternative medicine claims can actually be put to the test. What a concept! Maybe it should be mandatory before patients spend large sums of money on unproven treatments, or in this case, a disproven treatment. What about God's mushroom, also known as the Mushroom of Life, or Rishi Mushrooms? Conclusions. No significant anti-cancer effects were found, not even a single partial response. Maybe we're overthinking it? Plain white button mushroom extracts can kill off prostate cancer cells, at least in a petri dish, but so could the fancy God's mushroom, but that didn't end up working in people. You don't know if plain white button mushrooms work or not until you put it to the test. What I like about this study is that the researchers didn't use a proprietary extract, they just used regular whole mushrooms, dried and powdered. The equivalent of a half cup to a cup and a half of fresh white button mushrooms a day, in other words, a totally doable amount. They gave them to men with biochemically recurrent prostate cancer. What that means is the men had already gotten a prostatectomy or radiation in an attempt to cut or burn out all the cancer, but now it's back and growing, as evidenced by a rise in PSA levels and an indicator of prostate cancer progression. Of the 26 patients who got the button mushroom powder, 4 appeared to respond, meaning they got a drop in PSA levels by more than 50% after starting the shrooms. Patient 2 was my favorite. He had an exponential increase in PSA levels for a year. Then he started some plain white mushrooms and boom! His PSA levels dropped down to zero and stays down. Similar type responses with Patient 1. Patient 4 had a partial response before his cancer took off again and Patient 3 appeared to have a delayed partial response. Now, in the majority of cases, the PSA levels continued to rise, not dipping at all. But even if there's only a 1 in 18 chance, you'll be like these two with a prolonged complete response that continues to date. We're not talking about weighing the risks of some toxic chemotherapy for the small chance of benefit, just eating some inexpensive, easy, tasty plain white mushrooms every day. Yes, the study didn't have a control group, so it may have just been coincidence, but post-prostatectomy patients with rising PSAs are almost always indicators of cancer progression. And hey, what's the downside? I mean, these two patients, their PSA levels became undetectable, suggesting that the cancer disappeared altogether. They'd already gone through surgery, gotten their primary tumor removed, along with their entire prostate, already went through radiation, tried to clean up any cancer that remained and yet the cancer appeared to be surging back until, that is, they started a little plain mushroom powder. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials. We may be able to share it on social media to help inspire others. To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts podcast landing page. There you'll find all the detailed information you need, plus links to all the sources we cite for each of these topics. For a vital timely text on the pathogens that cause pandemics, you can order the e-book, audio book, or hard copy of my latest book, How to Survive a Pandemic for Recipes. Check out my How Not to Diet Cookbook, which is my latest, latest book. It's beautifully designed with more than 100 recipes for delicious and nutritious meals. And all proceeds I receive from the sales of my book's go-to charity. NutritionFacts.org is a non-profit, science-based public service where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles. Everything on the website is free. There's no ads, no corporate sponsorship, but strictly non-commercial, not selling anything. I just put it up as a public service, as a labor of love, as a tribute to my grandmother, whose own life was saved with evidence-based nutrition.