Doctor's Note

Mushrooms appear to work in the lab to suppress breast cancer cell growth—but what about in the real world? That’s the subject of Why Do Asian Women Have Less Breast Cancer? The placenta study was profiled in Vegetables Versus Breast Cancer, and a comparison of the effects of different types of mushrooms can be found in Breast Cancer Prevention: Which Mushroom is Best? More on the magic of mushrooms in Making Our Arteries Less Sticky, and Constructing a Cognitive Portfolio. Probably a good idea to cook them, though; see Toxins in Raw Mushrooms? Also, I have dozens of other videos on breast cancer.

For more context, check out my associated blog posts: Ergothioneine: A New Vitamin?Why Less Breast Cancer in Asia?Vitamin D from Mushrooms, Sun, or Supplements?; and Mushrooms and Immunity.

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  • Jan

    Hello! Would cooked canned mushrooms work as well?

    • DD

      Would that be cans coated with hormone-disrupting plastic inside or cans with a metallic coating leaching into the contents ?

      Would that be mushrooms cooked in fluoridated or chlorinated water?

      • beccadoggie10

        You have a point there. Most cans do have epoxy of bisphenol A (BpA) in the cans.

        • beccadoggie10

          If you purchase a Multi-Pure 750 plus RO water filter, it can reduce the fluoride and chlorine, as well as some other toxic metals, volatile organic compounds, some pesticides in your tap water. That way, you can drink and cook with far cleaner water than bottled water and at a lower price.

          I gave my daughter’s family a Multi-Pure 750 Plus RO for Christmas last year because with a family it’s more important than ever that they reduce the fluoride and pesticides in their tap water.

          The unfortunate thing is the filter only reduces what is ingested. Fluoride can enter the body through the skin as well as by drinking and eating food. And, because Austin, TX is still in a drought, the wasted water would be prohibitively expensive.
          VOC’s and pesticides can also go through the skin, but a carbon filter does not waste water, so if that is your main problem, a whole house carbon filter is do-able.

          Have your water tested to learn what and how much is in your water. If your municipality is adding fluoride, by all means get a Multi-Pure 750 plus RO.

          If you live in California, all the pesticides that can be reduced in your water there.
          For the full performance data sheet of what can be reduced in your water, see:

          Keep in mind, no water filter will reduce everything that could be in your water, nor are there standards for the 80,000 chemicals the industry produces every year. But, by having an idea what’s in the water, and looking for a filter that is certified by NSF in that what the company claims if actual, you will be ahead in the long haul.

    • Thea

      Jan: I don’t know about the canned part (see DD’s response), but you definitely do want to cook your mushrooms. Dr. Greger has a video (linked to above) about toxins in raw mushrooms. Those toxins are destroyed with cooking.

      I have a tip for you that has worked really well for me. The beauty of canned food is the convenience, so I assume that you are interested in avoiding the cleaning and slicing of mushrooms as well as the time involved in sauteing.

      Here’s what I do: I buy pre-cleaned, pre-sliced mushrooms from Trader Joes. (You can probably get them elsewhere too.) The packages come in white button and criminy (sp?) varieties. Cooking could not be easier:
      …[1] Open package and dump in microwave-safe bowl.
      …[2] Cook on high for 4 minutes. (time will vary with microwave and amount cooked)

      It really is that simple, and they come out absolutely delicious. No oil is needed. The intense mushroom liquid at the bottom of the bowl can be used for cooking other things (broth for quinoa?) or simply drink it as a special nutrient-rich, flavor-filled treat.

      I cook a package or two of mushrooms on the weekends and then throw them into various dishes. Though I still need to try to get more into me if I’m going to hit an average of 5 mushrooms a day. Since I like mushrooms, that’s not a big hardship. (leafy greens on the other hand… {sigh!})

      Hope you found that helpful.

      • beccadoggie10

        I’ve read that microwaves destroy the nutrient value of food.

        • Thea

          beccadoggie10: The idea that microwaves destroy nutrient value of food any more than any other kind of cooking is an “old-wives tale”. If you search on this site, you will see that Dr. Greger has at least one science-based video showing that some veggies keep their nutritional value best when cooked via microwave compared to other cooking methods.

          My take: I love the microwave. It makes cooking dramatically easier for many dishes. I’ve never seen any credible evidence that microwave cooking is any worse in general than any other kind of cooking – and sometimes the opposite seems to be true (that microwave cooking is better). So, I encourage people to use the microwave as a great tool in the cook’s toolbox.

          For anyone interested: I recently got a book on vegan microwave cooking. While only a few of the recipes appealed to me (though those few were great!), I learned some great techniques and gained a lot of confidence on taking many recipes from other books and cooking all or part of them in the microwave. Works GREAT! Saves time and dirty dishes and helps keep me eating healthy.

          That said, a lot of people are afraid of microwave cooking. Certainly, no one *has* to use the microwave to be healthy. If you prefer not to, I respect that. Good luck.

          • beccadog

            40% of what is printed in newspapers, and aired in turn on the radio and television is from public relations firms who protect vested interests while keeping the public controlled and ignorant. This topic was explored in the book, “Trust Us, We’re Experts: How Industry Manipulates Science and Gambles with Your Future,” authored by Sheldon Rampton and John Stauber. The book explores the chilling, documented history of ongoing corporate efforts to use propaganda and “public relations” to distort science, manipulate public opinion, discredit democracy, and consolidate political power in the hands of a wealthy few.

            If microwaves are so safe, why did the Russians ban this appliance? Dr. Mercola explores the microwave at:

            “Research shows that your microwave oven will NOT help you…to maximize the “bang for your buck” when it comes to the foods you eat—and in fact will threaten your health by violently ripping the molecules in your food apart, rendering some nutrients inert, at best, and carcinogenic at its worst….

            “Microwaves heat food by causing water molecules in it to resonate at very high frequencies and eventually turn to steam which heats your food…causes a change in your foods chemical structure…(Another reason is) with microwave ovens is that carcinogenic toxins can leach out of your plastic and paper containers/covers, and into your food.

            The January/February 1990 issue of Nutrition Action Newsletter reported the leakage of numerous toxic chemicals from the packaging of common microwavable foods, including pizzas, chips and popcorn. (I realize you won’t be eating these foods, but look at the data.)

            Chemicals included polyethylene terpthalate (PET), benzene, toluene, and xylene. Microwaving fatty foods in plastic containers leads to the release of dioxins (known carcinogens) and other toxins into your food.

            [Sources: Watanabe F, Takenaka S, Abe K, Tamura Y, and Nakano Y. J. Agric. Food Chem. Feb 26 1998;46(4):1433-1436 AND Rust S and Kissinger M. (November 15, 2008) “BPA leaches from ‘safe’ products” Journal Sentinel Online ]

            ‘One of the worst contaminants is BPA, or bisphenol A, an
            estrogen-like compound used widely in plastic products. In fact, dishes made specifically for the microwave often contain BPA, but many other plastic products contain it as well.

            Microwaving distorts and deforms the molecules of whatever food or other substance you subject to it. An example of this is blood products.

            Blood is normally warmed before being transfused into a person. Now we know that microwaving blood products damages the blood components. In fact, one woman died after receiving a transfusion of microwaved blood in 1991 , which resulted in a well-publicized lawsuit.’


          • Thea

            As this is not a page for a discussion on microwaves, we will just have to agree to disagree on this topic for the most part.

            Happily there is one area on this topic that we sort-of agree: heating in plastic of any kind is not a good idea. (This is why I only cook with glass and ceramics in the microwave. And getting back on topic – mushrooms cook **great** in a glass container in the microwave.)

            The “sort-of” part? Well, cooking in plastic is not a good idea for any medium of cooking, not just the microwave. Bringing plastics into a microwave discussion is somewhat off topic…

            Anyway, as I said, if you don’t want to use the microwave, I respect that. Sticking to a whole-plant food based diet is a great way to live whether you use the microwave or not. Best of health to you.

          • melanie

            All cooking changes the chemical composition of the food. That is the point of cooking it! The question is whether the changed composition will do harm. We are the guinea pigs for future generations. We may not know for 60 years, and even then, there are so many new synthetic additives and environmental pollutants, it may be difficult for the research to come to any conclusions even over the long-term. I personally prefer to reheat food, as opposed to long-term cooking in the microwave, but I’m on the fence about it. Going into my second year of veganism, my goal is to simplify my food preparation by focusing on minimal prepwork meals, like sandwiches, cereal for breakfast, and casseroles that only take 10 minutes or less of prep.

          • Thea

            melanie: Yes, all cooking changes the chemical composition of food. (The raw foodists would suggest that we shouldn’t cook anything by any means.) That is not in dispute. What beccadog and I were discussing was whether or not microwaving is worse/different than other forms of cooking.

            The science on this topic is well understood. Happily, there is no experiment going on here. If you are interested in learning from a fairly easy explanation of the science and a good debunking of the microwave myths/scare stories, check out this site (or find others):


            I don’t know much about the person running the site, but I think the content of this particular page is fairly digestible for the lay-person, fairly complete in coverage, and properly has references. I got a huge kick out of her closing remarks. You might want to check those out first if you are on the fence about the microwave as a cooking device. It is an impressive statement in my opinion.

            That said, I’ll repeat to you what I said to beccadog: Despite the sometimes superior results of microwave cooking for health outcomes, no one *has* to use the microwave to be healthy. If cooking with a microwave scares you, by all means, don’t use it. While I think the microwave can make it so much easier for people to eat healthy and has an important place in the modern cook’s toolbox, by far the most important thing to do is to eat a whole-plant food based diet as described on this site and elsewhere – however you get there. More power to you, Melanie! I applaud your efforts these last couple of years. You are head and shoulders above the majority of people in the US. (where ever you live) You should be proud.

          • esther4


      • beccadog

        Leafy greens like collards, bok choy, kale, broccoli are not bad tasting once you learn how to prepare them. I found two ways. One is to mix certified organic Eden Organic Miso (one teaspoon to one tablespoon depending on how salty you want your food) in about a cup of water, stirring well to dissolve. Then adding the chopped veggie. Collards take the longer to cook. But, just before cooking is finished, drain but do not discard the miso broth, and hold. Sautee the diced and smashed fresh garlic and fresh ginger in organic olive oil (up to a tablespoon). Don’t let either burn.

        Then add the partially cooked veggies and keep stirring to coat all surfaces adding extra flavor and anti-inflammatory benefits of the fresh roots. Remove veggies and enjoy.

        You can add the saved broth to the garlic and ginger infused oil and serve as a tasty tea or broth full of beneficial vitamins including Vitamin K1 and K2.

        • Thea

          beccadog: Thanks for taking the time to share your methods with leafy greens. I’ve worked hard on my leafy greens, trying many times with many cooking methods. I’m always happy to try out another idea. You never know what will work.

          Of course, I’ll have to modify your method for the microwave. ;-) Hee, hee.

        • melanie

          I don’t know why people say collards have to be cooked longer. I eat them raw, as a burrito wrap when I don’t have tortillias. Or, I cook up those soup mixes you get at the store (just different beans, or beans and whole wheat pasta from Bob’s Red Mill), and throw in whatever veggies I like in my slow cooker. 3.5 hours later, I’m eating.

          With mushrooms, I love them steamed. They taste like deep fried mushrooms (think Japanese tempura) but without the grease! I also put extras (sliced or chopped, uncooked) in the freezer and pull them out to add to pasta sauces and soups.

          • beccadoggie10

            I learn something new every place I go. I eat mushrooms sauteed in olive oil, steamed (which is even healthier, and then miso added afterwards for seasoning, added to other veggies. It doesn’t matter. What’s important is that they are cooked.

            On several occasions when I felt I was coming down with the flu or whatever virus was in the air, I bought an assortment of mushrooms and made it into a soup with sauteed red onions, garlic, and kale or collards, carrots, even ginger and tumeric, then miso added lastly for flavoring. Whether it was the mushrooms, or everything in the soup, I know not, but it built a wall around my body and protected me against the invading virus.

   going to be a tough flu season with the flu so widespread. Most people I know are sick. I’m doubling up with mushroom, vitamins A and C in produce, red Bermuda onions and lots of garlic, ginger and tumeric to keep me well…and plenty of miso. Hope it works!

        • Huvs

          So what is the second way?

  • Syndee

    Why white? Would Shitake, Mitake, or even brown crimini have the same compound? Cooked or raw? And why breast cancer? Could it be that the same compound reduces other types of cancer? Is it merely because the studies have only been directed towards breast cancer?

    • If you look in the Doctor’s Note section beneath each video I try to put each video in context. So as you can see in this one I point to a previous video on did comparing different types of mushrooms: Breast Cancer Prevention: Which Mushroom is Best? Hope that helps!

    • DD

      I would think white mushrooms were chosen to make the point that the most common,readily available mushroom will do the trick,never mind having to go out of your way like hopping over to France/Italy etc with your pig to find truffles.
      I live with a fool who consumes that horrible poison Aspartame daily ,but I have her on `shrooms until she sees the light.
      Personally, my vegan,organic mushroom consumption of various types, keeps my Vitamin D3 levels high enough(above 80nmol/L all year round), to help protect me from at least sixteen types of cancer.I suspect that the reason the doc has chosen to concentrate on breast cancer is because those were the cells chosen for testing, as that type of cancer has reached epidemic proportions ,so the real humanitarians are showing the quacks the way to go,by offering a solution.

      • The mushrooms are effective in slowing breast cancer due to a compound present in the Agaricus spp, which inhibits the enzyme aromatase. Many breast cancer drugs, such as tamoxifen, work by either blocking the oestrogen receptors or preventing its production from other hormones. Other mushrooms would only work if they contained this aromatase inhibiting property, and yes, it would be specific to breast cancers or tumours that are oestrogen dependent.

    • beccadoggie10

      According to Dr. Andrew Weil, M.D. Mushrooms should NEVER be eaten raw; they should be cooked.

      “Dr Weil told Dr Oz that that cooked Asian mushrooms like Shiitake
      Mushrooms, Maitake Mushrooms, Oyster Mushrooms and Enoki Mushrooms all help to increase your immune function and protect you from Cancer and Viral Infections. Weil said not to eat mushrooms raw though, because your body cannot digest them raw or get any nutrients in that form.” Source:

      For an oil, Dr. Weil recommends Lucini Limited Reserve Extra Virgin Olive Oil from Lucini Italia Organics. He suggested purchasing the smallest bottle.

    • beccadog

      The study cited by Dr. Greger studied various mushrooms but the scientists discovered that white button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation. That was the conclusion of their study which was published in J Nutr. 2001 Dec;131(12):3288-93 and entitled White button mushroom phytochemicals inhibit aromatase activity and breast cancer cell proliferation. (See the last line of the abstract by
      Grube BJ, Eng ET, Kao YC, Kwon A, Chen S.

      There is another study, that found the same in true with prostate cancer in men with regards to the white mushroom. Nutr Cancer. 2008;60(6):744-56. doi: 10.1080/01635580802192866.
      White button mushroom (Agaricus bisporus) exhibits antiproliferative and proapoptotic properties and inhibits prostate tumor growth in athymic mice. Adams LS, Phung S, Wu X, Ki L, Chen S.
      The full study was at:

      Why breast cancer and prostate cancer? Of the two teams of scientists, one studied breast cancer, while the other studied prostate cancer. Why the white mushroom? That was the one that showed up best in their published results.

      This is what was written in part in one of the abstracts, entitled:

      White button mushroom (Agaricus bisporus) exhibits antiproliferative and proapoptotic properties and inhibits prostate tumor growth in athymic mice.

      “White button mushrooms are a widely consumed food containing phytochemicals beneficial to cancer prevention. The purpose of this research was to evaluate the effects of white button mushroom extract and its major component, conjugated linoleic acid (CLA) on prostate cancer cell lines in vitro and mushroom extract in vivo. In all cell lines tested, mushroom inhibited cell proliferation in a dose-dependent manner and induced apoptosis within 72 h of treatment. CLA inhibited proliferation in the prostate cancer cell lines in vitro.”

      In the other studies, which Dr. Greger cited, the white mushroom blocked the inflammation stage that followed the build up of cholesterol in the body. Hence, the white button mushroom is the most anti-inflammatory mushroom cited by the study at Arizona State University. He explains the results, which include: Plain white mushrooms worked the best! The cheapest, most convenient to
      find mushroom appeared to suppress inflammation the best. He also says to be certain to COOK the mushrooms. See:

      • melanie

        I prefer oyster and shiitake mushrooms because they aren’t grown on manure. My local mushroom company purchases horse manure from hundreds of miles away, and that is their major input cost, so I prefer to eat something grown on a non-animal based growing medium. Otherwise, I’d be going for white, cremini and portobellos (which are just mature cremini with exposed gills). In the meantime, I have some research to do on chanterelles. Morels are expensive, and I didn’t enjoy them as a teenager, but I might try them again. They are wild harvested a season after a forest fire, so I guess their medium is basically ash.

  • Thea

    This information about mushrooms is ***finally*** starting to make it into the bigger population. I remember learning about it from Dr. Greger a LONG time ago. :-)

  • Are the mushrooms to be RAW or COOKED? I assume it does no good if one’s diet is the S.A.D. Is Mushroom to be eaten or taken as a supplement? Please give us more information! Thank you.

  • thissal

    I love raw mushrooms and cooking spoils it for me so I looked up the following:

    The kicker with Agaricus species, including the buttons, is
    that one of their primary hydrazine components, along with
    gyromitrin, is “agaritine,” a substance somewhat resistant
    to cooking heat, with a significant percentage (25–75%) of
    agaratine material typically remaining after being subjected to
    various methods of cooking. So, the question as far as avoiding
    hydrazines in Agaricus is concerned, actually becomes whether
    to eat members of this genus at all.

    We need to keep in mind that lab tests and subsequent
    conclusions drawn concerning carcinogenic or mutagenic
    health hazards of hydrazine involve massive doses of isolated
    extracts administered to mice in a concentrated time frame.
    Similarly disturbing test results are likely to be found with many
    substances present in many, many foods humans commonly
    eat without suffering or even worrying about any particular
    health concern. The relatively unblemished human history of
    consuming edible Agaricus species suggests we may continue to
    do so.

  • Love mushrooms.

  • jaquelinetelf

    would magic mushrooms work? ;)

  • lovestobevegan

    Enjoy the cancer prevention properties of large button mushrooms in my take on stuffing.

    Not Your Mother’s Stuffing

    – 1 cup uncooked mung beans
    – 1 cup uncooked millet
    – 5 cups water/homemade vegetable broth
    – 2 cups large button mushrooms, sliced
    – 2 cups carrots, diced
    – 1 large onion, chopped
    – 3 cloves garlic, minced
    – 1 tbsp sage
    – 1 tbsp rosemary
    – 1 tsp thyme
    – black pepper

    Place all ingredients in a large pot and bring to a boil. Lower heat and simmer until mung beans are soft, about 45 minutes. Season to taste with sea salt.

    Bookmark my new Plant-Based Emporium Facebook page for all my latest recipes.

    ~Complements of lovestobevegan

  • melliforte

    I am all for eating fresh mushrooms, at least slightly cooked. Do any mushroom extract supplements such as beta – 1,3/1,6-d-glucans or AHCC (Active Hexose Correlated Compound) have credible evidence of efficacy in strengthening the immune system?

  • Linda

    Dr. Greger,
    My 95 year old mother currently takes a prescription aromatase inhibitor for her locally advanced breast cancer and it has been working great thus far (~6 months). However, I note that increased fracture risk is the leading side effect of this medication. Could the same negative side effect be expected with regular ingestion of mushrooms? That is, could mushrooms be bad for the bones?

    • Mimi

      Good question!

  • esther4

    Love it, Dr. G
    This was a 1, 2 punch!