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Treating Prostate Cancer with Green Tea

Green tea has been called nature’s defense against cancer. Population studies linking green tea consumption with lower cancer risk have led some to advocate for the incorporation of green tea into the diet “so as to fully benefit from its anticarcinogenic properties.” What, after all, is the downside?

But, population studies can’t prove cause and effect. Indeed, “it is not possible to determine from these population-based studies whether green tea actually prevents cancer in people”…until it is put to the test.

Prostate cancer is preceded by a precancerous condition known as intraepithelial neoplasia. You can see a graphic of the progression at 0:41 in my video Treating Prostate Cancer with Green Tea. Within one year, about 30 percent of such lesions turn into cancer. Because no treatment is given to patients until cancer is diagnosed, this presents a perfect opportunity to try green tea. In the study, 60 men with precancerous prostate intraepithelial neoplasia were randomized into either a green tea group or a placebo group. Since it’s hard to make a convincing placebo tea, the researchers used green tea pills that were roughly equivalent to about six cups of green tea a day and compared them to sugar pills. Six months into the study, they took biopsies from everyone. In the placebo group, 6 of the 30 men developed cancer by the halfway point and 3 of the remaining 24 developed it by the end of the year. So, 9 out of 30 in the placebo group, about 30 percent, developed cancer within the first year, which is what normally happens without any treatment. In the green tea group, however, none of the 30 men developed cancer within the first six months and only one developed it by the end of the year. Only 1 out of 30 is nearly ten times less than the placebo group. This marked the first demonstration that green tea compounds could be “very effective for treating premalignant lesions before [prostate cancer] develops.” Even a year later, after the subjects stopped the green tea, nearly 90 percent of the original green tea group remained cancer-free, while more than half of the placebo group developed cancer, as you can see at 2:09 in my video. This suggests that the benefits of the green tea may be “long-lasting,” with an overall nearly 80 percent reduction in prostate cancer.

What if you already have prostate cancer? A proprietary green tea extract supplement was given to 26 men with confirmed prostate cancer for an average of about a month before they had their prostates removed, and there was a significant reduction in a number of cancer biomarkers such as PSA levels, suggesting a shrinkage of the tumor. However, there was no control group, and the study was funded by the supplement company itself. When an independent group of researchers tried to replicate the results in a randomized, double-blind, placebo-controlled trial, they failed to find any statistically significant improvement. Perhaps green tea is only effective in the precancerous state and not powerful enough “to meaningfully impact overt prostate cancer”?

It certainly didn’t seem to help for advanced metastatic cancer in the two studies that tried it. What’s more, doubt has recently been cast on the precancerous results. When researchers tried to replicate it, the green tea extract group only seemed to cut prostate cancer development about in half, which very well may have happened just by chance, given the small number of people in the study. So where does that leave us?

Unfortunately, green tea extract pills are not without risk. There have been about a dozen case reports of liver damage associated with their use. Until there’s more solid evidence of benefit, I’d stick with just drinking the tea. Green or black? A recent study that randomized about a hundred men with prostate cancer to consume six cups a day of green tea or black tea found a significant drop in PSA levels and NF-kB in the green tea group, but not in either the black tea or control groups, as you can see at 4:12 in my video. NF-kB is thought to be a prognostic marker for prostate cancer progression, so the green tea did appear to work better than the black tea.


What happens if we pack our diet with all sorts of plant foods? See my Cancer Reversal Through Diet? video.

Before and after: Learn about Preventing Prostate Cancer with Green Tea and Changing a Man’s Diet After a Prostate Cancer Diagnosis.

Similar studies were done with pomegranates. I discuss the results in Pomegranate vs. Placebo for Prostate Cancer.

Interested in other ways to prevent or treat prostate cancer? See:

What about green tea and other types of cancer? Check out:

For more on some of green tea’s other benefits, see:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

Discuss

Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.


52 responses to “Treating Prostate Cancer with Green Tea

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  1. “What, after all, is the downside?”

    I am having a difficult time finding information on metals contamination in tea, especially brand specific info. Aluminum, lead, mercury, cadmium, arsenic, plus legal and illegal pesticide contamination is commonly found in teas regardless if they are organicly grown, or not. https://www.hindawi.com/journals/jt/2013/370460/

    One question that comes to mind is, does 3 to 5 minutes of cold-brewing worth the trouble in getting less metals, and enough antioxidants? * And secondly, over the span of years, is daily ingestion of a ‘ heavy-metal-soup’ still worth the benefits we get from drinking tea?
    * I have been reading warnings recently to not brew tea for longer than 3 or 4 minutes, but I made this mitake in cold brewing tea in the past. I put 2 or 3 tea bags in a jug of water in the fridge. Not a good idea apparently.

    1. Barb,

      Unfortunately, it appears that we have seriously polluted the air we breathe, the water we drink, and the land we grow our crops in, and thus the food we eat.

      While there may be small steps we can take to decrease our exposure to these pollutants, I think the bigger steps we need to take are political: increase regulation and enforcement, especially requiring companies to remediate and even prevent the damage they currently cause to air, water, and land. This would apply to governments as well. And, to individuals: what do we do to decrease our production of environmental pollutants? What can we do? And do we do it?

      1. Dr J, re: ” increase regulation and enforcement, especially requiring companies to remediate and even prevent the damage they currently cause to air, water, and land.”

        I assume that you’re talking about the USA here. Reducing pollution really sounds like a noble ideal, but I would be interested in hearing your plan for forcing other countries to reduce their pollution. I’ve been reading that other countries produce far more pollution than the USA. In fact, the USA has been the leader in reducing air pollution from automobiles starting back in the 1970’s. And unless all countries cooperate, the one’s that do reduce their pollution will be at an economic disadvantage.

        1. Darwin Galt,

          As I understand it, the US is the second biggest emitter of CO2 in the world, with China coming in first, at almost twice as much. But the population of China is more than 4x that of the US: 1.44 billion, compared to about .33 billion. So, per capital, the US is the biggest emitter of CO2.

          I don’t know about other GHG emissions, some of which exert a greater effect than CO2.

          And I don’t worry so much about other countries; we can do better right here. But the talk is of rolling back emission and pollution standards. That’s crazy. Let’s clean up our own backyard first, before waving the finger at other countries. Because that’s just an excuse for doing nothing here.

          1. Dr J,
            Unless all countries cooperate, the one’s that do reduce their pollution will be at an economic disadvantage. The US has been at an economic disadvantage in trade with other countries for many years now, up until very recently.

            I would love to see all the countries of the world work together to reduce pollution. But from what has happened in the past, the US is the only one who gets stuck with the disadvantage.

            Unless someone comes up with a plan for all countries to play on a level playing field, the US will continue to be taken advantage of. The US made the first concessions back in the 1970’s with reducing automobile pollution. 50 years later, I would think it’s time for other countries to clean up their act first this time.

            1. The US has a far more contaminated food supply than other industrialized countries. You can’t sell a lot of the GMO, polluted food in Europe, so they sell it here. We primarily have the businesses police themselves, so the studies, as Dr. Greger has shown, are dramatically different when they come from the businesses that police themselves. We can have a race to the polluted bottom, as you would have it, but that means we’re all sick and dead. Not a good solution. Let’s clean up our act and not have so many FLint, Michigans and Love Canals. Then we’ll negotiate for others to do that too. They said putting pollution controls on cars so we don’t have lead in our air will destroy the American auto industry. No, it just improved the health of Americans.

              1. John S, RE: “We primarily have the businesses police themselves …”

                So you want to live in a government controlled police state! Not me!

                Regulations work for a while, but then people and Global Corporations always find ways to cheat. I live in a state with so many laws and regulations on the books it would make you head swim :-) And most people and companies just ignore them, and no one does anything about it.

                And no one is advocating for a “race to the polluted bottom”. Regarding Flint and Love Canal, if you get your information from unbiased sources, you will be able to see many so called industrialized countries around the world that have putrid living conditions far worse than those two cases.

                What I would like to see is a plan for reducing pollution that is equitable to all countries. Seems as though a lot of people like to bash the USA these days, but they never have a good plan to change things fairly.

                Can you recommend a plan that doesn’t involve a socialist police state?

        2. >>> the one’s that do reduce their pollution will be at an economic disadvantage.

          Maybe somewhat, but they’ll be at a “health advantage”. (Yes, I realize air pollution is global, but local contamination is far more severe. How’d you like to breath the air in Beijing?.)

      2. Dr J,

        Yes, human beings have mucked the place up.

        Looking at things for water-only cleaning, I felt such relief when I mentally realized all of the products I would never buy again.

        Last year, I tried to figure out how to be zero waste and cleaning products are coming off my list.

        Grocery bags are gone.

        It seems like consumers will drive the change.

        Young people aren’t buying stoves anymore.

        Consumerism has caused so much of it.

        Corporate greed.

        When I was looking at steamers, I found 2 commercial quality steamer brands selling for much cheaper than the others and in both cases it was the companies that moral decisions to not do planned obsolescence and to not do exorbitant pricing.

        That is how our company thinks and how we operate but it is harder to be that way.

        I am so happy to have resolved cleaning.

        Food becoming more toxic is genuinely frustrating.

        1. By modest pricing, I don’t mean cheap.

          I might be only paying $20-ish per month for my steamer but there are a lot of months I will be paying it.

          What I mean is that it is stainless steel construction Italian made with a lifetime warranty and the heating element is not in the water.

          I saw it and wanted to hug the company owners and tell them that I love them.

          1. What I am figuring out about myself is that I feel so happy and so satisfied when i figure things out and understand things and can finally live simply.

            The complexity of figuring out how to live a simple life is astounding.

            And that is because of the invention of plastic and planned obsolescence and lying in advertising.

            Every once in a while you can still find craftsmanship.

            I paused and peered across the internet at how the Japanese made rice cookers are described.

            I didn’t buy one but it makes me happy that they still have special ones and it also made me happy that Bon Appetit and America’s Test Kitchen both recommended my old $20 rice cooker along with the Japanese made brands.

            1. I second Darwin! Please share the brand of steamer you bought. I find word of mouth is the best way to find great products versus dubious marketing by companies.

              Thanks!

          2. Deb, Can you post the brand name of the steam cleaner you bought? I’m always looking for ways to personally reduce pollution and keep the environment clean. That steamer sounds like a really good device.

    2. To be honest, I’d be concerned only if I drank matcha tea. According to this study

      ‘Taken together, our results suggest that drinking an average of five cups of green tea per day will not exceed the RDAs for the analyzed elements.’
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4762913/

      A significant amount of the heavy metal in tea is bound to the fibre and we trow away the actual tea leaf. Which appears to retain most of the heavy metals – only a fraction of which leaches into the infusion. However we consume the entire leaf in powder form … and thus ingest 100% of any heavy metals in the tea leaves….. when we drink matcha.

      Of course, all this applies to normally brewed green tea rather than overnight cold steeping. Even so, drinking two to three cups a day wouldn’t seem (to me at least) particularly hazardous even if it doubles heavy metal extraction levels?

      1. Thank you Dr J and Fumbles. Dr J, wise words, and it does feel overwhelming at times just trying to negotiate the mine field of our food supply. If money is power, then trying to avoid buying products that do the polluting is a start. I try to support transparency in product info where/when I find it.
        Fumbles, ty for your helpful post. It does make sense, and maybe I will try cold brewing for shorter times, say a half hour or something.

        Your information will certainly interest those who habitually throw tea into their smoothies. Really not a great idea.

          1. Can anyone put my mind at ease?
            —————————————————
            I’ll take a crack at that Liisa… and I’ll start by telling you about some recent research:

            … “and found several that could robustly protect mouse neuron mitochondria from three stresses known to harm mitochondria in Alzheimer’s: small, toxic clusters of the amyloid beta protein; the neurotransmitter glutamate, which can excite neurons to death; and peroxide, a highly reactive molecule that can be released from damaged mitochondria and go on to harm healthy mitochondria.

            The compounds with beneficial effects protected the neuronal mitochondria in some ways more than others, and evidently worked via a variety of biological mechanisms. For example, dyclonine, an anesthetic found in some sore-throat products, protected cultured neurons against glutamate and peroxide toxicity. Dyclonine also increased the energy production of healthy mitochondria as well as the activity of their host neurons’ synapses–connection points to other neurons. Dyclonine seemed so promising that the researchers put it in the water supply of live mice, and again found evidence that it powerfully boosted the health of the mitochondria in the animals’ brains.”

            https://www.eurekalert.org/pub_releases/2020-01/sri-neo010820.php
            —————————————————————————-

            As you can see, the above discovery (I’ve bought a few tins of Sucrets and suck on one a day ‘-) doesn’t solve climate change which is a product of our times, but the health discoveries are also a product of our times.

            Something as simple as taking a dyclonine laced cough lozenge may prevent us from getting Alzheimer’s or ALS or any of the other neuronal mitochondria insults.

            Like that old song says, we gotta accentuate the positive and not over-emphasize the negative.

              1. Lonie, I was thinking more of the radiation causing cancer.
                ——————————————————————————–
                Oh… o.k., I’ve got a link to something that might help alleviate your concerns about that. Specifically, the study is about radiation protection qualities of ginkgo biloba.

                “The aim of this study was to study the effect of ionizing radiation on apoptosis-related protein concentrations as well as the radio-protective role of Ginkgo biloba and Angelica archangelica.

                It was concluded that both antioxidants can be used as radio-protective agents in cases of ionizing radiation exposure.”

                https://www.ncbi.nlm.nih.gov/pubmed/22294442/
                ——————————————————
                I’ve taken Ginkgo capsules for forever, but have recently changed to liquid drops as I feel that is a better way to get it into my system via the sublingual route.

      2. I was found to have a toxic level of fluoride in my body due to using two organic tea bags/day. I now buy Pique tea crystals made from tiny, non-contaminated tea leave. Of course it’s pricey.
        I also have toxic levels of lead and thallium, The lead is probably from using old Corelle dishes. The only way to find out what poisons you have absorbed from our contaminated world is to pay upwards to $10,000 for functional medicine testing. I am waiting to find out what my new, regular doctor thinks about these test results – which his predecessor said were not needed.
        Friends, your food and water are poisonous. The road to recovery is long, expensive, and complicated. Good luck getting started. If you can’t afford a functional medicine doctor, start with searching the internet for doctors who give free information about diet, exercise, yoga, meditation, gut repair, sleep, and high quality supplements. Clue: most of us should get off grains, sugar, alcohol, and oils except olive (cold) and avocado. Read No Grain, No Pain by Dr. Peter Osborne. Humans should eat mostly organic vegetables and, if not vegetarian, ocean fish and clean meat. Today’s a good day to make a positive change!

        1. Gail,

          To quote Dr. Greger:

          “Unless one can access a time machine and teleport back to the days before the Industrial Revolution, fish will remain the leading source of many toxic pollutants.”

      3. AFAIK, Dr. Greger himself eats a teabag worth of green tea everyday and advocates for doing so. (The bottom of page 387 in “How Not to Die”.)

        1. Blair, I think you’re right. I picked up the idea of cold brewing from Dr Greger too, and thankful for it. I never really liked green tea until I tried cold brewed. Totally different, clean and refreshing tasting. In a perfect world I would find a tested, organically grown white tea or matcha and enjoy it every day.

  2. Frankly, I’ve never found matcha particularly appealing. I drink a cup of green tea every morning, using two tea bags as I like my green tea stronger than one bag creates. A small drop or two of maple syrup (I’m a Vermonter and it’s like mother’s milk to me) makes it perfect.

  3. Quick question: About to embark on using green tea extracts for preventative benefits. Respectful of EGCG. Supplement instructions stated 2-1000 mg capsules/day. Wouldn’t one/day be safer for liver and still grant the benefits of the compound?

    Just trying to be safe.

    Richard

    1. Hi Richard,

      The cited article (https://www.ncbi.nlm.nih.gov/pubmed/24862489) stated that the capsules the woman used contained 725 mg of a decaffeinated green tea leaf extract from Camellia sinensis in each capsule, according to the product’s specification. It noted adverse effects from that dosage, so it may not be safe to take even one of the 1000 mg capsules you have daily. This article recommends drinking actual green tea to reduce risks.

  4. OFF-TOPIC

    Deb

    You are interested in brain health and I came across this Chinese study which may be of interest to you

    ‘The change in mean serum DHA levels was greater in the intervention group (+3.85%) compared to the control group (+1.06%). Repeated-measures analyses of covariance showed that, over 12 months, there was a significant difference in the Full-Scale Intelligence Quotient (ηp2 = 0.084; p = 0.039), Information (ηp2 = 0.439; p = 0.000), and Digit Span (ηp2 = 0.375; p = 0.000) between DHA-treated versus the placebo group. In addition, there were significant differences in volumes of left hippocampus (ηp2 = 0.121, p = 0.016), right hippocampus (ηp2 = 0.757, p = 0.008), total hippocampus (ηp2 = 0.124, p = 0.023), and global cerebrum (ηp2 = 0.145, p = 0.032) between the two groups. These findings suggest that DHA supplementation (2 g/day) for 12 months in MCI subjects can significantly improve cognitive function and slow the progression of hippocampal atrophy. ‘
    https://content.iospress.com/articles/journal-of-alzheimers-disease/jad160439

    1. Tom,

      Thank you so much!

      Yes, I am very interested in topics like DHA.

      I know the debate rages on, but I do think it helps my brain.

      I say it more because when I forget to take it for a month or two and I notice a difference.

      The part of my brain that doesn’t trust supplements and doesn’t want to spend money on them wins sometimes, but DHA is something I believe I show brain improvement when I take it.

      1. Deb, this is something I posted above for Liisa. Thought it might be something you would want to know as it is a simple solution of taking a brand of throat lozenge that contains Dyclonine. Personally it has become part of my daily regimen (sucret lozenge each morning.)

        … “and found several that could robustly protect mouse neuron mitochondria from three stresses known to harm mitochondria in Alzheimer’s: small, toxic clusters of the amyloid beta protein; the neurotransmitter glutamate, which can excite neurons to death; and peroxide, a highly reactive molecule that can be released from damaged mitochondria and go on to harm healthy mitochondria.

        The compounds with beneficial effects protected the neuronal mitochondria in some ways more than others, and evidently worked via a variety of biological mechanisms. For example, dyclonine, an anesthetic found in some sore-throat products, protected cultured neurons against glutamate and peroxide toxicity. Dyclonine also increased the energy production of healthy mitochondria as well as the activity of their host neurons’ synapses–connection points to other neurons. Dyclonine seemed so promising that the researchers put it in the water supply of live mice, and again found evidence that it powerfully boosted the health of the mitochondria in the animals’ brains.”

        https://www.eurekalert.org/pub_releases/2020-01/sri-neo010820.php

    2. Mr. Fumblefingers,

      As always: But what else were the study subjects eating, drinking, and smoking? What is the test group compared to? Do we think the results would be different if the test subjects and controls ate a balanced whole food diet, didn’t drink alcohol or smoke cigarettes?

      Ah, those inquiring minds which want to know…

      1. Dr J

        It was a randomised, double blinded placebo-controlled trial.

        You’d have to read the full study to answer those questions and see what was and was not controlled for. Unfortunately, it is behind a pay wall.

        ‘Do we think the results would be different if the test subjects and controls ate a balanced whole food diet, didn’t drink alcohol or smoke cigarettes?’

        Speculation is free and intriguing but is there any evidence that the results would be different? It would be nice if they were but we have to consider the risk that it might just be wishful thinking to think so.

    3. That is quite a bit of DHA. Dr. Bredesen recommends taking it plus tumeric/curcumin before exercise to get the most benefit.
      Thanks for posting.

      1. Marilyn Kaye,
        My family physician does not recommend any omega supplements, but I did ask the neurologist this past summer about it. He said lifestyle matters, ie weight, exercise, sleep, diet (wfpb got a thumbs up), all of it counts. As for supplements, quality and dose are the important things… if the dose isn’t high enough he said I would be wasting my money. 2 gm minimum dha epa fish oil combined. Enteric coated.

        Dr Ornish has recommended minimum 2 gm fish oil since the 90’s.

        1. Barb, That seems roughly consistent with my Omega 3 Index results from Omega Quant. At the time, I had been taking 500-1000 mg per day of algal Ovega 3. Each 500 mg cap has 270 mg DHA & 135 mg EPA or 405 mg total. My dosing was not regular so I don’t know the exact amounts. Assuming it was roughly 50/50, then my total DHA/EPA would have been on average ~600 mg.

          My Omega-3 Index DHA/EPA % was 8.7% (anything over 8% up to 12+% was considered desirable/low risk; 4-8%, intermediate risk; less than 4%, high risk, according to whatever metrics they were using). My understanding is that a typical 1 g. fish oil pill would have ~ 300 mg DHA/EPA combined, so 2 grams would be about 600 mg total, not too far from my own estimate.

          Of course, these levels are much higher than Dr. G recommends.

          Here’s an Alzheimer’s research site and statement on DHA, I found interesting: https://alzheimer.neurology.ucla.edu/DHA.html

          1. Thanks gengo, this is one I have used in the past https://sealicious.ca/raspberry-lemonade/ I also have another one in the fridge that is 600 mg (1170 fish oil) total, and the directions say 2 x day.
            I wish I had read the studies with olive oil before I had my appointment lol. I take every oportunity to learn more and would have loved to hear his view on it. 1 liter per week was over the top though… I think we all agreed. 1 tbsp per day maybe….

    1. I searched and searched for some good studies for you, but only found this one
      https://www.hsph.harvard.edu/nutritionsource/food-features/tea/
      which says just what I discovered: ” Most research looks at the health effects of traditional teas, not decaffeinated…”
      However the article continued “…Decaffeinated tea may lose polyphenols that are associated with health benefits, depending on the processing method. Polyphenol content varies widely among teas even before the decaffeinated process, so it is hard to know the exact amount that remains. Regardless of decaffeination type, tea is still considered a healthful beverage choice.”
      Until more research is done, you may have to drink your decaf tea with knowledge that it IS healthful, although no clear answer if it works as well as caffeinated choices.

  5. Excellent Q & A

    It is so fun to see Dr. Greger live. I think I was right. Dr. Greger, you look much more handsome and personable and real in a natural setting. I say it because the videos having unnatural light and unnatural background is where the sense of being a caricature comes in.

    Watching you just acting natural in a natural setting was so nice, and you nailed it.

    I thought the sentence that the Adventists are the only Blue Zones that continues to be a Blue Zone is something that tells me that the young people have to say, “I am going to be the next Blue Zone.”

    https://www.youtube.com/watch?v=JxW4NiIEqj0

    1. Also, if you look at your older Q&A’s, your green shirt is the one that looks so friendly and bright against the room color and that might be what I am responding to.

      I went back and just loaded a blue shirt and white shirt and the green one is amazing with those walls.

  6. I use organic white leaf tea; tested for heavy metals. I’m curious if the white tea is as beneficial as green tea? I also eat the leaves every morning in my oatmeal.

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