Doctor's Note

This video seems like a departure from the last 5 videos, which describes an Ex Vivo Cancer Proliferation Bioassay, but those who've seen my full-length presentation Uprooting the Leading Causes of Death know that this all circles around in the end. I've touched on IGF-1 before in Daily Hormonal Interference and Meat Hormones & Female Infertility, but soon you'll know everything you wanted to about it (but may have been afraid to ask!).

For some more context, check out my associated blog posts: Eating To Extend Our LifespanStool Size and Breast Cancer Risk, How Do Plant-Based Diets Fight Cancer?, Animal Protein and the Cancer Promoter IGF-1, and Estrogenic Chemicals in Meat.

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  • Michael Greger M.D.

    This video seems like a departure from the last 5 videos, which describes an Ex Vivo Cancer Proliferation Bioassay, but those who’ve seen my full-length presentation Uprooting the Leading Causes of Death know that this all circles around in the end. I’ve touched on IGF-1 before in Daily Hormonal Interference and Meat Hormones & Female Infertility, but soon you’ll know everything you wanted to about it (but may have been afraid to ask!).

    If you haven’t yet, you can subscribe to my videos for free by clicking here.

  • Basskills

    How is this different from Human Growth Hormone for muscle building?

    • Toxins

      Its the same hormone actually. The supplement industry for bodybuilders has a very damaging impact on those consuming their products. Little do people know that most of the supplements they take is either useless or harmful.

  • SJS

    IGF-1 seems to be very closely linked to overall dietary protein intake…would be interested to get your thoughts on this..

  • Teresa Amo

    Can’t wait to hear the prevention part of this.

    • Noah

       Me too, I hope there will be some videos on what foods will contain or make the body produce more of this hormone.

  • Massimo

    I guess that in the next videos you are going to show that bovine IGF-1 is identical to human IGF-1, that it survives digestion, and eventually enters circulation to boost the endogenous levels of IGF-1. Which means, cow milk is the best way to promote cancer.

    • JenDiggityDirt

       I hope so. If not identical then similar enough that we cannot discount that cow milk hormone may affect us in similar way. I mean we ARE drinking a milk that is meant to make animals grow. We are animals. The only ones that drink milk into adulthood and the only ones that drink milk from another species, they say. I just can’t believe that if it were a good practice that nature would have just goofed and not made it a natural food for animals. We need to stop thinking we know so much more than what the natural world is screaming at us. I believe our bodies are BEGGING us to stop consuming dairy and the horrible end result of us ignoring them is disease. Animals aren’t as sick as we are in nature and surely much of that is the result of eating their perfect natural diet. We need to just eat our perfect natural diet. There is a bounty out there and dairy isn’t part of it.

      • Ginny


         Re.animals:  they are sick and die young ..because of the polluted environment man has created and because we keep moving their habitat. 

      • Mings

        Read Weston Price: “Nutrition and Degenerative Diseases” it can be found by googling the name of the book and Pottinger-Price.

      • Peakview

        Flawed thinking. Milk is simply not available to adult animals. That is why they don’t drink it. Would it make any sense for adult animals to feed each other? No. They need to get energy from external sources.
        Humans started using diary as soon as they figured out how to get the milk. Sounds pretty natural now. Learning how to make fermented diary products promoted rapid adoption of dairy for even those who are lactose intolerant.
        Dairy demonization has no legs except in our current days of adding in hormones and antibiotics. Take that away and dairy is an excellent food source.

        • VeganLondonMan

          “Would it make any sense for adult animals to feed each other? No.” Well what do you call an adult bovine animal feeding an adult human animal? Makes no sense, Peakview.

      • disqus_g7VMcXYmfs

        YEAH! But “Milk Does the Body Good” or better put: “Milk provides huge profits (at our expense) for the Food Industry” WHO has a huge pull in the political circles- so the truth, along w/ all the pink ribbon/fund raising/Big Pharma/Monsanto, etc etc- Aren’t really interested in our well being as they are in their profits- ALL at our expense. Wake up people- eat the way nature intended. It’s all just common sense.

    • Toxins

      Actually, the point Dr. Greger is going to make is that its the type of protein consumed that triggers our own liver to upregulate IGF-1 production.

  • Shane Jackson

    A little scary considering all the ads for various supplements in lifting and fitness magazines for IGF-1 precursors and such

  • Rhmentzer

    If IGF-1 promotes growth in children, does a vegen diet slow growth in children?

    • Toxins

      No, a high meat diet has the potential to put children at risk for early puberty, which puts them at risk for chronic illnesses later in life. Children have naturally elevated levels of IGF-1 in their body. Eating vegan does not hamper this level.

    • King Rocker

      No, very few children have died due to vegan diets, and usually these are those where it’s been given to them too early on.

  • Darryl

    An astounding chart comparing serum IGF-I levels in children with cancer with levels in age and gender matched controls. From Badr, Mohamed, et al. “Insulin-like growth factor-1 and childhood cancer risk.”Oncology Letters 1.6 (2010): 1055-1060.

    • guest

      This truly is shocking! I couldn’t understand the article very well. Did they say whether the cancer promoted the levels, or were the levels already high from lifestyle or supplements? I know zinc increases igf-1, and some parents worry their kids need vitamins and minerals so they give them multi-supplements which have zinc in them.
      Also, a lot of older men take zinc supplements, ironically to help keep their prostate healthy. Its frustrating how something can be helping and harming at the same time.

      • bob

        So using hgh secretagogues (amino acids, etc.) at an older age would possibly + correlate with cancer incidence? Or is there a reduced correlation at older ages? At one time was selling an IGF-1 supplement….might still do so.

    • Harriet Sugar Miller

      Does insulin or glucose trigger or contribute to IGF-1 production?

      • Darryl

        There’s a weak association with carbs in observational studies. For the most part IGF is how a surplus of complete protein is signalled.

        On cell membranes, there are insulin receptors, IGF receptors, and hybrids of the two, and they all effect similar downstream pathways. Oncologists use the abbreviation IIRF (insulin and insulin-like growth factor I receptor family), and some think excess insulin signalling through the IIRF links metabolic syndrome, obesity and cancer risk. Some bodybuilders take advantage of these hybridized pathways by injecting insulin to increase muscle growth.

        • Adrien

          “Some bodybuilders take advantage of these hybridized pathways by injecting insulin to increase muscle growth.”

          Yes and it can be very dangerous, some have ended in a wheelchair by simply trying.

          Listen from 7min to 8.

          Personally I used to eat dates after workout. And it worked fine.

  • skipstein

    I tried to post this on another topic but got it under the wrong caption
    to my question, so here goes. I am 67 year old make and was diagnosed
    with prostate cancer (Gleason=8) four years ago and immediately switched to a strict vegan nutritional base. I’ve been an avid fan of Nutrition Facts (post them on my Pinterest site daily). For the first time I had my IGF-1 level checked (my doctor didn’t have a clue as to why) after reading/hearing about the beneficial impact of a low IGF-1. Mine is now 105 (very low?) and my testosterone is over 800; just as the doctor’s video mentioned! But is it low enough to combat my prostate cancer (recent PSA=7 up from 5.8 4 months ago)). Most of my blood work is terrific (HDL=71 LDL-74, Triglycerides=38).

    It is really hard to develop targets for some of these tests and I
    want to better understand how I should proceed. Current literature is
    all over the place and none/few address prostate cancer and nutrition.

    Tell Dr. Greger thanks for his guidance.

    Skip Stein

    • Codite

      My husband was diagnosed with prostate cancer and we actually ‘lowered’ his PSA by eliminating sugar from our diet. We observed a no white trash diet and his PSA went down almost 2 points. No flour, no sugar, no potatos, no fruit, no milk. It is rough for the first couple of weeks, but the cravings go away and the result was great. My naturalpath had at least 5 former prostate cancer patients who were ‘cured’ by diet alone. Food does make a difference.

  • 2378

    Just watched a doco on BBC on this, apparently all you need to do to half your IGF levels, is have 2 days a week where you eat only 1 meal for that day.

    Some people even go as far as every second day.

  • BETH


  • hulkimaniac

    Guess what!? Eventually youre gonna get old and freaking die regardless!!!!

  • Kelsey Byrne

    People – IGF-1 is also used for many other good things and growing is one of them. If you want to sit around on the couch and inject IGF-1 and think you’re going to grow then yes you’re probably going to grow a tumor. If you are working out and breaking your body down to build it up then IGF-1 becomes a way to recover and help with damaged areas. Also if you have a headache do you take an entire bottle of aspirin? Of course you don’t because you don’t want to die. The same should be said for anyone looking to take IGF-1. Like any drug prescribed from a doctor or supplement bought from a store research and education can help you safe guard yourself from ignorant mistakes. Again if you are breaking your body down seriously then IGF-1 helps in all sorts of great ways to shuttle nutrients to damaged areas. When it comes to cancer there are many variables but IGF-1 is obviously one link of a much larger chain and we shouldn’t demonize it just because one study shows it caused cancer. What about all the people smoking cigarettes or have extremely poor diets?

  • J

    This is pure pseudo scientific alarmist.

    While drinking rBST milk can increase ORAL IGF-1 intake, it has been proven over and over again that this doesn’t increase SERUM BLOOD levels of IGF-1. IGF-1, as well as other proteins, amino acids and peptides, are rapidly denatured in the GI track. rBST milk does not raise SERUM BLOOD levels of IGF-1 because it never passes the gut. At any rate, binding proteins will inhibit unbound IGF-1 is under 20 minutes. Other BPs effectly “tie up” 99% of the body’s IGF-1 at a given time. Hormonal feed back loop much?

  • Mary Lynn

    Taking creatine revs up IGF-1. Will this increase your chances of getting cancer?

  • Benni

    Do you think a change in diet can help someone with acromegaly? My boyfriend has tried but hasn’t been able to completely cut out dairy. He doesn’t eat meat or drink milk but still eats cheese and eggs. His heart doctor told him to add fish back into his diet recently. Any recommendations?

    • Joseph Gonzales R.D.

      Hi Benni. I do not see much in the literature. Dr. Greger seems to only have one video that briefly mentions acromegaly. I think a healthful diet is important regardless of the condition at hand. I would listen to his doctor, but you may want to ask about plant-sources of omega 3’s, as they could be an alternative if he is trying to avoid fish.

    • Mary

      Much of fish is now high in mercury. I would check out what fish is safe to eat.
      In my opinion, eggs are one of the healthiest foods you can eat as long as you have no problems with it. Preferably not from crowded, diseased chickens, either.

  • Bobby Valens

    I’m a 27 year old male and I currently have testicular cancer but have not received treatment (chemo/radiation) for this. I typically eat a vegan diet, but here’s the tricky part. I also love to bodybuild; my supplements currently involve: creatine, glutamine, and a concentrated functional protein. The functional protein actually works as much as 25x the regular dose of whey protein, all in one scoop, which means the protein heavily increases the igf-1 within my body; Should I be avoiding these supplements completely? I would highly appreciate any feedback and info on combatting this cancer with proper nutrition.

    • docboat

      1. Get treatment
      2. Do not substitute nutritional treatment for cancer treatment – they both go together

  • Mita Sharpe

    I was reading one of those informercials that sound like nutritional advice until you get to the end when they offer a guide to lose weight, freshen breath. make you pretty and whiten your teeth valued at gazillion dollars all for the ridiculous (their word) amount of $19.95. This one, which I copied and pasted :
    The World’s First All-Natural IGF-1 Boosting
    Weight Loss And Body Rejuvenation System
    Designed To Give You Sustainable, Enjoyable And
    Lifestyle-Friendly Fat-Burning In Just 22 Days!
    I decided to research IGF-1 and found this website that warns about the very same thing Dr. Jonny Bowden is touting! He even answered a question about taking supplements by saying that he’ll talk about it once you purchased his program. Now he does offer a 60 day money back guarantee so he must believe in what he’s selling, right? Any feedback is appreciated. Thanks.