Doctor's Note

Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. Check out the other videos which address carcinogens and putrescine. And there are 1,449 subjects covered in the rest of my videos–please feel free to explore them!

For more context, check out my associated blog posts: Mercury Testing Recommended Before Pregnancy, Harvard's Meat and Mortality StudiesDiet and Cellulite , and Tarragon Toxicity?

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. Check out the other videos which address carcinogens and putrescine. And there are 1,449 subjects covered in the rest of my videos–please feel free to explore them!

  • Thea

    I like that this video has the “game show” format that other videos have had. This format is one my favorite kinds, because it gets my brain working and it is fun.

    The two biggies, were clearly the ones to talk about. What also interested me, though, was how some of the other foods played out. For example, there were two cheeses: feta and blue. One was twice the amount of the other. (But maybe at that level, neither is significant?)

    Also, there was two kinds of alchoholic drinks: beer and wine with what looks to me to be very different results.

    Another interesting thing to me about these results is the two pickled vegies (assuming I understand what they are): kimchi and sauerkraut. They are both under 40, but look to maybe be about 20? Hard to judge by the video. Assuming that these numbers are per-serving and in some cultures, one might have more than one serving a day of these foods or combine these foods with others such as say blue cheese, sausage or wine, perhaps one should be careful of these other foods too – not just the canned fish.

    I’m just having fun with the video and making some observations. Nothing to get worked up over. Thanks.

    • Michael Greger M.D.

      You make a good point Thea. In fact, maybe this helps explain the kimchi finding? Check our my video: Is Kimchi Good For You?

      • Thea

        Dr. Greger: Thanks for reminding me about the kimchi video. I forgot all about that.

        Wow. So interesting! One video may very well explain the other.


  • Meha

    Now with Brazilian Portuguese subtitles:

    • Michael Greger M.D.

      Thank you so much Meha!

      • Leslie

        Does this hold true for raw sushi tuna?
        And how about raw shellfish?

        I am guessing for now the cooking and or canning process is
        what is causing the high levels of putrescine, no?

        Also wondering if you make it a habit of using soy sauce.

  • Michael Greger M.D.
  • Michael Greger M.D.

    For some context, please check out my associated blog post Harvard’s Meat and Mortality Studies!

  • Neal

    Miso soup is made from a kind of infusion of Bonito (a kind of tuna I believe) that is dried, smoked and fermented. (It’s actually an infusion of both bonito and a kind of seaweed called kombu). It is soaked, like a tea, in hot water and then removed. The remaining infusion is called “dashi” and it is combined with miso and green onions and a variety of other ingredients to produce miso soup.

    Does anyone know or have a feeling for whether it is bad for you in some ways? Is simply infusing bonito into hot water toxic in some ways? Would anyone care to speculate if there is no direct evidence?

  • Ronald Chavin

    Tuna fish contains LESS putrescene than any other food. The fruits that Dr. Greger strongly recommends are higher in putrescene than any other food:

    The big picture is that people who eat lots of fish and seafood have LONGER life expectancies than vegans in most studies.

    Putrescene appears to be relatively harmless. Meanwhile, spermine and spermadine appears to be greatly beneficial:

    • nonyabizzz

      Until you define exactly what constitutes a vegan diet and the criteria used for “most studies”, your ‘big picture’ assertion is baseless.

    • barbarabrussels

      I wonder what Dr Greger makes of these studies, I’m don’t speak medspeak, but your finds seem relevant. The only thing is that fish nowadays contains so many toxins that perhaps Dr Greger’s suggestion for b12 and omega 3 algae-derived seems like a safer alternative. I would advise you to search this site for ‘fish’ and watch the relevant videos.

      • barbarabrussels

        Oops, sorry, I wasn’t too clear there, I meant B12 supplements and Omega-3 supplements, the latter derived from algae. This for those on a vegan diet.

  • William Dwyer

    I found this reference, which echoes one of my concerns about the studies Dr. Greger cites:

    “Laboratory studies on the effects of BA [biogenic amines] face a number of methodological problems. Most studies have focused on the effect of individual BAs administered intravenously to laboratory animals or healthy volunteers, but these results are difficult to transfer to food intake since the intravenous response is several times higher than that obtained with oral administrations [87]. Neither are the results of physiological response studies in animals always transferable to humans.”

    In fact, there is now evidence that spermidine has health promoting properties.

    For one thing, it has been shown to ameliorate degeneration of the optic nerve, which can eventuate in blindness. Invest Ophthalmol Vis Sci. 2015 Jul;56(8):5012-9. doi: 10.1167/iovs.15-17142. Spermidine Ameliorates Neurodegeneration in a Mouse Model of Normal Tension Glaucoma.

    For another, supplemental spermidine prolongs the life of living organisms often used as models for longevity science. Spermidine is known as a molecule that activates a biological process called autophagy that is believed to be involved in most if not all lifespan-prolonging therapies. [Autophagy 2010] Spermidine is described as a “novel autophagy inducer and longevity elixir.” [Autophagy 2010] Inhibit autophagy and all living organisms age faster. [Cell 2011] While there are no human studies involving spermidine, centenarians are known to exhibit healthy levels of polyamines such as spermidine. [Rejuventation Research 2012].

    Finally, by far the richest food source of spermidine is wheat germ, which has more than twice as much as the next highest food source, which is soybeans. Dried beans in general have a lot. Are we to assume that wheat germ, soybeans and other legumes are potentially carcinogenic? If not, then what do we make of the studies Dr. Greger cites, suggesting that the polyamine spermidine in our diet is to be avoided or minimized?