Doctor's Note

For more on mercury contamination in fish:

And check out my other videos on fish

For more context, see my blog post: Mercury Testing Recommended Before Pregnancy.

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  • sarahharmony

    i wish i had found this before i fell pregnant – am 8 months along now but better late than never! Am really enjoying your website – thankyou.

  • 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. And check out the other videos on fish. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

  • Janjan

    Saw you speak at the NHA convention, really enjoyed your style of delivering a very important message. I’m here at the Regency health spa detoxing from sugar and aspartame.

  • why i can’t see any discussions anymore!

  • gary

    Understood that we should limit or eliminate fish intake, but what about the argument here?

  • thank you for this

  • Ilana

    They still have mercury in vaccines. Is that a concern? I assume you are a proponent of vaccines, that the protection outweighs the risks? (Even though vaccines are not technically vegan.)

    • shayneo

      No. The amount of methylmercury in vaccines is so low the harm can’t even be calculated. There have been plenty of studies and no evidence of harm has been found.

    • Mercury is always a concern and has to be balanced against the benefit. You can insist on getting immunizations from a single dose vial. The single dose vial do not need to have a preservative in them.

  • Mark

    isn’t an injected mercury meaningfully more toxic than mercury eaten in fish? Doesn’t every dose of mercury accumulate in the body?

    • No. It has to do with the dose. Organic mercury is very well absorbed by the GI tract. The amount of injected mercury has to be compared to the amount in food such as fish. Also consuming fish which is the greatest source of mercury in the diet comes along with other contaminants such as dioxin, insecticides and even drugs. You might view videos on fish to see the extent of this problem. Mercury is best avoided.

  • Ray

    Hi Doc,

    I was just wondering if you exercise any scientific skepticism when reading the literature for your videos? Do you wait a little while to see what comes out of the post-publication review of the articles? Just because there is a single study with a certain result does not mean that it reflects the direction of the literature. Just curious as to what methods you use.

  • matt

    Hi Doc

    I was just reading about thimerosal. The mercury in thimerosal is an inorganic ethyl mercury as opposed to the methyl mercury in tuna. Isn’t ethyl mercury processed more easily by the body. If that is the case, is it even fair to compare thimerosal and tuna?

  • Claire

    Enjoying every topics as they are presented by Dr Greger with finest and a real passion. Any insight on tinnitus relief? Thank you for any suggestions that might reduced tinnitus by even a decibel. Claire

  • Mary

    i have a vaccine related question…i am the caregiver for my sister who is mentally retarded. I am generally opposed to the flu vaccine for myself and any otherwise healthy individual. (i have been whole food, plant based for over 3 years). I believe that prevention is the way to go. Having said that, I feel very conflicted about not vaccinating my sister. She eats my diet when at home but spends time with other family, as well as in the community, where she engages in a SAD diet. She lost her spleen in an accident and that is what causes me worry. My question is wouldn’t the susceptibility she has to contracting the flu also indicate that she would be at higher risk of having a bad reaction to the flu vaccine??? She had a fairly recent bout (Jan 2014) with sepsis where she was in critical condition. Thank you for any light you can shine on the subject.

  • Jonathan

    Dear Dr. Greger,

    Do you believe there are situations when vaccinations are advisable?

    Some people who identify with natural medicine claim that vaccinations often cause more harm than good, such as as leading to autism. While there have been scientific studies which maintain that vaccines are not a cause of autism:

    How does a lay person go about sifting through the perspectives and research in order to have an accurate understanding of this topic?

    • Kasai Dragoness

      Vaccines have not been proven to cause autism. A recent study has concluded that the leading cause of autism is actually oxygen deprivation before birth, in the third trimester (which was my case; I had an umbilical cord wrapped around my neck).

      But even so, I don’t see how autism could be worse than getting Measles or Smallpox. Lets weigh the risks here;

      Communication deficits, issues in social interaction, and repetitive or restricted behaviors and interests VS. Almost certain death.

  • Robert Luhrs

    Too bad the sound is so low can hardly hear it. Will share anyway, the info is still very valuable.

    • Thea

      Robert: re: low sound
      FYI: If you look to the right of the upper video, you can see that this video comes from “volume 2” of the DVD series. Videos from early DVDs have this low volume problem. Happily, whatever technical problem had been involved, has been figured out and all new videos have good volume.

      I just thought you would want to know that the problem affects more than just this one video, and is a known one.

      I’m glad you see some good value with this video. Me too!

  • Chiki Chan

    To quote Dr. Jack Wolfson: “please show me the study that found 69 doses of 16 vaccines do not cause cancer, auto-immune disease, and brain injury.”
    Must get informed about vaccination from reliable sources, like:
    There is a huge difference in harm when one ingests mercury and when it is injected directly into blood. It is sad and disruptive to see doctors without any expertise interpreting data.
    Learn more:

    • guest

      I agree. What independent studies show that vaccinations are safe? I can tell you since their inception: NONE. End of story this is a follow the money story. The racket protection surrounding the Big Pharma is quite extraordinary.

    • Lasma

      Do You think there are vaccines that are still worth having?

      • Cody

        Hi I am a volunteer for Dr. Greger. I believe Dr. Greger will be posting videos regarding the benefits and risks of vaccinations in the near future (upcoming few weeks to months). Stay tuned to see what his science-based recommendations are! I’m very curious to see what he’ll have to say!

        • Lasma

          Thanks! Will wait to see :)

  • Drug manufacturers label their products will all the active and inactive ingredients. They do not similarly label their immunization agents. In addition, some immunization agents are made with the help of animals that are kept in captivity. The animals may be slaughtered. The animals may be made to suffer. Information about how the immunization products are made is often quite difficult to come by. Unless I have information that an immunization product is made only from plant products or mineral products, I have to assume that the product in not suitable for someone who wishes to avoid complicity in causing harm or suffering to animals, that is, not suitable for a vegan.

  • Dorothy Vidaña

    Dr. Please help. My son has been diagnosed with Acute Promyelocytic Leukaemia. its been about a month since our diagnosis. They want my whole family to get the FLU SHOT. I have not been vaccinating any of my kids for the past two years since i have gone vegan and honestly i need some professional guidance. i research but hardly anything shows for his disease and vaccinations or flu shot. please help. where do i turn?

  • Graham

    The CDC spells this differently. See

  • Vege-tater

    OT but the “take me to a random video” option keeps taking me to this same video only.