Doctor's Note

If these pollutants are particularly found in seafood, are those that eat fish at higher risk for diabetes? See my last video, Fish and Diabetes, and my next, Pollutants in Salmon and Our Own Fat.

For more on dioxins, see:

For more on PCBs, see:

These pollutants may also play a role in our rising epidemic of allergic diseases. See Alkylphenol Endocrine Disruptors and Allergies and Dietary Sources of Alkylphenol Endocrine Disruptors.

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  • Leslie

    Are there any particular plant-based foods that are more likely than other plant-foods to contain these contaminants? How about nuts and seeds, that compose of high-fat? And how about, say, pumpkin seeds from china, would they accumulate more of these pollutants than, say, fruits from china? Is the fat content of the food source what is vital in allowing for the accumulation of these pollutants?

    • Darryl

      Plant-based foods generally have tiny amounts of dioxin like compounds compared to animal products. Freshwater fish, butter, cheese, hot dogs/bologna and breast milk are particularly contaminated.

      Accidental dioxin contamination of vegetable oils can occur. Outbreaks of choracne have been reported from rice oil processing-plant leaks in Japan, and storage of olive oil in plastic containers previously used for “other purposes” in Spain.

      The regional and diet studies of breast milk contamination may offer some indication of the regional contributions to exposure. The good news is dioxin and PCB concentrations appear to be falling in developed countries since their bans in 70s. The bad news is PBDE flame retardants (with most exposure from house dust) in serum is still pretty high, and also associated with diabetes

  • Beetsbeansbutts


    Is it more the obesity or is it more the high intake and storage of these persistent chemicals?

  • Harriet Sugar Miller

    Saturated fats are associated with insulin resistance (
    and POPs concentrate in fat. To what degree does this explain the reason for the problem?

  • Hasn’t diabetes been a problem for the rich and obese going back to Hippocrates? I assume there were not much in the way of POPs back then.

    I don’t dispute POPs may increase risk, but cause all risk? I am skeptical.

    BTW, did the researchers adjust for the fact that mostly poor African-Americans are forced to live in the neighborhoods near toxic dumps, people who often have no choice but to consume calorie dense, nutrient poor foods?

    • Joe Caner

      Well, you have probably heard the phrase “Mad as a hatter” haven’t you? Workers contracted a neurological disorders from mercury exposure while the making of hats. Many of the patent medicines of the 19th century were made with mercury as well as from other toxic compounds and elements. Who do you suppose were wealthy enough to avail themselves of these products? The same people who were also wealthy enough to eat in excess.

      Perhaps, there is has always been environmental toxic component as part of the diabetes disease cascade. Exposure to toxins is not a new phenomenon, but generalized obesity is.

      • Many of the patent medicines of the 19th century were made with mercury as well as from other toxic compounds and elements. Who do you suppose were wealthy enough to avail themselves of these products? The same people who were also wealthy enough to eat in excess.

        Right. But that would be co-morbidity, not necessarily cause and effect.

        • Wegan

          They still put mercury in vaccines, stu-upid. ( not you, them)

          What if the pollutants are causing the obesity?

          • Joe Caner

            It is unconscionable that the pharmaceutical industry uses a known neurotoxin like thimerosal as a preservative for vaccines. Few individuals would make such a decision. It a sort of thing that would only be formulated by a system that views the natural world and people who inhabit it as externalities, and places profits over people.

          • Wilma Laura Wiggins

            I like to see out of the box thinking such as this.

        • Joe Caner

          No causal relationship was established, but there is a strong epidemiological relationship between toxicity and diabetes established by the study sited in today’s video. The high correlation between diabetes and toxicity may help explain why there is an increase incidence of a diabetes as well as all cause mortality from the increased consumption of meat. Modern industrial meat production practices with its associated higher levels of bacterial loads and increasing levels environmental of pollution coupled with the overall increase in meat consumption has turned a foodstuff that was perhaps relatively benign, to one that contributes to many of the most common chronic diseases suffered today.

          I brought up mercury as an example of a common toxin. People have cooked in copper pot. They have cooked in ceramic containers surfaced with high lead glazes. My point is that environmental toxic insults are nothing new.

  • DStack

    To Dr. Greger and anyone else with thoughts:

    I’ve noticed my acne flares up whenever I lose weight.
    I just switched over to a high-fruit diet and lost a few pounds and my acne has been terrible, whereas before it was fairly stable on a McDougall-style diet. I don’t think it’s the fruit causing this (from what I hear from other people it should have the opposite effect).

    Could there be a connection here? I used to eat terribly, and I wonder if the fat stores remaining on my body could still be harboring pollutants and toxic chemicals.



    • Darryl

      POPs in obese individuals during weight loss

      Surgery-induced weight loss was associated with a gradual and significant increase in the serum concentrations of POPs measured in obese patients … At 12 months, the mean serum concentrations of pollutants were increased by 38%, 46%, and 48% compared with basal levels.

      • DStack

        So that would signal that the body burning fat does release toxins. The real question is whether or not that would cause acne flare-ups.

        Thanks for the input!

        • Joe Caner

          Perhaps you could try adding some ray broccoli and cilantro which are both great detoxifies to you all fruit diet, and see if this doesn’t improve things for you.

      • Leslie

        Could a too-low body fat percentage be a detriment to a vegan in regards to the human body having no place/a reduced amount of place to store toxins ingested, and maybe these toxins then just circulate around, needing a storage receptacle of fat? I’ve heard it said that there are actually some beneficial aspects of having a healthy, (and sometimes a bit more than average fat) for various health aspects. I can’t help but think that there is a paradox going on here, in this regard, at times. Sure, someone ingests some dioxins and they get stored in the body for a long long time, but if that person has such a low body-fat percentage, it seems like the body might be compromised to properly deal with some of the toxins, no? Can a proper fat-storage facility/ability by the body actually being considered safe, I guess is what I am asking you?

        I’ve struggled to put on a healthy amount of body-fat, no matter how much I eat, vegan or not. And I know some vegans who are ultra-low-body-fat, way too low, and even though they are not ingesting the likely sources of dioxins and other pollutants, are their (and my!) body’s still compromised due to unhealthy low levels of body fat? Thanks so much, I hope this is of interest to you. I find the possible paradox fascinating.

        • No one is completely fat-free.

          • Leslie

            Fat-free is not what I am saying. A very low/too-low/unhealthy level of low body fat is what I am concerned about in this regard. Yes, everyone has some fat, but a suboptimal amount may jeopardize the human body’s ability to properly store toxins until proper elimination. I just don’t know what the medical science says in this regard. But I have seen reports of some of the healthy benefits of an adequate level of body-fat, when opposed to a suboptimal level.

          • Devin Wiesner

            Hi Leslie, the NIH defines a normal Body Mass Index (BMI) as that between 18.5 and 24.9. Check your BMI, I have pasted a link below. A recent review of studies did find that those outside of this normal range had higher rates of morbidity. On a personal note I was happy to find that despite being 6 feet tall and 145 pounds, I am considered normal. This does surprise me as I cannot find a shirt that fits me. I digress, despite being on the thin side I do not concern myself with weight, I just focus on eating a diverse diet of fruits, veggies, seeds, nuts, roots, leaves…fungus.

          • pining

            What recent review do you have in mind?

          • Devin Wiesner

            The Journal of Epidemiology and Public Health, March 28, 2014…The review did note that malnourishment, drug or alcohol use, smoking, poverty and mental health issues are often contributing factors to being clinically underweight and therefore, perhaps, somebody’s weight may be a valid biomarker. Though for somebody adherring to a Calorie Restriction Optimal Nutrition diet, I would argue that this type of study is not applicable. This article covers the study and provides a link to the journal:

          • pining

            Thanks, Devin. I can’t easily access the article, but the general caution about reverse causation at the low end is something that I’m already familiar with, though I also understand that thin people don’t do so great in some forms of major surgery, for example.

            This relation between BMI and morbidity seems like a pretty good choice for an article that appears to take a didactic tone. Linear regressions are very easy and can feel endorsed by authority depending on your education, but they are obviously not always a good choice and seem to be a frequent stumbling block in some parts of the literature on health over the lifespan.

        • These toxins are metabolized and excreted primarily by the liver and kidney. If they accumulate in the fat before they are excreted it will lengthen the time it takes to rid the body of these substances. They are already slowly excreted since many of these are ringed carbon molecules with chlorine molecule(s) and are unlike anything that naturally occurs. This helps explain why it is so hard for our bodies to metabolize them. The half life for humans for dioxin and has been estimated to be 6-7 years. I’m not aware of any good studies for “normal” folks as the studies I have read are in patients who have had industrial level exposures (i.e. large amounts). Exposure to carcinogens is best minimized whether you are thin or not.

        • Devin Wiesner

          Hi Leslie, in all sincerity I would question your concern about a “healthy amount of body-fat”. Healthy to me, means having a strong immune system, low levels of inflammation, relatively consistent levels of energy and avoidance of chronic illness….If one of your concerns is the metabolism of pollutants check out Dr. Gregers video on “Plants versus Pesticides” and start eating organic ginger and citrus every day. I add both, peel and all, to my daily smoothie. Oh, be sure that the Ginger is not from Asia as it may be contaminated with lead (There is a lawsuit by the state of California related to this). Eating a healthy, diverse, nutrient rich diet protects your body, increasing your liver’s ability to metabolize and excrete potentially toxic chemicals. There are so many studies that support this.

          • DStack

            I have to agree with Devin, I don’t believe it’s necessary to have excess fat on my body. I’ve been pretty slim for years now, but I’m happy to see the fat I put on in adolescence finally going away, and I can’t see how that would be unhealthy, seeing as I’m eating 4,000 calories a day of whole foods, mainly fruit and veg!

    • General advice for populations of patients are important but there is individual variation. Dr. Greger has done a number of videos on dairy and its effect on acne. A quick pub med search shows several abstracts implicating simple carbohydrates to acne. Since fruits consist of glucose, fructose and sucrose or table sugar which are all simple carbohydrates. Since the McDougall style diet was working I would change back as your new approach isn’t working for you.

      • DStack

        Thanks for the input. I’ve only been eating this way for 3 weeks, and my acne situation wasn’t consistently good while on the McDougall diet anyway, so I’m going to give it some time. If it continues to be this bad even after my weight stabilizes I may switch back to eating less fruit. I think maybe once my body has time to adapt to the new lifestyle it might improve anyway.

    • Are you consuming dairy? whey protein? A dermatologist from Germany explains how those foods can cause acne:

      • DStack

        No, by McDougall-style I meant completely vegan, and I’ve been doing that for nearly two years. I did consume a lot of dairy when I was younger, though. My acne was even worse back then.

        • I’m just throwing this out there–an interesting anecdote, but doesn’t address the problem systemically:

          My son has found that applying green tea compresses helps his skin. You just make some green tea, then apply it with a spritzer or with cotton after a shower .

          • DStack

            Thanks, I’ll give that a try!

  • marge

    Every time I put berries on my cereal I am reminded of the video that says that milk prevents the absorption of nutrients of berries. Is it the same for other milks, such as soy or almond milk?

    • Marge, which video is that? Mind providing the link?

      • marge

        Video: Nutrient Blocking Effects of Dairy on this site.

    • Wilma Laura Wiggins

      Pretty sure that applies only to animal milk.