Doctor's Note

I recently covered eggs and regular (type 2) diabetes in my video Eggs and Diabetes.

More on advanced glycation end products in Glycotoxins and Avoiding a Sugary Grave.

The heme iron in animal products is one of the toxic components the meat industry is trying to develop strategies to mediate. See Meat Additives to Diminish Toxicity. More on heme versus nonheme iron in Risk Associated With Iron Supplements.

What else has the Harvard Nurses Health Study shown us? See:

For other cautionary pregnancy tales, see:

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  • Annie L

    I have reason to be concerned about my thyroid and I am being told that strawberries should be eliminated/limited in the diet, as they contain a substance that can compromise the thyroid. Same goes for spinach. Is this true? Strawberries….are there science-based documents that verify this? And would gently steaming spinach for a few minutes eliminate completely any thyroid concerns?

    • JanetPlanet

      Dr. Greger talks about these “goitrogenic” compounds in a blog post, and how to be sure to get enough iodine in this video

      • Annie L

        Yes, I have read this and watched the videos, but I do not see or hear any mention of strawberries being an issue for some people, yet the guidance I am getting from elsewhere is saying that strawberries can be an issue. I am hoping Dr. G can look through the science to see if this is in fact correct.

        • Darryl

          That’s from some 1948 studies on iodine-131 marker accumulation when coingested with foods, recapitulated in this 1957 review. Spinach & strawberries had a “moderate effect”, rutabaga was the only food with a “marked effect”.

          DH and I had a discussion on goitrogens in comments here. From what I could gather, its not just about the iodine: some combination of genetics, perhaps infection, selenium deficiency, iodine deficiency, and goitrogenic foods are all implicated in places with endemic goiter.

          • Adrien

            Hey Darryl, I got a question for you. Could radioactive iodine be a concern from consuming kelp or kelp tablet ? I’m reducing my salt intake using low sodium salt with 66% potassium chloride and 33% sodium chloride but it’s not iodized, so I started taking kelp tablet (thanks btw for your answer to my question on supplements, it help me big time!). A biologist friend told me that there is chance that macro-algae can be radioactive due to their metabolism (meaning they store lot of iodine and don’t differentiate the radioactive one from the not) and due to their origine (where they come from). According to him, the north sea and the english channel is heavely polluted by years of dumping radioactive waste from boat by the nuclear industry, and they still do it from the shore in France (not to mention Japan). I guess it’s difficult to find where the kelp come from. But do we have data that test supplement for Iodine 131 ? I have the one you talked about: 500 Tablets 150% the RDA, 225mcg iodine for 4,49$. Thanks !

          • Darryl

            Iodine, whatever its source, will have some radioisotopes, and two are of interest in the environment.

            I-131 has a short half-life (8 days) and its accumulation in the thyroid is a concern in the immediate aftermath of nuclear fallout. Having high iodine body stores and consuming uncontaminated iodine sources (sea kelp, potassium iodine tablets) in the weeks/months after these events (ie, living downwind of Chernobyl) will reduce uptake of the I-131. Given the short half-life, I-131 is not much of a concern long after the release, less than 1 part in 100 trillion of whatever release remains after a year, its undetectable after two. It would similarly decay in old kelp products.

            I-129 is a product of uranium fission (both natural and man made) with a long half-life (16 million years), and ocean levels have risen about 10 fold from atmospheric fallout and 1000 fold in some ocean basins near fuel reprocessing plants. The highest basin levels are about 1 part in 100 million parts of the main isotope of iodine, and is been scientifically useful in measuring ocean currents. Its not a significant health concern, as its concentrations are still minute and I-129 is less than 1/600 millionth as radioactive as I-131.

            Naturally occuring polonium-210 utterly swamps man-made radionucleotides in the sea. Like cosmic rays, its just part of the background, and at low levels could even be beneficial.

          • Adrien

            Great details, thanks you Darryl.

          • DH

            Thanks Darryl. My impression from that discussion was that you had searched high and low for an article that ranks various foods by goitrogenic activity and couldn’t find one. Is that still true? Obviously people in the west don’t tend to eat much cassava or bamboo…

            I decided not to limit my cruciferae but to steam some and leave other meals raw. I think the balanced approach is best – active anti-cancer compounds but not enough goitrogenic activity to knock out the thyroid. Of course, everyone’s threshold for the latter will differ, and much depends on the other factors that you mentioned. Since I don’t do routine TSH testing on myself, it is virtually impossible to know how much dose makes the poison here. Do you have any thoughts on that?

          • Darryl

            I gave myself a low-cost blood panel (there was a 40% Christmas sale) out of curiousity about my iron, D, CRP, and lipids, and TSH was okay (2.47 uIU/mL), but not great (< 2). This is in the context of a very high raw cruciferous and relatively low iodized salt diet. I'm hoping that adding the sea kelp pills, just started recently, will help by next year. Otherwise, having all one's blood numbers in hand is motivational. “How do I get my CRP lower”, “How do I get A1c under 5”, “My, my kidneys are amazing”. Worth it for health geeks.

          • Adrien

            I’ve done a blood test recently (11/13/13) ! May I share some result ? First, I tested many things in my blood. I even ask for homocysteine (60€ for it) and IGF-1. I come up with 2 asterisk (meaning out of range) one for “Degree of anisocytose (IDR)” that if I understand well is the shape and/or size of my red blood cells. At *11,8% (range 12,0-13,6) previous test: 12,6% (06/26/12). I’m not concerned a lot since I don’t have any symptoms of anemia. The second asterisk is for cholesterol. Titled “Exploration of lipid abnormality”. Total cholesterol: *0,87 g/l Triglycerides: 0,81 g/l HDL: 0,36 g/l LDL: 0,35 g/l (Starch based). Previous test: 1,12 g/l Triglycerides: 0,62 g/l HDL: 0,48 g/l LDL: 0,52 g/l (Raw food). I feel that I’m heart attack proof having the cholesterol of rural chinese because I eat like them more than a lipid abnormality. Vitamine D is fine with occasional supplements: 25OHD 33,5 ng/ml. (30-60) Last year without supplements: 19,7 ng/ml (I plan on taking more often). Vitamine B12 with supplements: 288 pmol/l (141-489) Last year without supplements: 124 pmol/l. Homocysteine: 10,17 µmol/l. One thing that I don’t understand is my Folates (Vit B9): 20,0 nmol/l (10,4-78,9) Last year: 24,4 nmol/l. I think this is weak regarding the fact that I ate Kale and Kidney beans two times a day for a weak or more before the test. But it may explain why my Homocysteine is 10 and not 8. IGF-1 eleveted: 298,5 ng/ml (I’m 25 years old) but I think I mess up the test by consuming lot of soy milk the day before.. My blood was tested at noon on an empty stomach without breakfast. I think it’s overall great. Any thought, anybody ?

          • VegAtHeart

            Can you please explain why you think TSH < 2 is would be great? Also, how is a very high raw cruciferous and relatively low iodized salt diet expected to affect the numbers? I am assuming we are talking normal range (0.3-5.6 MU/L), why should going < 2 be better?

          • Darryl

            A blood test reference range is usually the the range of values that 95% of the population falls into. This study discovered administering T4 to patients with “high-normal” TSH (2-4 uIU/mL) lowered their cholesterol, supporting the existence of a subclinical hypothyroidism with tangible harms, and numerous citing papers argue for a narrower reference range.

          • VegAtHeart

            Thanks for this explanation. I am also in a similar boat, consuming little added salt and quite a lot of cruciferous vegetables.

            I found some interesting points on iodine in this National Academies Press book.

            Being from Canada, I found it particularly interesting that:

            “Iodized salt is mandatory in Canada and used optionally by about 50 percent of the U.S.

            “Estimated iodine intakes for Canadians are in excess of 1 mg/day (Fischer and Giroux, 1987).”

            “The Tolerable Upper Intake Level (UL) for adults is 1,100 μg/day (1.1 mg/day)”

            1 mg/day vs 1.1 mg/day seems like a rather tight margin, doesn’t it?

            Another interesting point was that:

            “Deficiencies of vitamin A, selenium, or iron can each exacerbate the effects of iodine deficiency.”

            A bit confusing was the way that subclinical hypothyroidism was defined, which appears to depend on a T4 remaining constant:

            “Subclinical hypothyroidism is defined as an elevation in TSH concentration while a normal serum thyroid hormone concentration is maintained.”

            As far as I could see, they didn’t seem to specify a TSH range for subclinical hypothyroidism

          • VegAtHeart

            FYI: iodine content of commercially available seaweed varies greatly.

          • Darryl

            AFAIK, only the Nature’s Plus KI has a reasonable supplemental dosage (150 µg), and its 9 times as expensive as the standardized sea-kelp product I ended up with. Most KI pills have doses suitable for nuclear fallout protection (32-120 mg), but not for daily supplemention.

          • VegAtHeart


            Btw, based on a recent book chapter reviewing the literature, it seems that the association between mild subclinical hypothyroidism (TSH < 10 mU/L) and disease states is quite unclear.

    • I would find it hard to believe that eating moderate amounts of strawberries and spinach will cause difficulties with thyroid function. If you stick to a varied whole food plant based diet you should be okay. That said folks with symptoms suggesting low or high thyroid should work with their physicians as they may need treatment.

    • Veganrunner

      Strawberries. Can’t say I have ever read or heard anything about them. And as a person who is hypothyroid (controled with medication) I pay attention. Have you found any good studies out there to confirm? I eat a lot of strawberries and haven’t noticed anything myself.

      • Annie L

        I have not been able to find studies but there are several online thyroid websites that issue warning regarding strawberries, peaches, and some other fruits. I see no reason why they’d just be making this up – no agenda. I may email them to find out what they are basing their statements on.

        As an aside, I am finally admitting how tired I get when I eat raw kale. It is like my immune system gets run down. Maybe it is the thyroid-effect of raw kale. Spinach does not do this so much. But kale, the stuff drains my energy in an instant. I’ve heard from others who claim they get exhausted and weak after raw kale. Maybe it has nothing to do with a thyroid affect, but i’ve heard “kale and thyroid” mentioned together many times.

        • Veganrunner

          Annie are you actually hypothyroid? Or are you thinking it’s thyroid? The thyroid doesn’t actually make changes quickly. When meds are changed it takes many weeks for the TSH and T3 and 4 to adjust.

          The only thing that has ever affected my numbers is when I got an expresso machine for Christmas and went from drinking black coffee to drinking a latte. The milk (ca+) interferes with synthroid absorption. I was given the choice of continuing with the latte or increasing my medication. I gave up the latte.

  • Plantstrongdoc M.D.

    Suggestion for a new label for meat and eggs: WARNING: May be teratogenic

    • DH

      Yes, I agree. And this was a beautiful video. How many pregnant or pre-pregnant women know about this? Probably very little, simply because very few read scientific journals. I am glad that this information has now been conveyed to the public. Thank you, Michael.

  • Mitch

    OK, I’ve recently become convinced to adopt a vegan diet–it only took a SECOND MI to adequately convince me–I’m a slow learner. This may be elementary to those of you with more experience in the plant-based diet world, but is there any data on those fruit-and-vegetable washes that purportedly remove a large fraction of pesticide residues that contaminate non-organic produce? Are there any specific brands that are more effectiv than others? Any hints on methodology for use (e.g. soaking instead of just rinsing), etc. I know this is somewhat obsessive, to convert from the SAD to a plant-based diet and suddenly worry about pesticide residues when it was only recently that I loved to eat out at Fatburger without a care to saturated fat, cholesterol, and environmental toxins, but if you’re going to do it, you might as well do it right…

    • Veganrunner

      I was 99% organic before going vegan. Doesn’t sound crazy to me. If cost is a factor stick to the Dirty Dozen and Clean 15. You can get the lists on the internet.

      Cheers to cleaning out those arteries in 2014!

    • JacquieRN

      Never too late to take steps toward better health, Mitch! As to you question, there have been several studies on effectively removing pesticides and “germs” (micro-organisms) from produce. I will name a few here for you.

      In 2000, at the Connecticut Agricultural Experiment Station scientists compared pesticide removal methods on 196 samples of lettuce, strawberries and tomatoes. Some were treated with either a 1 percent solution of Palmolive or a fruit and vegetable wash. Others were simply rinsed under tap water for a minute. They found tap water “significantly reduced” residues of 9 of 12 pesticides, and it worked as well as soap and wash products.

      It appears as though water temperature was not important but friction was. “The mechanical action of rubbing the produce under tap water is likely responsible for removing pesticide residues,” scientists state.

      For those teeny tiny germs, rinsing produce with a mild solution of vinegar, about 10 percent may be the best. In a University of Florida 2003 study, researchers tested several types of disinfectants on strawberries contaminated with E. coli and other germs. They found the vinegar mixture worked best reducing bacteria by 90 percent and viruses by about 95 percent.

      Therefore, Mitch your best bet combine the 2: to remove pesticides and germs, is to rinse produce with a vinegar solution, then wash with tap water for at least 30 seconds.

      Have fun learning and eating!

    • Thea

      Mitch: Just to give you some moral support: You may not be the fastest turtle on the block, but you certainly learn faster than some people who would rather die than make a change. So, good for you!

      I love how you are diving in whole-potato to your new found diet. JackquieRn and Veganrunner both gave great answers. I would also say: you really do have to put things into perspective. Don’t get to the point where you feel like you can’t eat anything. Here’s a quote from one of Dr. Greger’s articles that I think helps with perspective:

      “A new study calculated that if half the U.S. population ate just one more serving of conventional fruits and vegetables, 20,000 cases of cancer could be prevented. At the same time the added pesticide consumption could cause up to 10 extra cancer cases. So by eating conventional produce we may get a tiny bump in cancer risk, but that’s more than compensated by the dramatic drop in risk that accompanies whole food plant consumption. Even if all we had to eat was the most contaminated produce the benefits would far outweigh any risks.”

      So, go ahead and follow Jacquie’s great info if you want and/or Veganrunner’s points about the Dirty Dozen and Clean 15. But if that gets to be too much, just enjoy your fruits and veggies however you get them. That’s my 2 cents.

      Good luck!!!

  • Ronald Chavin

    In this video, Dr. Greger describes to us yet another reason why people who eat eggs and people who eat pork have even worse all-cause mortality numbers than people who eat beef, people who eat chicken, people who eat turkey, and people who drink high-fat milk. Meanwhile, people who drink low-fat milk have the same all-cause mortality risk as people who don’t drink any milk. People who eat cheese have a slightly better (lower) all-cause mortality than people who don’t eat any cheese, probably because cheese contains vitamin K2/MK-7 and vitamin K2/MK-8, both of which remove unwanted calcium from our arteries. People who eat yogurt have an even better (lower) all-cause mortality than people who eat cheese. People who eat legumes (especially soy) or fish have the best (lowest) all-cause mortality:

  • Bill Hampton

    Is the natural sweetener in sugar harmful or is it just the concentrated
    carbohydrates? Some fifteen years ago I seen on the nightly news that
    scientists had found a way of separating the sweetener from the
    carbs. Supposedly, Splenda came about due to this process. Is the
    process of separation causing Splenda to not be good for you, or is
    it that the sweetener of sugar that is harmful?

    • Ed

      Table sugar is a single molecule: sucrose. Sucrose is a carbohydrate and a sweetener. There is no separate sweetener in table sugar. Splenda is sucralose, which is modified sucrose: some of the hydroxyl groups have been substituted with chlorine atoms.

  • Tan


  • Arnav Batra

    During pregnancy, a healthy and balanced diet is so much essential for the fetus and mother.

  • Madasyn Foltz Carns

    Some of your blogs have mentioned eating soy. Until recently I’ve only read negative things saying it’s so unhealthy (most likely competitors sponsoring those rumors?). Working my way to veganism, I’m trying to find recipes to replace eggs and tofu keeps popping up. I’m currently nursing and would like to know if there are any risks associated with eating (non gmo) soy while nursing and what’s the facts of nutrition for fermented vs non fermented?

    • Thea

      Madasyn Foltz Carns: Those are good questions. I’m aware of that anti-soy or only pro-fermented soy arguments out there. There is a *ton* of information on this site about soy. I would highly recommend just taking some time to go through the information. No one *has* to eat soy, but traditional soy products give us some great variety and wonderful recipes/dishes. There’s no reason to limit yourself unnecessarily.
      As a very high summary, I will say that my take-aways from NutritionFacts has been: 1) 3-5 servings/day of traditional soy products is healthy. Traditional soy products are: tofu, tempeh, edamame, soy milk, and miso. Note that fermented vs non-fermented is not an issue. 2) some of the health benefits of soy only show up if someone has been consuming it all their lives, especially before puberty. (So, keeping soy in your diet with the little one around would be a good thing.) But don’t take my word for it. You can find all the science to back this up on this site. Here is a good place to start, the topic page for soy:
      On a related topic: You can definitely find some great tips for eating while pregnant on NutritionFacts. But I have some suggestions for good quality information that is more global/complete. VRG (vegetarian resource group) has some great info for pregnant women as well as children/families. Here is the main topic page for families: Especially check out: Another great resource is the book Becoming Vegan, Express Edition by Brenda Davis and Vesanto Melina. Both authors and the book are recommended by Dr. Greger and they have an entire section on diet during pregnancy. An other sections for feeding kids which may come in handy in the future. PCRM (Physician’s Committee for Responsible Medicine) also has some good info in this area.
      If you have any other questions about how switch your diet, let us know. :-)
      Hope this has been helpful.