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Is Type 1 Diabetes Triggered by the Bovine Insulin in Milk?

The tight correlation among countries between the incidence of type 1 diabetes in children and cow’s milk consumption didn’t account for Iceland. Indeed, studies correlating dairy intake in children and adolescents with the incidence of type 1 diabetes deliberately excluded the Icelandic data. Why? Is it because of genetics? Perhaps, yes and no. The people of Iceland are similar genetically to other Nordic countries, but their cows are not. As I discuss in my video Does Bovine Insulin in Milk Trigger Type 1 Diabetes?, there are two main types of the cow milk protein casein: A1 and A2. Icelandic cattle, who “have been isolated from interbreeding with other cattle breeds for over 1,100 years,” are unusual in that they produce mostly A2 milk, which may explain the lower incidence of type 1 diabetes in Iceland.

Unlike A2 casein, A1 casein breaks down into casomorphin, which has opioid properties that may alter immune function, perhaps increasing susceptibility to infections that may themselves trigger type 1 diabetes. That’s what’s in the milk from the classic black-and-white patterned Holstein cows, who make up about 95 percent of the U.S. dairy herd and much of the global herd—A1 casein. This issue has even caused dairy boards to begin taking out patents on methods for selecting “nondiabetogenic” milk to avoid triggering of Type 1 diabetes. Indeed, looking only at A1 casein consumption certainly restores that tight linear relationship between milk intake and type 1 diabetes and you can see at 1:47 in the video.

These so-called ecological, or country-by-country, studies, however, primarily serve to suggest possibilities that then need to be put to the test. For example, a study was designed where hundreds of siblings of type 1 diabetics were followed for about ten years and found that those who drank a lot of milk did have about five times the risk of coming down with the disease, too. By the mid-1990s, more than a dozen such studies were done.

Overall, researchers found that early cow’s milk exposure appears to increase the risk of type 1 diabetes by about 50 percent. Those data were enough for the American Academy of Pediatrics to decide that “cow’s milk protein may be an important factor” in the initiation of the process that destroys our insulin-producing cells. The organization went on to say that the avoidance of cow’s milk protein may reduce or delay the onset of type 1 diabetes. As such, the American Academy of Pediatrics emphasizes that breast milk is best and, for those at higher risk of the disease, strongly encourages the avoidance of products containing cow’s milk protein that is intact, as opposed to hydrolyzed formula where the milk proteins are broken up into tiny pieces.

Typically, hydrolyzed formula is given to children with dairy allergies and could potentially make it less risky, but we don’t know until we put it to the test. Based on the population studies and meta-analyses of antibody studies, which suggested that “cow’s milk may serve as a trigger of Type 1 diabetes,” a pilot study was initiated the following year. Researchers wanted to see if babies at high genetic risk for the disease would be less likely to develop antibodies that would then attack their own pancreas if they drank hydrolyzed casein—that is, casein that was chopped up. The hydrolyzed formula did seem to reduce the appearance of at least one autoimmune antibody, but not two or more, which is much more predictive of the development of the disease.

Nevertheless, that was enough for the investigators to embark on the ambitious Trial to Reduce Incidence of Diabetes in Genetically at Risk, also known as the TRIGR study. This multinational, randomized prospective trial involved randomizing thousands of newborns across 15 countries. In 2010, preliminary data suggested the hydrolyzed formula may have helped, but they didn’t quite reach statistical significance, approximately meaning there was greater than a 1 in 20 chance the findings could have just been a fluke. Indeed, when the final autoimmune antibody results were published, the special hydrolyzed formula didn’t seem to help at all.

The researchers only looked at a special group of children, though—ones who were at high genetic risk with diabetes running in the family—whereas the great majority of children who get type 1 diabetes do not have any afflicted close relative. Perhaps most importantly, however, as the researchers themselves emphasized, their study wasn’t designed to test whether cow’s milk is or is not a trigger for the disease. Instead, it aimed to analyze the potential effects of the hydrolyzed casein formula. Maybe it’s not the casein, though. Maybe it’s the bovine insulin.

Insulin autoantibodies—antibodies our body produces to attack our own insulin—often appear as the first sign in prediabetic children. “Because cow’s milk contains bovine insulin,” around the same time researchers were looking into casein, another team “followed the development of insulin-binding antibodies in children fed with cow’s milk formula.” They found significantly more antibodies to bovine insulin in the cow’s milk formula group compared to the exclusively breastfed group, who may have only been exposed to cow proteins through their mom’s breast milk (if their mothers consumed dairy). Furthermore, the bovine antibodies cross-reacted with human insulin, potentially being that caught-in-the-crossfire cause triggering at least some cases of type 1 diabetes.

Of course, we can’t know for sure until we put it to the test. Researchers ran another randomized, double-blind trial, but, this time, tried a cow’s milk formula from which the bovine insulin had been removed. And, indeed, without the bovine insulin exposure, the children built up significantly fewer autoimmune antibodies. What we don’t know yet is whether this will translate into fewer cases of diabetes.

You may also want to check out:

For more on the concerns with cow’s milk exposure in infancy and childhood, see:

I’ve developed a six-part series on the role of gluten-free, casein-free diets in the treatment of autism:

What’s The Best Baby Formula? Breast milk!

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:


Michael Greger M.D., FACLM

Michael Greger, M.D. FACLM, is a physician, New York Times bestselling author, and internationally recognized professional speaker on a number of important public health issues. Dr. Greger has lectured at the Conference on World Affairs, the National Institutes of Health, and the International Bird Flu Summit, testified before Congress, appeared on The Dr. Oz Show and The Colbert Report, and was invited as an expert witness in defense of Oprah Winfrey at the infamous "meat defamation" trial.

39 responses to “Is Type 1 Diabetes Triggered by the Bovine Insulin in Milk?

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  1. Seems true . For some reason I disliked milk and my parents could only get me to drink it unless I added chocolate to disguise the taste. I also disliked meat of any kind as a young child. I was diagnosed w T1D before my 12th birthday in 1969. My parents were more concerned that I get nutrients and I never ate meat or drank cows milk after diagnosis. My haplotype is not a typical Disbetes one although it is has an autoimmune pattern. Lisa

  2. Saying breast milk is the best formula is a bit of a snarky answer because some mom’s don’t produce enough milk or have other issues. What is the second best formula?

    1. I am interested to know too! If infants do not access to breast milk (and others’ breast milk), should they take cow formula or soy formula or etc?

      1. While we should all recognize that breast milk is best, if there is absolutely no way to have the infant breast fed, even with donated milk, there are still options including soy formula such as While vegan formula has yet to launch in the U.S., you can find great dairy-free soya based formulas here: Enfamil ProSobee, Similac Soy Isomil, and Earth’s Best Organic® Soy Infant Formula are a few options that you can easily find at your local stores

        Here are some articles that will give you options:

        These resources will help when and how to transition from the soy formula to plant-based nutrition with focus on plant-based whole foods and water:
        Best of health to the fortunate baby who will be raised with the best diet for growth!

    2. I truly believe T1D is absolutely correlated to milk. My oldest was born borderline Galctosemic which showed up on his newborn screening. When the screen came back, his pediatrician had me stop breastfeeding and switch him to soy formula immediately. We later learned after a genotype was performed on his Dad and I, that he had a low Galt enzyme because we had a low count ourselves. He has an asymtomatic mild form of Galactosemia called the Duarte variant. Since his enzyme count is low, he doesn’t break milk down and digest it as efficiently as a typical person but is really no worse off than his Dad or I. His pediatrician had us withhold all dairy for his first year. He began milk products at a year old and by 2.5 he was diagnosed with type 1 diabetes. I had read a few things when he was newly diagnosed regarding a theory that milk proteins can sometimes escape the gut and cause an inflammatory response and that a lot of diabetics are also vitamin D deficient. If this were true it made perfect sense to me why someone who does not break milk down as others, who lived in the northern hemisphere, is blonde haired and fair skinned, was diagnosed during the winter months, and was not exposed to milk until after his first birthday would develop diabetes and why vitamin D would be lacking.

  3. When studies require using things that have been modified (cows milk with bovine insulin removed, for example) isn’t there a significant risk that the modification process will have effects other than just the one intended?

  4. I find this very interesting. My father died of type 1 diabetes in 1955, I was 3 and my sister was 1. She developed type 1 diabetes at age 9 and died at age 11, 1964. I was diagnosed as type 2 diabetic in the 90’s. I now take insulin and am well controlled. I used to drink lots of milk until allergies stopped me consuming milk in the 80’s, too late to reverse the damage done by the milk. I am now making the transformation to a vegan whole plant based diet. Let’s see if I can get off the Lantus. (The nephrologist has found diabetes in my kidneys so who knows what this life style change might do.)

  5. Can eating plant based ever get rid of auto-immune problems? I suddenly developed Lichen Planus in my mouth. I am 79 years old. Is there anything I can do to get rid of it besides taking steroids?

        1. It’s usually eaten in salad but as a herb it can be included in rice or legume dishes too.

          You could also make a tea out of the leaves and stem.

          1. I threw away buckets of purslane last summer that grew in my gardens. Next summer I will eat some! I found a great weblink with recipes. But I wonder what I can do for Lichen Planus right now!

    1. I see one of knowledgeable commenters already gave you the NFO video I’d suggest you view. As a nurse I’d press your doctor a bit about other treatments besides steroids. Check this basic article out if you haven’t already research Lichen Planus. While steroids are the usual recommended treatment, there may be other approaches that will help you. You need to work with your doctor and monitor of course, but
      you certainly have a right to consider all treatment options.
      As you will read Lichen Planus sometimes is cleared by the body without treatment, but that may not be a reasonable approach for you now. Certainly some auto-immune problems, such as arthritis are not only improved but actually resolve after adoption of a whole food plant based diet. Certainly improving your immunity by eating this way will help with treatment. Best of health to you in dealing with this.

  6. This blog post is very uplifting… that is, it shows that science is aware of the problem and if science recognizes the problem, there is a very good chance it can fix it.

    Thinking back, Dad usually only bought Jersey or Guernsey cows for us kids to milk. I remember only one Holstein and I don’t think we kept her very long.

    Dad wasn’t what you would call a touchy-feely father, but it appears now that he more than made up for that in intuitively providing what was best for his family without having the best practice approach laid out for him.

    1. I asked this when a previous video on A-1/A-2 was posted… What about goat milk instead of bovine milk? Wouldn’t that make a good replacement in infant formula?

      1. Lonie- From what I gathered, it’s both the non-human proteins and non-human insulin that are the problems. When we’re younger our bodies might identify the insulin and proteins in milk as foreign and produce antibodies against them. Our insulin is similar to other mammalian insulin so those antibodies go on to attack pancreas cells leading to T1D.

        This would suggest that goat milk wouldn’t be an ideal alternative. Soy milk would probably be the way to go assuming breast milk wasn’t available.

        1. Ryan, thanks for the reply.

          My thinking that goat milk may be a safer substitute, especially for newborns who cannot nurse, is the fact that many people who cannot drink cow’s milk can easily consume goat milk.

          Obviously there is a great difference between the two.

        2. This would suggest that goat milk wouldn’t be an ideal alternative.
          Ryan, not disputing your intuitive theory, but so many times something that seems intuitively correct can be found not to be correct due to even one small change. Obviously cattle and goats are two different animals (two stomachs vs one.) For that matter, even sheep and goats are different.

          I was hoping someone had seen some research on goat milk that might clear up the similarities or dissimilarity of the different types of milk.

            Excellent find Tom!

            This could make a good follow-up subject for D R Greger since milk is the subject of many of his recent videos.

            Offering goat milk evidence as an alternative to bovine milk, especially in infant formulas would be very helpful in putting new mother’s at ease, knowing there is a solution to the suspected problem.

    2. Nice that you have genuine respect for your father.

      I can’t name very many touchy-feely fathers from the old days.

      My father has started to become emotionally sensitive in his old years. It still genuinely surprises me. I think it is because his wife had a stroke and he has had to become a caretaker.

      Happy Thanksgiving, Lonie.

      Hope you had a good day.

      I made a curried sweet potato and butternut squash dish. The process showed me how broken my brain still is and I almost gave up, but I finished it, and I have almost never succeeded at finishing dishes for the past several years, since my brain issues. I used the stove and this is the second time I succeeded using the stove. I never succeeded when using the instapot.

      But I honestly almost melted down just trying to do it.

      The nice part was at the end of the night the person whose house we were at said, “I really liked the spices with the sweet potato. I would never have thought curry would go with it. It was really good.”

      I still came home a little tearful. My brain really does incapacitate me.

      Someone talked about the date and I realized that I had no idea what year we were in. Mentally, I thought maybe 2021 or something.

      But, I am succeeding at work and succeeding at organizing my house and I guess I am just going to be thankful that people liked the dish.

      They won’t know that I couldn’t follow the recipe and ended up making my own up and had to go to the grocery store 3 times.

      Still, I have a lot to be thankful for.

      1. I succeeded in bringing dishes 2 holidays in a row is the proper attitude to have.

        I have to think that way and thank God for that before I go home and have to wash the dishes.

        My kitchen tells the tale.

      2. Deb, if I didn’t (virtually) know better, I would think you are a prevaricator. ‘-)

        That is to say, anyone who can write and reason as well as you can should have no need to be overly concerned about your brain health.

        I think what we have here is a person who demands excellence and even rocket scientists (probably) do not achieve that.

        I was talking with a friend at coffee last week and the subject turned to his wife. He said she (being a highly trained nurse) can tell you anything you want to know about medicine and art, her former occupation and her long held passion, painting. But, he stated that when it comes to common sense she is severely deficient.

        He said a similar thing about a Dr. he golfed with at the local country club. Many attest to the surgeon’s skills in the operating room along with his attending knowledge how to proceed. But he also noted that the Dr. was not the sharpest knife in the drawer when it came to playing dominos or even the best way to attack a golf course.

        Let me say this about my friend… he is a retired insurance agent and a successful one at that. But I have to stifle a smile when he refers to the term cartridge as “cartlege”… and some other misnomers I can’t readily recall.

        But he does have common sense and I suspect, a slightly above average IQ. I suggested his wife and the surgeons’ whole life was wrapped up in their interests to the point of not paying attention to much else, whereas he and I talk about a wide range of topics and show an interest to learn about many varied new things.

        Remember when people used to tie a string around their finger to remind them of something? Writing this reminded me of something I need to check on so I put one of those wide rubber bands an my wrist to remind me to check it again later. ‘-)

        What I’m sayin’ is, my own brain is improved over past years but there is still room for improvement. But I thank serendipity that it is the brain I have rather than some normal brain… (not to the point of Abbe Normal, but yet not normal in the average sense of the word) and that keeps me striving to have a better brain, but not to the point where I am not grateful for the level I am at.

        Maybe in your case, solving your sleep deprivation will change the way your neurons fire?

        Anyway, please accept this rubber chicken post as part of your meatless Thanksgiving. ‘-)

        1. Lonie,

          Thanks for sharing.

          You made me laugh.

          Yes, I could give examples of things like that.

          Including the fact that some of the lowest IQ people I have met in my life were so very intelligent. When I became a Christian, it was a mentally retarded man who helped me understand the Bible. He was so “simple” minded.

          Typing that makes me laugh because he used to pray things for me like that I would work for Walmart someday and I still laugh because I have to pray harder than he does and that was a very difficult thing because he had a near-perfect sense of time and details and once he got something in his mind he didn’t let go easily.

          I am working hard at this brain repair process.

          I am hoping that you are right about the sleep thing. I have slept a few extra hours each night since I got the oversized throw from Eddie Bauer.

          But I will tell you that sometimes my brain deficits become very obvious.

          Other times, I can focus on the list of things that have improved and there is such a big list of things that got better.

          I spend hundreds of dollars and it takes days every time I try to cook a dish to bring to a party.

          I should have just ordered a few of Mamma Sezz mashed sweet potatoes or picked up a pie but I am trying to get better and it means doing hard things.

          1. it was a mentally retarded man who helped me understand the Bible. He was so “simple” minded.
            Maybe he’s just an Occam’s Razor kinda guy. ‘-)

      3. My father has started to become emotionally sensitive in his old years. It still genuinely surprises me. I think it is because his wife had a stroke and he has had to become a caretaker.
        I just re-read your post Deb and the above caught my eye.

        I became a care taker for my Mother many years ago… she could do for herself but after almost burning down the house when leaving a pan of grease on the stove that caught fire, she asked me to move back home. And during that time I was looking after her I became much more empathetic.

        She has been gone for more than a decade now and I have since re-balanced to a more healthy empathetic/objective ratio.

        I think your assessment of your father is spot on.

        1. Lonie,

          I know that they have started deleting my comments and I won’t be back here ever again. I am leaving.

          I know that my brain is too broken to do these types of processes and I will never be back even to read your response, but I do want to say goodbye.

          I am not going to be online anymore.

          I have learned a lot here and I think my science and nutrition days are over, but I will not go back to drinking milk.

          I will move onto something else local.

          1. I know that they have started deleting my comments and I won’t be back here ever again. I am leaving.
            Deb, are you sure? I think Tom felt that his comments weren’t posting sometimes. If your comments are truly being deleted, I hope someone higher up will look into this and reverse such an error (In my opinion.)… and even apoligize.

            I can’t believe anyone in their right mind would remove one of the gems from the crown.

  7. Hi,

    I wanted to know whether there is any known method of protection against Type1 DM. In particular, if someone has tested positive for an Antibody (say GADA). Is there any way to protect yourself from developing Type 1 DM?

    Thanks very much.

  8. The short answer is that vitamin D supplementation has been shown to decrease the risk of Type I DM in children, and theoretically, avoiding animal product consumption, especially bovine milk and meat, may reduce the risk as well. I have seen anecdotal evidence that LADA (very similiar to Type 1 DM) might be reversed on a strict, optimal lifestyle (WFPB, optimal sun exposure and optimal exercise, no substance abuse)

    This link discusses the vitamin D link:

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