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Truth from the Dairy Aisle: Is Milk from Cows Receiving rbST Safe for my Family?

Today’s guest post comes from a dear friend of mine, Dr. Katie Schoenberg. Katie and I overlapped during our undergrad years at Cornell, but I didn’t actually meet her until we worked together in the Nutrition Lab at Smithsonian’s National Zoo, the first job out of undergrad for both of us. We bonded over analyzing desert tortoise urine and freeze-dried sea urchins (yes, really), and we had enough fun that we both stayed in science! Katie went on to earn her M.S. at University of Maryland and her Ph.D. from Cornell University, where she is currently a postdoc. She’s also a new mom to a beautiful 11-week-old daughter.

I invited Katie to write a guest post for ScienceofMom a while back, and lucky for us, she agreed. Katie’s research is focused on dairy cows, so I asked her what she thought about the safety of milk from cows treated with rbST. Being a stellar scientist and a conscientious mom, I knew I could trust her to give us the low-down on rbST. I’m especially grateful to Katie for putting this post together during her maternity leave, between diaper changes and feeding her baby girl. Her answer to this question may surprise you, and I look forward to hearing your thoughts about how you make food-buying decisions for your family.

Truth from the Dairy Aisle: Is Milk from Cows Receiving rbST Safe for my Family?

By Katie M. Schoenberg, Ph.D.

I have a B.S., M.S., and PhD in Animal Science and study the nutrition and metabolism of dairy cattle.   Recently, I gained a new title:  Mom.  Throughout my pregnancy and during the first 11 weeks of our daughter’s life I have enjoyed combining my zeal for the scientific method, my scientific expertise in pregnancy and lactation, and my newly acquired non-fact-based (though hormonally driven) motherly instinct.  This has persuaded me to revisit my own truth on an issue that I have thoroughly researched in the past:  the safety of the use of recombinant bovine somatotropin (rbST, also referred to as growth hormone or bGH) in the dairy cows producing the dairy products we consume.  As a new mom, now responsible not only for making healthy choices for myself but also my child, would I feel the same way about the safety of rbST?

Dairy cows, gathering ’round for a balanced meal.

Let’s begin with a brief introduction to the lactation cycle of dairy cattle.  Just like human moms, bovine (that’s a fancy word for cows) moms start producing milk when they give birth.  For about the next 10 months, a cow will produce milk that ends up in your grocery store dairy case.  Then, she’ll take a couple of months off to prepare for the birth of her next calf, when the cycle begins again.

All cows already have bovine somatotropin in their bodies.  After decades of scientific research, scientists recognized that cows supplemented with additional somatotropin produce on average 10-15% more milk every day1,2.  This reduces the number of cows and the amount of land, water, and resources needed to produce the same amount of milk3.  From a farmer’s (and consumer’s) perspective this is a positive in terms of business and environmental impact.

Cows that are given rbST (approved and used commercially since 1994) receive an injection of 500 mg (slow release) once every 2 weeks beginning around 9 weeks into lactation.  This recombinant somatotropin (ST) is a hormone produced by the same process used to make insulin for Type I diabetics:  recombinant bacteria.  In essence, the gene to produce bovine ST is engineered into bacteria that generate the hormone, which is then harvested, purified, and packaged.  The fact that the bacteria are producing the bovine form of the hormone has an important implication:  The bovine form of ST is NOT recognized by receptors in the human body.  This means that even if you injected yourself directly with a shot of rbST, it can’t have a biological impact on human cells.

That’s what rbST is and what it does for the cow, but how does it affect the milk that you and your children ultimately consume?  In 1985 the FDA determined that milk, meat, and other products from animals that have been given rbST was safe for human consumption.  The FDA continues to revisit the safety and efficacy of rbST regularly4,5.  The FDA and other agencies such as the National Institutes of Health6 stand by rbST as being a safe and effective tool for dairy farmers to use to enhance the productivity of their dairy cattle.

The use of rbST is safe, because it does not change the composition of milk in a biologically relevant manner.  In fact, there is no laboratory test that can tell whether milk came from a cow treated with rbST or not.  This is the reason that the “hormone free” labels say “our farmers pledge” rather than “guaranteed.”  There are several summary reports on the compositional differences in milk, such as the one published in the Journal of the American Medical Association in 19907.  All cow milk contains bovine ST, no matter how the cows are managed. Cows administered rbST at levels 6 times the dosage given to cows today causes a slight increase in ST in milk7.  However, recall that rbST is species-specific and is not recognized by the human body.

There’s another reason why I’m not concerned about a little bit of rbST in milk: The rbST hormone is a protein.  When ingested by mouth, it is digested and broken into constituent amino acids in your GI tract, just like every other protein eaten, and therefore results in zero impact as a growth hormone.  Even if it did survive digestion, your body wouldn’t recognize bovine ST, because its structure is only recognized by receptors in the cow.

This leaves two main arguments against the use of rbST8:  1) Increases in the milk concentration of insulin-like growth factor-I (IGF-I), another hormone regulated by ST; and 2) Increases in incidences of diseases such as mastitis (infection of the mammary gland) in dairy cattle.

Milk from cows administered rbST has been shown to have up to 2-fold higher levels of IGF-I9.   Unlike rbST, IGF-I, is not species-specific, so at first glance, this may be concerning.  However, IGF-I makes up only 0.00003% of milk proteins, and like all other proteins it is also broken down by digestion.  In addition, you would have to drink 1L of milk to equal the amount of your own IGF-I present in the saliva that you swallow on a daily basis6.  Furthermore, cows administered rbST have milk IGF-I concentrations within the normal range based on individual and day of lactation variation (1.27 – 8.10 ng/mL)10.  There are also several other studies which have shown that rbST administration doesn’t affect IGF-I concentrations in milk and that concentrations mirror the normal pattern of IGF-I secretion in cows not receiving rbST10.  For these reasons, I’m not concerned about IGF-I in my milk.

Lastly, I will touch on the effects on the health and wellbeing of the cows only briefly as ultimately this may be a social issue (vs. a health issue related to our children).  Use of rbST on farms does not lead to increased incidences of health problems in dairy cattle.   One study found no difference in the incidence of mastitis infections between cows that were or were not treated with rBST11. In another study, observation of over 1000 cows showed no significant effects of rbST administration on cow health, nor how long cows were in a herd12.  The biology of how rbST works demands that cow health and nutrition must be of the highest standard in order for rbST to increase milk production.   With poor cow health and nutrition, the farmer is throwing away money administering rbST.  I would argue then, that herds that use rbST improve the health and wellbeing of their animals to take advantage of the efficiency improvements from rbST.

The bottom line is that this mom has come to the same conclusion as this Dr. had previously:  that milk and dairy products from cows treated with rbST are safe for my children and me to consume.  On top of that, I like the environmental benefits of using rbST!  So, given the choice I’d rather consume milk from cows that have been given rbST.  Unfortunately, my opportunity to do that in the grocery store is unnecessarily limited these days due to fears that don’t seem to stand up to scrutiny… such a shame!

Author Bio: Dr. Katie M. Schoenberg is a postdoctoral research associate in the Department of Animal Science at Cornell University.  She works with – what else – cows! Katie and her husband have a spunky 11-week-old daughter, who tolerates their obsession with Cornell hockey like a champ and is already famous as being the littlest Big Red fan in Lynah rink.


1. Bauman DE. Bovine somatotropin: review of an emerging animal technology. Journal of dairy science. 1992;75(12):3432-51.

2. Bauman DE. Bovine somatotropin and lactation: from basic science to commercial application. Domestic Animal Endocrinology. 1999;17(2-3):101-116.

3. Capper JL, Castaneda-Gutierrez E, Cady RA, Bauman DE. The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production. Proc.Natl.Acad.Sci.U.S.A. 2008;105(28):9668-9673.

4. Medicine C for V. CVM Updates – FDA Responds to Citizen Petition on BST. Available at: Accessed February 29, 2012.

5. Medicine C for V. FDA Veterinarian Newsletter – FDA RESPONDS TO CITIZEN PETITION ON BST. Available at: Accessed February 29, 2012.

6. Anon. NIH Technology Assessment Conference Statement on Bovine Somatotropin . JAMA: The Journal of the American Medical Association. 1991;265 (11 ):1423-1425.

7. Daughaday WH, Barbano DM. Bovine Somatotropin Supplementation of Dairy Cows: Is the Milk Safe? JAMA: The Journal of the American Medical Association. 1990;264(8):1003-1005.

8. Michael Hansen, Ph.D., Jean M. Halloran, Edward Groth III, Ph.D. LYL. Potential Public Health Impacts Of The Use Of Recombinant Bovine Somatotropin In Dairy Production-Part 1. Consumers Union. 1997. Available at: Accessed March 1, 2012.

9. Torkelson, A.R., Lanza, G.M., Birmingham, B.K., Vicini, J.L., White, T.C., Dyer, S.E., Madsen, K.S., and Collier RJ. Concentrations of insulin-like growth factor 1 (IGF-1) in bovine milk: Effect of herd, stage of lactations, and sometribove. Journal of Dairy Science. 1988;71(Supplement 1):169.

10. Collier RJ, Miller MA, Hildebrandt JR, et al. Factors affecting insulin-like growth factor-I concentration in bovine milk. Journal of dairy science. 1991;74(9):2905-11.

11. Judge LJ, Erskine RJ, Bartlett PC. Recombinant Bovine Somatotropin and Clinical Mastitis: Incidence, Discarded Milk Following Therapy, and Culling. Journal of Dairy Science. 1997;80(12):3212-3218.

12. Collier RJ, Byatt JC, Denham SC, et al. Effects of sustained release bovine somatotropin (sometribove) on animal health in commercial dairy herds. Journal of dairy science. 2001;84(5):1098-108.

  1. Becky Albaugh #

    I am so thankful for these blogs. I have worried about this . I love how that was written too, with the bold type to get right to the point. Super!
    Alice ,I am thrilled with all of your topics as well as your friends’ input and expertise. You always seem to address something we are going through or worrying about. Even experienced Grammy’s are facing some different issues today.
    Keep them coming!
    I wish we had communication like this back in the day. .


    March 19, 2012
    • I totally agree…we had nothing like this when our kids were little…this is always incredible to me on a daily basis.


      March 20, 2012
  2. andra #

    Sounds like she works for the dairy industry. I don’t buy it and I don’t trust the FDA.
    Which studies prove humans are not affected?
    At the most basic, why do you want to feed yourself or anyone else for that matter milk that is designed it’s very core to grow a 2000 pound mammal.
    You can get calcium and protein many other ways.

    Liked by 1 person

    March 19, 2012
    • Well, if you’ve decided on an opinion and are unwilling to consider actual scientific evidence that runs contrary to that opinion, then this post is clearly not for you. It’s meant for those of us who haven’t the time or inclination to do the required web searching to come up with the data ourselves, and appreciate having an expert to digest it for us. You noticed the 12 references she provided for her conclusions, right? Was it really necessary to insult the writer?

      As a biologist, I can tell you for certain she’s right about the “protein hormones get broken into their component amino acids in the stomach/intestines” part. If you don’t believe that, ask a diabetic about their insulin pills….

      At any rate, your assertion about cow’s milk being “designed” to grow a cow isn’t entirely accurate. Humans and modern cows have co-evolved, with humans breeding cows for use as sources of food. Modern dairy cow’s milk has been “designed” by humans for human use, through millennia of selective breeding. Why NOT drink cow’s milk, if you’ve evolved (as those of Northern European descent have) to be able to use it as a nutritious calorie source? As with most foods, it’s only harmful if you overdo it. (Naturally, if you’re lactose-intolerant or allergic, that’s a whole different deal.)


      March 19, 2012
    • dairygirl07 #

      Rbst was actually developed by researchers trying to find a way to help those affected by dwarfism by stimulating their bodies to grow taller by supplementation of bovine somatotropin. It didn’t work, i.e. had no effect on people, due to it being species specific. What they did find however, was that it made a dairy cow produce milk more efficiently. That is why people don’t have to worry about so called negative effects. Because there are no effects in humans.


      March 3, 2014
  3. I appreciate the research and it is very much reassuring to know that in a pinch I don’t have to worry about rBST. But I will still chose to buy my organic rBST free milk….or soy milk.

    Liked by 1 person

    March 19, 2012
  4. Donkey #

    Thankfully I am from Canada and would like to point to the fact that the bGH has not been allowed in Canada and many other countries where -should I mention it- Monsanto has been trying to sell it. The author might be referring to researches but it would be appropriate to look into who funded those studies as Monsanto has been known to finance studies and manipulate the results to clear its products from any ill effects (even university ones, yes!).

    Other researches have shown opposite results as far as herd health goes and a lot of farmers have stopped using it despite the economical avantage because it was crippling their herds. There is also a labelling issue where activists were unable to force the identification (labelling) of brGH milk because they were told that pointing it out would make it appear as though it was bad. So instead you can find milk labelled brGH free.

    Personnally I would not want to drink milk (or feed it to my baby!) from cows having received the bGH because of the increased presence of mastitis infections and antibiotics use in cows having received it. I unfortunately think this article is very biased and does not give a good idea of the whole picture. I would therefore highly recommend to anybody truly interested in this matter to further look into it. Having researched it a lot myself I have come to a different conclusion than the one presented in this article.

    Liked by 2 people

    March 19, 2012
    • I know this is a controversial topic, and I appreciate your comment. I did want to clear up one thing: All milk that is sold commercially is tested for antibiotics. Whether you buy organic or conventional milk (from cows treated with rbST or not), your milk is clear of antibiotics. Farmers who use antibiotics to treat mastitis dump that milk until it is clear of antibiotics.

      You are welcome to submit a rebuttal article, as long as it is backed by science.


      March 19, 2012
      • Judi Miller #

        “Health Canada, January 1999 – Given the apparently anomalous result seen at 14 weeks in the 0.1 mg/kg/day group (one out of 30 rats showed an antibody response), the panel feels that the possibility of hypersensitivity reactions deserves further exploration. The sponsor suggested that this finding was either due to a labelling error or to extreme hypersensitivity in the responding rat. The panel is concerned by the continuing uncertainty of explanation and by the sponsor’s inability to resolve the question of a labelling error that implies a breach of good laboratory practice. The panel is less concerned about antibody responses to rbST at extremely high doses, but feels that there is a need for clarification of hypersensitivity risk from orally administered rbST at lower dosages. It is the opinion of the panel that the sponsor should repeat the 90-day study of orally administered rbST at doses of 0.1, 0.5 and 5 mg/kg/day. In order to reconcile the antigenicity controversy with Health Canada officials, the sponsor should submit data obtained from studies conducted in accordance with good laboratory practice and analysed to the satisfaction of Health Canada scientists.”

        Liked by 1 person

        September 15, 2014
      • The author works at Cornell. The one school where it seems all of these studies miraculously show zero harm to humans. This is the same school in which one professor essentially called everyone who doesn’t trust GMOs an ignorant, anti-science rube.

        Thanks, but I think I’ll find a less biased source of information.


        September 18, 2014
    • Becca #

      Monsanto doesn’t own rbST anymore. Alltech sells it now and has for a while. All companies (drug, nutritional supplements, etc) financially support research at private and Land Grant institutions and it is up to the researchers to publish the results. If private citizens would like to support research, I am sure no one would turn down your money. Where is this evidence of herd health statistics? Mastitis has been shown to increase with milk production independent of rbST use. Maybe that’s what you are referring too? There are so many factors that go into the health of a cow. It is presumptuous to blame one factor.


      March 20, 2012
      • Also, as a university researcher who has worked on projects with corporate funding on occasion – this has NEVER caused me to “slant” my work towards what I perceive to be the company’s interests, nor to publish data that aren’t as accurate as I can make them. I know of no scientists (personally; I’m sure the rare exception, as always, exists) who would put funding ahead of the science. The fact that a company funds research doesn’t automatically make that research suspect (and the company isn’t funding the peer reviewers who determine whether the data are published).


        March 21, 2012
      • Actually Alltech makes a yeast product and an algae product and has nothing to do with Posilac (rBST brand name).

        Elanco Animal Health owns Posilac.


        March 2, 2014
      • Judi Miller #


        Incidence rate of clinical mastitis = 45 cases / 100 lactations
        Estimate based on the three major studies which provided data on clinical mastitis incidence rates (5407, 5422, 20). In the control cows in these studies, there were 441 cases in 975 lactations = 45 cases / 100 lactations.
        Health Canada, November 1998

        “Proportion of cases during treatment period = 78%
        Of the 441 cases reported above, 345 (78%) occurred during the treatment period.

        rbST increases risk of clinical mastitis by 25%
        In Section 7.1.2 of this report the estimate of the increased risk of clinical mastitis associated with rbST use was 25% – 30%. 25% represents a slightly conservative estimate.

        77% of milk production occurs after day 60
        This estimate is based on a standard lactation curve with peak production of 39Kg/day and a persistency value of 0.133

        rbST increases milk production by 10%
        In section 4.1.2 the increase in FCM was estimated to be 11.4% in primiparous cows and 15.6% in multiparous cows. However, it was noted that these results were obtained in institutional herds under very intensive nutritional management. Consequently, a more conservative estimate of 10% has been selected.

        100 cow dairy herd producing, on average, 8000 l per lactation
        This is just a hypothetical herd for the purpose of the following calculations”


        September 16, 2014
  5. Luciana #

    I love the article! Thanks!!! (You can’t desagree with science but you can choose for other reason not to drink rbST milk or any other kind of milk…). I have a question: does this apply with chicken and eggs? 
    I try to eat organic products (because I am afraid and whant the best for me and my family), but I also think that “organic” lable is been used as marketing, missinforming us and scaring us, for us to buy more organic, (which is more expensive!!!).  Thanks for this and all the other articles!!! I love your blog!!!


    March 19, 2012
    • Thank you Luciana! I don’t have a good answer to your question about chicken and eggs. It would be a good topic for a future article. I’m like you – I err on the side of caution (especially now that I’m a mom), even though I know I don’t know the full story and probably overpay at times. That’s why I appreciate knowing more of the science behind rbST.


      March 19, 2012
  6. Thanks, Alice. Great post! I think a lot of people think that rBST is something that only large corporate farms use but really, rBST used to help a lot of small dairy farmers too who perhaps didn’t have the means nor the desire to expand the size of their farm and take on all the added costs (economically, physically and psychologically) that go along with it. Unfortunately, a lot of co-ops (organizations made up of dairy farm members formed to market their milk) have forced their members to pledge not to use it so that they can have that label on their buyers’ end product. You can’t deny the science, but how do you address the emotions that get stirred up with this topic?

    And about the Canadian system, they have a quota system whereby each farm contracts to provide a certain amount of milk. Producing any more would not make sense because the price for “over-quota” milk is low. Thus rBST wouldn’t really make sense to use there anyway so why would they? Monsanto does not own the rights to it anymore anyway and haven’t in a few years now.


    March 20, 2012
    • Donkey #

      The quota is not the reason why it is not used in Canada. Its use was never deemed safe by our “FDA” (our equivalent). But even then, the quota would not limit its use anyways because if you can produce the same amount of milk with less cows, you’re still ahead right? Monsanto might not own the rights to it anymore but they are the ones who put it on the market and knowing Monsanto’s history of devious and dishonnest practices for getting agricultural products approved, its safety is, in my opinion far from guaranteed. Besides, if it was so good why is it that NO other countries approved it?

      “The 1998 reviews by Health Canada determined the use of rBGH increases the risk of mastitis by 25 percent, affects reproductive functions, increases the risk of clinical lameness by 50 percent, and shortens the lives of cows (Report of the Canadian Veterinary Medical Association Expert Panel on rBST,’ Prepared for Health Canada, November 1998.). Nonetheless, Monsanto lobbied the Canadian government hard to win rBGH approval. Dr. Margaret Hayden, a Health Canada researcher, reported to the Canadian Senate that officials from Monsanto had offered between $1 million to $2 million to Health Canada scientists’an offer she says could only be understood as an attempted bribe (Baxter, James, ‘Monsanto Accused of Attempt to Bribe Health Canada for rBGH (Posalic(R)) Approval.’ The Ottawa Citizen, October 23, 1998).”

      “Also, Margaret Miller was a former supervisor for Monsanto and was actively involved in the GBH program. In fact, she was the very person who created the report that was sent to the FDA seeking approval to use GBH in the milk industry. Soon after she finished the report, she left her job at Monsanto and went to work for the FDA as the new Deputy Director of Human Food Safety. Ironically, her first assignment with the FDA was to approve her own report (Posted 16 Nov 2010 in Finance and Politics of cancer research and treatment, Fraud, Legal
      by James Street)”.

      Liked by 1 person

      March 20, 2012
  7. As an aggie, I appreciate the article and agree with you. However FDA studies will not sway the hardcore anti-everything crowd, even if the science is spot on and bureaucracy free.


    March 20, 2012
  8. Jared #

    There are many well run dairies that use and don’t use rBST. The incidents of mastitis and lameness on any of these farms is environment/management related, not if they use rBST. We have used it on our famr, but were forced to stop by our co-op. I would use it again if permitted, and would not be afraid to allow my family to consume that milk. The rBST free label was a marketing ploy for processors to gain extra $$ from consumers and not return much of it to the farmers. Organic is much the same, and I would never drink milk from an organic farm.


    March 20, 2012
    • I’ve heard that organic milk tends to have higher bacteria counts prior to pasteurization due to the complete disallowal of antibiotics (don’t cows have to be permanently removed from organic track if they receive antibiotics?). Is there any truth to this? Also, is it true that there is a holding period for “non organic” milk from cows that are being treated with antibiotics, I.e. their milk has to be dumped and can’t be sold for a specific period of time , meaning there really isnt much of a risk that “non organic” milk contains antibiotics? Thanks.


      March 20, 2012
      • Nathan #

        Angela, as the author posted above, all milk is tested for antibiotics at the processing plant so no milk sold (organic or not) contains antibiotics. There is a withdrawal time for most drugs for all milk, organic or not. You dump the milk for that long, then you send a sample to a lab to be tested to be certain the cow is clear of the drug before you put her back in the tank for sale. That milk is often used to feed baby calves.

        The bacteria counts prior to pasteurization have more to do with how the cows are cleaned/prepped prior to milking and the cleanliness of their housing than
        anything else.

        I agree with the people who say that organic is mostly a ploy by the food companies to make more money. It especially annoys me when milk is labeled ass antibiotic free since all milk is antibiotic free and its just duping people into paying more for the same quality. Also all milk contains some hormones, so if you ever see anything labeled as such, don’t believe it.

        We’ve never used it, so I can’t really say much about how it affects mastitis or reproductions and the like, but I do know that on big dairies, cows that don’t produce as well as others don’t last long either, so using BST may actually lengthen some cows lives. . .


        March 21, 2012
  9. Several milk purchasers and resellers have elected not to purchase milk produced with rBST. The nation’s largest dairy processor, Dean Foods, no longer sells milk from rBST-treated cows though an email from Dean Foods received by a consumer on September 23, 2010, states, “At Dean Foods, we believe that our dairy producers have the right to produce safe, high-quality milk using any approved and available technology…” which would include Artificial Growth Hormones or rBST/rBGH. The top 3 grocery retailers in the nation, Wal-Mart, Kroger, and Costco have pledged not to sell such milk in their stores.


    March 21, 2012
  10. Jen Larsen #

    “When ingested by mouth, it is digested and broken into constituent amino acids in your GI tract, just like every other protein eaten, and therefore results in zero impact as a growth hormone…”

    Hi Katie and Alice,

    I have a question about the statement I quoted above. We know that intact proteins are absorbed and can be detected in the blood of humans, rodents, etc. when ingested. This appears to be a very important process for development of cellular and humoral immune response and establishing oral tolerance to ‘foreign’ food protein. We’ve known this for a long time (see work from Walker and Isselbacher in early 70s, etc).

    If this isn’t really true for rBST (was this studied and published or just assumed??), why is this so? Peptide length? Composition of milk? Other factor?

    Thanks in advance-


    April 30, 2012
    • Katie #

      Hi Jen – Thanks for your question and the opportunity to clarify. (And I apologize for my delay in getting you a reply; seems there just aren’t enough hours in the day with a 4 month old!).

      According to the research I’ve seen, there are several pieces of evidence that suggest that bST would be digested and not have a biological effect (in addition to bST not being recognized by human receptors). First, as amino acid chain length increases, the likelihood that the peptide could pass across the intestinal decreases – and at 191 amino acids, ST is longer than others that have been studied, including insulin at 51 amino acids. Second, they fed rats bST and found that “neither bSt nor growth-promoting fragments of bST are absorbed after oral administration” (“The lack of a growth-promoting effect of orally administered bovine somatotropin in the rat body-weight-gain bioassay” William J. Seaman et al. Fundamental and Applied Toxicology
      Volume 10, Issue 2, February 1988, Pages 287–294). Hope that helps clarify that bST would be included in proteins that would be digested and not be absorbed across the intestinal wall.


      May 4, 2012
      • Jen Larsen #

        Thanks Katie. And no worries on the delay- your post was published weeks before my question!

        Anyway, I also couldnt find any data in people with regard to rBST absorption, but certainly there is a lot of investigation in people to support the absorption of larger proteins (ovalbumin at 385 residues and BSA at almost 600), due to the commonality of these allergies in people.

        So it doesnt appear to be primarily the peptide size that determines the absorption (unless varying methodology is impacting the different results for rBST). Anyway, I’m asking not because I’m concerned about biological activity of rBST in people but more to investigate whether certain proteins can be more allergenic than others, and why. This appears to be the case in people with certain antigens (peanut, for example), and the antigenicity is altered by heat treatment. This is very interesting and we dont know anything about this in companion animals which is my area.

        Thanks again!


        May 7, 2012
  11. Jla #

    All I know is that if I consume any product from cows treated with rbst I break out in a violent case of hives. Once discovered I put this to the test repeatedly to make sure that this was the cause of my hives. After extensive time and pain invested in personal agony the evidence was conclusive that all products which were produced from cows treated with rbst produced a reaction. I would then would wait out the time till y hives would disapear the would consume products not treated with rbst and there was no reaction. Maybe I am 1 in a million but if not I hope this els anyone else who may be suffering and not know why.

    Liked by 1 person

    December 18, 2012
  12. Rana #

    Very biased and false article!…. I am doing research on rbst, and there are MANY things wrong with it!
    To cows: FDA Posilac® Package Insert
    Although the FDA allowed rBGH to be commercialized, it acknowledged that it increased the rates of 16 harmful physical effects on cows and required an insert, listing the following conditions, be placed in every package sold. These include:
     Reproductive Effects: Reduced pregnancy rates, increase in days open, increased incidence of retained placenta, decreased gestation length and birth weight of calves
     Increased rate of clinical mastitis and Increased rate of subclinical mastitis (somatic cell count)
     Increased body temperature unrelated to illness (heat stress)
     Increase in digestive disorders, such as indigestion, bloat and diarrhea
     Increase in reduced feed intake (off-feed)
     Increased numbers of enlarged hocks and lesions and increased numbers of foot disorders
     Increased number of injection site reactions – swelling
     Reductions in hemoglobin and hematocrit values

    Cows injected with the biotech hormone show heavy localization of IGF-1 in breast (udder) epithelial cells; this does not occur in untreated cows.
    IGF-1 induces rapid division and multiplication of normal human breast epithelial cells in tissue cultures.
    It is highly likely that IGF-1 promotes transformation of normal breast epithelium to breast cancer.
    IGF-1 maintains the malignancy of human breast-cancer cells, including their invasiveness and ability to spread to distant organs.
    The breast tissues of female fetuses and infants are sensitive to hormonal influences. Imprinting by IGF-1 may increase future breast-cancer risks and sensitivity of the breast to subsequent unrelated risks such as mammography and the carcinogenic and estrogen-like effects of pesticide residues in food, particularly in premenopausal women.

    Experiments have further shown that IGF-1 enhances the growth of cancerous breast cells in mice. The new studies linking higher rates of cancer with higher rates of IGF-1 in cancer patients

    Increased cancer risk: When rBGH is injected into a cow, it elevates levels of another powerful growth hormone, IGF-1, which is present in both cows and humans. IGF-1 is a necessary hormone, but in excessive amounts, it has been linked in hundreds of studies to an increase in breast, prostate, colon, lung and other cancers in humans. Numerous scientific data suggest IGF-1 in milk survives human digestion and enters the bloodstream in sufficient quantities to potentially trigger increased cancer rates.

    Antibiotic resistance: Cows given rBGH experience statistically higher rates of mastitis, a painful udder infection. It is treated with antibiotics such as penicillin, amoxicillin and erythromycin, which are also used to treat infections in people. Bacteria resistant to these antibiotics end up in the milk, air, soil and water, resulting in increased antibiotic resistance in humans, a major health problem.

    Liked by 1 person

    December 22, 2012
  13. Anna #

    Rana thank you for the post. Once read, “We are all pigeon hole scientists and we need to be reminded of that.” I think the controversy within the FDA and also with the Canadian researchers on the initial review should say enough on this issue.


    January 10, 2013
  14. Hi Katie and ScienceofMom,
    Overall, this is a good, thoughtful article, and the science agrees with many of the things I have read. The one point that doesn’t is Katie’s paragraph about animal welfare. The article she cites (12) states that rbST is safe for use, but does say that “cows supplemented with bST used more medications for health events other than mastitis,” and “This usage was associated primarily with treatments for disorders of the foot and hock. Supplemented cows had a slight increase in foot disorders.” Animal welfare is the reason that Canada and the EU has banned the use of rbST, although the studies that influenced these decisions were earlier than the one Katie cites.

    So thank you for clearing up the human safety myths surrounding rsBT, but readers concerned about animal welfare may need more information that what was provided.


    February 22, 2013
  15. Anonymous #

    Connections of Cornell University to Monsanto. Article discussing how Cornell and Monsanto are promoting the benefits of rBGH.


    March 10, 2013
  16. Nicole #

    I belive this article was very helpful and full of great information. Currently, I am writing a research paper that is gathering information about the rBST hormone and its effect on the human body. I am looking at both arguements and plan to promote both sides of the story, for as it was stated above, the opinion is up to each individual parent and consumer. Thanks again Science of Mom! I belive their need to be more blogs that are credible and back their information like this one!! 🙂


    April 3, 2013
  17. John Edwards #

    I am questioning the lack on concrete studies on this sited, and especially would like to question the premise that the hormones are broken down by the stomach. We should all be aware of “Hamburger Thyrotoxicosis” where thyroid is broken down with hamburger, cooked, and then caused hyperthyroidism humans who eat this beef. I know this is a different type of hormone, I do not take this article seriously, and would much rather a conclusive study done. Especially in light of the FDA’s connections to big agriculture as of late, we must focus on the science of claims more than statements and surveys.

    Liked by 1 person

    August 8, 2013
  18. This blog post is quite disturbing. Especially because it focuses on children’s risks associated with rbST. The author clearly sates that:

    “Lastly, I will touch on the effects on the health and wellbeing of the cows only briefly as ultimately this may be a social issue (vs. a health issue related to our children). Use of rbST on farms does not lead to increased incidences of health problems in dairy cattle.”

    And yet the National Institute of Health, in a meta study, found the following:

    “Recombinant bovine somatotropin was found to increase the risk of clinical mastitis by approximately 25% during the treatment period but there was insufficient data to draw firm conclusions about the effects of the drug on the prevalence of subclinical intra-mammary infections. Use of rBST increased the risk of a cow failing to conceive by approximately 40%. For cows which did conceive, there was no effect on services per conception and only a small increase in average days open (5 days). Use of the drug had no effect on gestation length, but the information about a possible effect on the risk of twinning was equivocal. Cows treated with rBST had an estimated 55% increase in the risk of developing clinical signs of lameness. Few studies reported data on culling, but based on those that did, there appeared to be an increase risk of culling evident in multiparous cows.”.

    I don’t know, seems massively contradictory to me.


    February 4, 2014
    • As I understand it, any cows that have very high milk production (whether because they are naturally high milk producers or because they have been supplemented with rBST) will have higher incidence of mastitis and/or lameness. It’s just that their bodies are working so hard to produce that much milk. I haven’t seen evidence that the increase in mastitis and lameness is actually due to rBST specifically once you control for the higher milk production.

      Liked by 1 person

      February 28, 2014
  19. Jordan #

    I am a fifth generation dairy farm girl, and I really appreciate this article! Many people ask me questions when they find out I have dairy cows, and one of their main concerns is the use of rbST in our animals. Many people that are against it are simply misinformed. I agree that, even when given injections, there is no residue in milk. The rbST is used up by the cow, just like any natural hormone she would have produced. Milk is also tested many times- almost more than you would believe! At the farm and multiple times at the bottling/product plants, and if it doesn’t meet standards, it is all disposed of. I know that it is easy to gain false information in today’s world, and I thank you for helping set the record straight! Honestly, and from my own life experiences, farmers care exceptionally well for their animals- mine are like my pets!- and the people they are producing for. If you get the chance, please thank a farmer for working hard every day of the year to put food on the world’s tables!
    Any questions or concerns, never be afraid to ask! 🙂


    June 19, 2014
  20. Get your calcium from vegtables, eat meat nd drink one beer per day. Also drink Birch tree Chaga.


    September 12, 2014

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