Reprinted from The Ecologist, Vol 28, No 5, Sept/Oct 1998

Bovine Growth Hormones

by Paul Kingsnorth
The classic Monsanto combination of bad science, misleading claims, the silencing and rubbishing of opponents and the hushing-up of damning information, is abundantly evident in the case of the corporation's first commercially-available genetically-modified product: bovine growth hormone, or Bovine Somatotropin as it is known in the US.

Recombinant Bovine Growth Hormone (rBGH - also known as Bovine Somatotropin, or BST) is a genetically engineered copy of a naturally-occurring hormone produced by cows. The purpose of rBGH is to enable cows to produce more milk than they naturally would. It works by altering gene expression of glucose transporters in the cow's mammary gland, skeletal muscle and omental fat. The gene facilitates the repartitioning of glucose to the mammary gland, which in turn produces more milk.

Cows injected with a daily dose of Monsanto's rBGH - marketed under the brand name Posilac - are generally expected to increase their milk yield by between 10 and 20 per cent. However, the problems and side-effects associated with rBGH are legion. Such are its actual and potential dangers that it is banned in Canada, the European Union and a number of other countries, despite the best efforts of Monsanto to prise open those markets. However, rBGH has been in use in other countries - most notably the USA - for some years. And it is from there that the bad news has been emerging.

Who Benefits?
The US Food and Drug Administration (FDA) declared rBGH officially "safe" in 1993, and Monsanto began selling Posilac to dairy farmers in February of the next year.(1) In the USA there are two obvious benefits of its widespread use: an estimated annual income for Monsanto of between $300 and $500 million, and an estimated 12 per cent increase in the nation's supply of milk.(2) Yet since the l950s, America's dairies have consistently produced more milk than the nation can consume, the surplus being bought up every year by the Federal Government to prevent the price from plummeting. In the period 1980-85, the US government spent an average of $2.1 billion every year buying surplus milk.(3) No-one in the US needs the extra milk that Posilac can provide.

What's more, the animals treated with the hormone are subjected to tremendous stress as a result. Normally, for about 12 weeks after a cow calves, she produces milk at the expense of her health. The cow loses weight, is infertile and is more susceptible to diseases. Eventually, milk output diminishes and the cow's body begins to recover. By injecting rBGH, a farmer can postpone that recovery for another eight to 12 weeks, substantially increasing the cow's milk output, but also rendering her more susceptible to disease.(4)

For a comprehensive list of the potential ill-effects of rBGH on cows, one need look no further than the warning label which the US Food and Drugs Administration (FDA) requires Monsanto to include in every shipment of Posilac. The label outlines 21 health problems associated with the use of Posilac, including cystic ovaries, uterine disorders, decrease in gestation length and birth weight of calves, increased twinning rates and retained placenta.(5)

Potentially the most serious problem, however, is the increased risk of mastitis, or inflammation of the udder. A cow with mastitis produces milk with pus in it. Dairies will not accept milk which has an abnormally high somatic cell count (i.e., a high proportion of pus), and mastitis can thus be a serious source of lost revenue to the dairy farmer. Many farmers seek to treat the problem with antibiotics, but antibiotic residues in milk are suspected of causing health problems in humans who drink it, as well as contributing to the development of antibiotic resistance amongst bacteria.(6)

Concerned by the potential effects of rBGH, the US National Farmers Union (NFU) set up an rBGH telephone hotline in 1994, for farmers to report any problems associated with Posilac. Hundreds of farmers called the hotline. John Shumway, a New York State dairy farmer, told the hotline that he had had to replace 50 cows as a result of adverse reactions to Posilac. His estimated losses from the use of rBGH came to about $100,000.(7) Melvin Van Heel, a Minnesota farmer, experienced mastitis, abortions and open sores in his rBGH-treated cows. "I got more milk, but I didn't think it was worth it," he said. Michigan farmer Steve Schulte reported that his vet's bill fell dramatically after he stopped using rBGH. Florida Farmer Al Cole lost eight cows and had to cull an additional 15. Three others later gave birth to deformed calves.(8)

The NFU has a record of many more such complaints. Such is the dissatisfaction, that farmers all over the States are giving up using the hormone. In 1995, the NFU reported that "in some areas of the country, farmers are reporting that 60 to 90 per cent or more of the farms that have tried BGH have discontinued its use."(9)

It should thus be quite clear that it is only Monsanto that benefits from the sale of this perfectly useless product.

The Human Health Risks
Even leaving aside the health problems caused by antibiotic residues in milk - a side-effect of an increase in mastitis - the effects of rBGH on human health could be devastating. Most worrying are scientific studies linking rBGH to cancer.

When a cow is injected with rBGH, its presence in the blood stimulates production of another hormone, called Insulin-Like Growth Factor 1 (IGF-1), a naturally-occurring hormone-protein in both cows and humans. The use of rBGH increases the levels of IGF-1 in the cow's milk. Because IGF-1 is active in humans - causing cells to divide - some scientists believe that ingesting high levels of it in rBGH-treated milk could lead to uncontrolled cell division and growth in humans - in other words, cancer.(10)

Monsanto have naturally been keen to deny that IGF-1 levels in rBGH treated milk could be high enough to pose a threat. Writing in The Lancet in 1994, the company's researchers claimed that "there is no evidence that hormonal content of milk from rBST treated cows is in any way different from cows not so treated."(11) Yet in a later issue of the same journal, a British researcher pointed out that Monsanto had admitted, in 1993, that "the IGF-1 level [in milk] went up substantially [about five times as much.]" when rBGH was used.(12)

A number of studies have since warned of the effects of excess IGF-1. Two British researchers reported in 1994 that IGF-1 induced cell division in human cells.(13) The next year, a separate study discovered that IGF-1 promoted the growth of cancer tumours in laboratory animals, by preventing natural cell death.(14)

In 1996, Professor Samuel Epstein, from the University of Illinois, Chicago, conducted a detailed study of the potential effects of increased levels of IGF-1 on humans. Epstein's resulting, peer-reviewed, paper found that IGF-1 from rBGH treated cows may lead to breast and colon cancer in human milk-drinkers. Epstein's fiery conclusion was that "with the complicity of the FDA, the entire nation is currently being subjected to an experiment involving large-scale adulteration of an age-old dietary staple by a poorly characterized and unlabelled biotechnology product... it poses major potential health risks for the entire US population."(15)

Two studies published earlier this year seem to back Professor Epstein's findings. A study of American women published in The Lancet in May found a seven-fold increased risk of breast cancer among pre-menopausal women with high levels of IGF-1 in their blood.(16) A separate study published in Science in January found a four-fold increase in risk of prostate cancer among men with high levels of IGF-1 in their blood.(17) [See boxes 1 and 2]

Hormone Economics
Quite apart from the health risks associated with rBGH, its increased use across the world would contribute to the decline of the small farm and the monopolization of agriculture by multinational corporations. Basic economics tells us that an increase in the supply of a product leads to a fall in its price. The US government has only avoided an overall crash in milk prices in recent decades by buying up surplus milk. If widespread use of rBGH in any country leads to a significant increase in milk supply, and if the government is unable or unwilling to buy up any surplus, the resulting dramatic fall in prices will drive small farmers to the wall and ensure, as many other aspects of the 'Green revolution' have done, that big, intensive, high-technology farms are the ones that survive in an increasingly competitive marketplace.

Gagging the Critics
Monsanto's response to those who dare to criticize rBGH has been the usual intimidation, lawsuits, manipulation of facts and expensive propaganda. In this they have been aided and abetted, in the US, by the FDA, which has been referred to by critics as 'Monsanto's Washington Office' [see Ferrara in this issue].
(continues after box)

Bovine Growth Hormone and Prostate Cancer
As reported in a January 23, 1998 article in Science, men with high blood-levels of the naturally occurring hormone, insulin-like growth factor 1(IGF-1), are over four times more likely to develop fullblown prostate cancer than are men with lower levels. The report emphasized that high IGF-1 bloodlevels are the strongest known risk factor for prostate cancer, even exceeding that for a family history of the disease, and that reducing IGF-1 levels is likely to prevent this cancer. It was further noted that IGF-1 markedly stimulates the division and proliferation of normal and cancerous prostate cells and that it blocks the programmed self-destruction of cancer cells, thus enhancing the growth and invasiveness of latent prostate cancer. These findings are highly relevant to any efforts to prevent prostate cancer, whose rates have escalated by 180 per cent since 1950, and which is now the commonest cancer in non-smoking men, with an estimated 185,000 new cases and 39,000 deaths in 1990.

While warning that increasing IGF-1 blood-levels, due to treating the elderly with growth hormone (GH) to slow ageing, may increase risks of prostate cancer, the 1998 report appears unaware of the fact that the entire US population is now exposed to high levels of IGF-1 in dairy products. In February 1995 the Food and Drug Administration (FDA) approved the sale of unlabelled milk from cows injected with Monsanto's genetically engineered bovine growth hormone, rBGH, to increase milk production. As detailed in a January 1996 report in the International Journal of Health Services, rBGH milk differs from natural milk chemically, nutritionally, pharmacologically and immunologically, besides being contaminated with pus and antibiotics resulting from mastitis induced by the biotech hormone. Most critically, rBGH milk is supercharged with high levels of abnormally potent IGF-1, up to ten times the levels in natural milk and over ten times more potent. IGF-1 resists pasteurization and digestion by stomach enzymes and is well absorbed across the intestinal wall. Still-unpublished Monsanto tests, disclosed by the FDA in summary form in 1990, showed that statistically significant growth-stimulating effects were induced in organs of adult rats by feeding IGF-1 at the lowest dose levels for only two weeks. Drinking rBGH milk would thus be expected to increase blood IGF-1 levels and to increase risks of developing prostate cancer and promoting its invasiveness. Apart from prostate cancer, multiple lines of evidence have also incriminated the role of IGF-1 as risk factors for breast, colon and childhood cancers.

Faced with such evidence, the FDA should immediately withdraw its approval of rBGH milk, the sale of which benefits only Monsanto while posing major public health risks for the entire US population. Failing early FDA action, consumers should demand explicit labelling and only buy rBGH-free milk.

Prepared by The Cancer Prevention Coalition.
Contact: Samuel S. Epstein, MD, Professor of Environmental Medicine at the University of Illinois School of Public Health, Chicago, and Chairman of the Cancer Prevention Coalition.

The first response by the Monsanto/FDA axis to concerns about rBGH in milk (US surveys have consistently shown that more than 70 per cent of respondents do not want to drink it) was to turn to the law. In 1994, the FDA warned retailers not to label milk that was free of rBGH thus effectively removing from consumers the right to choose what they drank. The FDA's main justification for this was that, in their words, there was "virtually" no difference between rBGH-treated milk and ordinary milk. Labelling would thus unfairly discriminate against companies like Monsanto.(18)

Piccy of Doctor
"I'm going to put you on a course of hormones - I recommend drinking three pints of milk a day"
The FDA official responsible for developing this labelling policy was one Michael R. Taylor. Before moving to the FDA, he was a partner in the law firm that represented Monsanto as it applied for FDA approval for Posilac. He has since moved back to work for Monsanto.(19)

As a result of this policy, the FDA threatened retailers with legal action if they dared to label their milk 'BGH-free'. Monsanto itself filed two lawsuits against milk processors who labelled their milk, and posted warnings to others not to do so.(20) The American ice-cream makers Ben and Jerry, who have always refused to use BGH-treated milk, recently filed a lawsuit against the state of Illinois, which ruled that they cannot label their products 'BGH-free'.(21)

Monsanto and its allies have even used the US Constitution to prevent consumers knowing what is in the milk they drink. In April 1994, the State of Vermont passed a law requiring that products containing rBGH be clearly labelled. A coalition of dairy industries and Monsanto immediately filed a suit asserting that the new law was "unconstitutional", on the grounds that it violated the First Amendment, which asserts a constitutional fight not to be forced to disclose information. Monsanto won.(22)

Faced with growing consumer outrage at these tactics, Monsanto has now reluctantly abandoned its lawsuits against retailers, and labelling milk 'BGH-free' is now permitted in the US. But the FDA still refuses to require producers to so label their milk, and even now, many people have no idea what's really in their milk.
(continues after box)

Bovine Growth Hormone and Breast Cancer
As reported in a May 9 article in The Lancet, women with a relatively small increase in blood-levels of the naturally occurring growth hormone, Insulin-like Growth Factor 1 (IGF-1), are up to seven times more likely to develop premenopausal breast cancer than women with lower levels. Based on those results, the report concluded that the risks of elevated IGF-1 blood-levels are among the leading known risk factors for breast cancer, and are exceeded only by a strong family history of the disease or unusual mammographic abnormalities. Apart from breast cancer, an accompanying editorial warned that elevated IGF-1 levels are also associated with greater-than-any-known risk factors for other major cancers, particularly colon and prostate.

This latest evidence is not unexpected. Higher rates of breast, besides colon, cancer have been reported in patients with gigantism (acromegaly) who have high IGF-1 blood-levels. Other studies have also shown that administration of IGF-1 to elderly female primates causes marked breast enlargement and proliferation of breast tissue, that IGF-1 is a potent stimulator of human breast cells in tissue culture, that it blocks the programmed self-destruction of breast cancer cells, and enhances their growth and invasiveness.

Again, these various reports appear surprisingly unaware of the fact that the entire US population is now exposed to high levels of IGF-1 in dairy products.

For these reasons too, the FDA should withdraw its approval of rBGH milk. A Congressional investigation of the FDA's abdication of responsibility is well overdue.

Prepared by The Cancer Prevention Coalition.
Contact: Samuel S. Epstein, MD, Professor of Environmental Medicine at the University of Illinois School of Public Health, Chicago, and Chairman of the Cancer Prevention Coalition.


In other areas of society, Monsanto has also been accused of underhand methods as it tries to cover up the truth about rBGH. The now-notorious 'Fox TV Episode' [see Montague in this issue], where the corporation was accused of forcing a documentary about rBGH off the air, is but one obvious example. In their book Toxic Sludge Is Good For You, John C. Stauber and Sheldon Rampton recount one episode in 1990 where the corporation's PR firm sent a 'mole' to a meeting of anti-rBGH campaigners. The 'mole', posing as a concerned housewife, was in fact an employee of Monsanto's PR firm Burson-Marsteller, sent to discover in advance what the opposition's tactics would be.(23)

Down at the grassroots, American farmers have reported many instances of Monsanto officials playing down, disguising or trying to cover up the adverse effects of rBGH, including telling farmers that their mastitis problems were unique, or that health problems that arose after using Posilac were the fault of the farmer, rather than the drug.

Monsanto's conduct in this, as in so many other matters relating to rBGH, has been less than honest. Is it surprising then, that their current claims to welcome an 'open debate' about biotechnology are so often taken with several lorryloads, rather than the proverbial 'pinch' of salt?

Paul Kingsnorth is a writer and environmental campaigner. A former journalist at The Independent, he has written for The Guardian, Independent on Sunday, Resurgence, BBC Wildlife and a number of other publications.


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  • A summary of all the available evidence of the vetinerary and public health hazards of rBGH milk from 1985-1998 contained in just under 100 papers published in peer-reviewed journals has been drawn up by Professor Samuel S. Epstein, Professor of Environmental and Occupational Medicine, University of Illinois, School of Public Health, Chicago, and Chairman of the Cancer Prevention Coalition. This summary is being published as an annexe to Professor Epstein's book:
    The Politics of Cancer Revisited, 1998, East Ridge Press, Fremont Center, New York, NY 12736, USA.
    Telephone +1 (914) 887 4589; Fax: +1 (914) 887 6506.

  • For copies of the above, please send a cheque/postal order (made payable to "The Ecologist") for 4 to:
    The Ecologist Editorial Office, Unit 18 Chelsea Wharf, 15 Lots Road, London SW10 0QJ.
    Credit card orders accepted by telephone: 0171 351 3578.

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    1. Schneider, K., "Lines drawn in war over milk hormone", New York Times, March 9, 1994, p.Al2.
    2. Rachel's Hazardous Waste News, No.383, March 31, 1994.
    3. Rachel's Hazardous Waste News, No.384, April 7, 1994.
    4. Rachel's Hazardous Waste News, No.382, March 24, 1994.
    5. Kastel, M.A., Down on the Farm: The Real BGH Story, Wisconsin Farmers Union, 1995.
    6. Op. cit. 4.
    7. Op. cit. 5.
    8. Ibid.
    9. Ibid.
    10. Rachel's Environment and Health Weekly, No.454, August 10, 1995.
    11. Collier, R.J., et al., 'Letter to the Editor', The Lancet, September 17, 1994, Vol. 344, p. 816.
    12. Mepham, T.B., et al., 'Safety of milk from cows treated with bovine somatotropin', The Lancet, November 19, 1994, Vol. 334, pp. 1445-1446.
    13. Challacombe, D.N. and Wheeler, E.E., 'Safety of milk from cows treated with bovine somatotropin', The Lancet, September 17, 1994, Vol. 344, p.8l5.
    14. Mariana Resnicoff and Renato Baserga, 'The Insulin-Like Growth Factor 1 Receptor Protects Tumour Cells From Apoptosis in Vivo, Cancer Research, June 1, 1995, Vol. 55, pp. 2463-2469.
    15. Dr Samuel S. Epstein, 'Unlabelled Milk from Cows treated with Biosynthetic Growth Hormones: A Case of Regulatory Abdication', International Journal of Health Services, 1996, Vol. 26, No. 1, pp. 173-185.
    16. Hankinson, S.E., et al., 'Circulating concentrations of insulin-like growth factor 1 and risk of breast cancer', The Lancet, May 9, 1998, Vol. 351, No. 91 13, pp. 1393-1396.
    17. Chan, J.M., et al., 'Plasma-like Insulin Growth factor-l and prostate cancer Risk: A Prospective Study', Science, January 23, 1998, Vol. 279, pp. 563-566.
    18. Rachel's Hazardous Waste News No. 381, March 17, 1994.
    19. Op. cit. 4.
    20. Ibid.
    21. See Ben and Jerry's website:
    22. Grossman. R., "Corporate Security: Monsanto's first Amendment Right to Lie", Earth Island Journal, winter 1996-7, p.25.
    23. Stauber, J.C. and Rampton, S., Toxic Sludge Is Good For You: Lies, Damned Lies and the Public Relations Industry, Common Courage Press, USA, 1995, pp. 55-59.
    24. Op. cit. 5.

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