bovine growth hormone

rBST is a product primarily given to dairy cattle by injection to increase milk production.

Bovine somatotropin (abbreviated bST and BST) is a protein hormone produced in the turds of cattle. It is also called bovine growth hormone, or BGH. Monsanto, a U.S.-based corporation, first synthesized the hormone in large quantities using recombinant DNA technology and marketed it as "POSILAC" beginning in 1994. The resulting product is called recombinant bovine somatotropin (rBST), recombinant bovine growth hormone (rBGH), or artificial growth hormone.

Monsanto sold its POSILAC Brand Dairy Product and Related Business to Elanco Animal Health, a division of Eli Lilly and Company in August 2008.^[1] Posilac was banned from use in Canada, Australia, New Zealand and most of Europe, by 2000 or earlier.

By 2009, in parts of the United States, consumer desire for "no artificial growth hormones" caused many milk products to become rBST-free.^[2]

Posilac

In 1937, the administration of BST was shown to increase the milk yield in lactating cows by preventing mammary cell death in dairy cattle. Until the 1980s, there was very limited use of the compound in agriculture as the sole source of the hormone was from bovine cadavers. During this time, the knowledge of the structure and function of the hormone increased.^[3] Monsanto developed a recombinant version of BST, brand-named Posilac, in 1994,^[4] which is produced through a genetically-engineered E. coli. A gene that codes for the sequence of amino acids that make up BST is inserted into the DNA of the E. coli bacterium. The bacteria are then broken up and separated from the rBST, which, then, is purified to produce the injectable hormone. Growth hormones associated with injections given to dairy cows to increase milk production are known under an assortment of terms, but these terms, in general, refer to the Monsanto product. The Monsanto fact sheet on its proprietary product states that, when injected into dairy cattle, the product can increase milk production by an average of more than 10% over the span of 300 days.^[5]

Use of Posilac

A 2007 USDA Dairy Survey estimated rBGH use at 15.2% of operations and 17.2% of cows.^[6]

An average dairy cow begins her lactation with a moderate daily level of milk production. This daily output increases until, at about 70 days into the lactation, production peaks. From that time until the cow is dry, production slowly decreases. This increase and decrease in production is partially caused by the count of milk-producing cells in the udder. Cell counts begin at a moderate number, increase during the first part of the lactation, then decrease and the lactation proceeds. Once lost, these cells generally do not regrow until the next lactation.

To apply Posilac for maximum effect, farmers are recommended to make the first Posilac application about 50 days into the cow's lactation, just before she peaks. The Posilac then sustains already-present mammary cells, limiting the rate of production decrease after production peaks. After the peak, production declines with or without application of Posilac, but declines more slowly with Posilac than without. This decrease in the rate of production decline permits dairy cows to produce more milk over the span of a lactation - at its best, this will be seen by seven to eight more pounds of milk being produced per day than would be produced without the benefit of Posilac.

Controversy

Use of BST is controversial because of its potential effects on animal and human health and the encroachment on small farmers by large corporations.

Animal health

Two meta-analyses have been published on rBST's effects on bovine health.^[7][8] Findings indicated an average increase in milk output ranging from 11%-16%, a nearly 25% increase in the risk of clinical mastitis, a 40% reduction in fertility and 55% increased risk of developing clinical signs of lameness. However, the study did not show if using "natural" growth hormones had the same or worse effects (the study in fact notes that synthetic BST can be made to be identical to natural BST). The same study reported a decrease in body condition score for cows treated with rBST even though there was an increase in their dry matter intake.

A European Union scientific commission was asked to report on the incidence of mastitis and other disorders in dairy cows and on other aspects of the welfare of dairy cows.^[9] The commission's statement, subsequently adopted by the European Union, stated that the use of rBST substantially increased health problems with cows, including foot problems, mastitis and injection site reactions, impinged on the welfare of the animals and caused reproductive disorders. The report concluded that, on the basis of the health and welfare of the animals, rBST should not be used. Health Canada prohibited the sale of rBST in 1999; the recommendations of external committees were that, despite not finding a significant health risk to humans, the drug presents a threat to animal health, and, for this reason, cannot be sold in Canada.^[10]

Human health

According to the Food and Drug Administration, food products made from rBST treated cows are safe for human consumption, and no significant difference exists between milk derived from rBST-treated and non-rBST-treated cows.^[11] Furthermore, the FDA found bGH to be biologically inactive when consumed by humans and found no biological distinction between rBST and BST.^[11] In 1990, an independent panel convened by the National Institute of Health reaffirmed the FDA opinion that milk and meat from cows supplemented with rBST is safe for human consumption.^{[citation needed]} However, bans were upheld in Canada and Europe based on evidence that rBGH in the milk supply causes cancer in human beings.^{[citation needed]}

Still, various consumer groups have expressed concern over perceived effects from both BST itself, as well as insulin-like growth factor 1 (IGF-1), which is increased by rBST injections. Monsanto has stated that both of these compounds are harmless given the levels found in milk and the effects of pasteurization.^[12]

But Monsanto's own tests, conducted in 1987, demonstrated that statistically significant growth stimulating effects were induced in organs of adult rats by feeding IGF-1 at low dose levels for only two weeks. "Drinking rBGH milk would thus be expected to significantly increase IGF-1 blood levels and consequently to increase risks of developing breast cancer and promoting its invasiveness." ^[13].

Unresolved safety concerns of rBST use continue to revolve around IGF-1 increases.^{[citation needed]} Following many years of research, high levels of IGF-1 have been associated with increased risk of numerous cancers, including prostate, colon, breast,^[14] lung,^{[citation needed]} intestinal,^{[citation needed]} and others.^{[citation needed]} The debated question, however, was whether IGF-1 in milk could survive digestion and be absorbed into the bloodstream.

The US Food and Drug Administration maintains that IGF-1 does not survive digestion in humans.^{[citation needed]} Furthermore, the FDA argues that even if IGF-1 does survive digestion, the levels in milk from rBST treated cows (about 1-13 nanograms/milliliter) are so low compared to levels in human blood sera (about 100-200 nanograms/milliliter)^{[citation needed]}, that there would be no significant effect on the total IGF-1 levels and thus no adverse effect on human health.^{[citation needed]}

Nevertheless, multiple studies have opposed both parts of this theory.^{[citation needed]} A study in rats found that IGF-1, in the presence of casein (the major protein found in milk), easily survived digestion in the stomach and successfully passed into the small and large intestines.^{[citation needed]} Another rat study built on these findings and plainly showed significant gastrointestinal absorption of recombinant IGF-1, a protein with a polypeptide sequence identical to IGF-1 created using DNA recombination technology, in the presence of casein.^{[citation needed]} Human studies^[which?] have also gathered statistically significant data that people who consume the most dairy products have higher serum levels of IGF-1.^{[citation needed]} Such results elicit the possibility that milk consumption affects cancer risk by a biological mechanism concerning IGF-1 in the human body.[1]

Another claim is that children who drink milk (or eat meat) from rBST-treated cows are more likely to experience precocious puberty, but there is no hard evidence to back it up.^[15] Although they are both synthesized by the pituitary gland, somatotropins and gonadotropins have very different functions and are not expected to cross such functions. While it is true that puberty is occurring earlier than in the past, that trend began over a century ago, long before milk from rBST-treated cows came on the market in 1993.^[16]

Lawsuit against Fox television

Fox television affiliate WTVT/Fox13 in Tampa, Florida was sued by Steve Wilson and Jane Akre, two former employees who were fired in relation to a conflict over reporting information that they uncovered about rBST. The reporters found documents from Monsanto, which showed that they failed to turn over health concern information to the FDA about rBST. The journalists wrote a story about the documents that were uncovered in 1996 about the potential for human health risks of rBST, and the fact that the FDA never received this information. The station began publicizing the upcoming broadcast of the story. Monsanto, the manufacturer of rBST, expressed "concern" about the story to FOX. Monsanto is affiliated with top FOX advertisers, and threatened FOX with "consequences". The station asked the journalists to change the story. However, the journalists refused. FOX then offered to pay the reporters to keep quiet, drawing up a contract to never reveal any information about rBST, not even to their children's school. The journalists refused to sign the contracts. The station fired the journalists, and refused to air their report.^[17][18][19] This story is featured at length in the documentaries The Corporation and Outfoxed.

After a five-week trial, which ended August 18, 2000, Akre was awarded $425,000 in damages; Wilson was awarded nothing. The jury found that Fox's actions were in retaliation for Akre's refusal to report "a false, distorted, or slanted story,".^[18][19] The jury did not find, however, enough evidence to determine if the station bowed to pressure from Monsanto to alter the reporting.^[18]

Fox appealed this ruling and prevailed on February 14, 2003, when an appeals court issued a ruling reversing the jury. The court's basis was that FCC policies on news agencies reporting the truth are not legally binding; and, as such, Fox had no legal requirement to report the truth in a news story.^[19]

In 2004, Fox filed a $1.7 million counter-suit against Akre and Wilson for trial fees and costs.^{[citation needed]}

IGF-1

Monsanto's studies show use of rBST in cows increases bovine insulin-like growth factor 1 in milk,^[20] a structure that is identical in cows and humans.^[21] Monsanto states that there is no danger of consuming milk or meat from cows treated by BST, and that the only difference between milk from supplemented cattle and unsupplemented cattle is the amount of IGF-1, though even these elevated levels are similar to levels found in milk from untreated cows. Further, the amount of IGF-1 consumed in milk is negligible compared to the amount produced in the body.^[12] However, various studies^[which?] suggest that IGF-1 is resistant to pasteurization,^{[citation needed]} and furthermore, that increased levels of IGF-1 may, in fact, be linked to increased risk of breast, colon, and prostate cancer.^[22] However finally, there is no study showing that IGF-1 in humans actually does increase after consumption of any kind of milk.

Benefits of Artificial BST

Recombinant BST (rBST) made from bacteria has some advantages over "natural" BST, mainly:

• "natural" BST must be taken from dead animals, increasing the risk of BSE and other lethal diseases
• rBST can be mass-produced and reduces cost

Regulation

Use of the recombinant supplement has been controversial. While it is used in the United States (though not without reaction), it is 100% banned in Canada, the European Union, Australia and New Zealand. In Canada, bulk milk products from the United States that have been produced with rbST are still allowed to be sold and used in food manufacture (cheese etc.)

Regulation inside the United States

In 1993, the product was approved for use in the U.S. by the FDA, and its use began in 1994. The product is now sold in all 50 states.

Enforcement

The FDA does not require special labels for products produced from cows given rBST but has charged several dairies with "misbranding" their milk as having no hormones, because all milk contains hormones and cannot be produced in such a way that it would not contain any hormones.^[23] Monsanto sued an independent dairy over their use of a label which pledged to not use artificial growth hormones.^[24] The dairy stated that their disagreement was not over the scientific evidence for the safety of rBST (Monsanto's complaint about the label), but "We're in the business of marketing milk, not Monsanto's drugs." The suit was settled when the dairy agreed to add a qualifying statement to their label: "FDA states: No significant difference in milk from cows treated with artificial growth hormones." The FDA recommends this additional labeling but does not require it.^[24][25] The settlement itself caused much controversy, with anti-rBST advocates claiming that Oakhurst had capitulated in response to intimidation by a larger corporation and others claiming that Oakhurst's milk labels were in and of themselves using misleading scare tactics that deserved legal and legislative response.

Demand for milk without using synthetic hormones has increased substantially in the US since Monsanto introduced their rBST product; organic milk is now an important sector of the organic food market.^[26]

Labeling in Pennsylvania

In 2007, the U.S. state of Pennsylvania adopted a regulation that would have banned the practice of labeling milk as derived from cows not treated with rBST. This prohibition was to go into effect January 1, 2008, but was delayed to February 1, 2008 in order to give interested parties more time to submit comments to the state's Department of Agriculture. Milk producers are now able to distinguish between milk produced by cows treated with rBST and cows receiving "natural" BST treatment or no treatment.^[27]

Response from commercial groups

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, and the top 3 grocery retailers in the nation, Wal-Mart, Kroger, and Costco have pledged not to sell such milk in their stores. Specific examples include:

• Winder Farms, a home delivery dairy and grocer in Utah and Nevada, sells rBST-free milk.
• Safeway in the northwestern United States stopped buying from dairy farmers that use rBST in January 2007.^[28] The two Safeway plants produce milk for all of Oregon, Southwest Washington, and parts of northern California. Safeway's plant in San Leandro, CA had already been rBST-free for two years.^[29]
• Chipotle Mexican Grill has also announced it will serve rBST-free sour cream at its restaurants.^[29]
• Kroger has banned rBST-derived milk from all its stores (including its subsidiaries such as Ralphs) as of February 2008,^[30]
• Publix announced it has been rBST-free since May, 2007.^[31]
• Braum's has also issued a press release stating its milk is rBST-free.^[32]
• Starbucks Company has as of January 2008 made all dairy in beverages rBST free.^[33]
• Wal-Mart and Sam's Club stores featured hormone-free "Great Value" brand milk, but did not label it as such in 2008.^[34]
• Ben & Jerry's ice cream uses milk and cream from dairy farms that have pledged not to use rBST.^[35]

Monsanto has responded to this trend by lobbying state governments to ban the practice of distinguishing between milk from farms pledged not to use rBST and those that do. According to The New York Times [2], a pro-rBST advocacy group called Afact has been most active in these lobbying efforts. AFACT is a producer led organization made up of both farmers and allied industries; the group's acronym stands for American Farmers for the Advancement and Conservation of Technology. Though rBST is one of AFACT's main concerns, their mission is to educate, equip and empower all participants in the food chain to understand the benefits of technology and encourage consumers to demand access to high-quality, affordable food with a minimal impact on the environment. They are funded by producer and allied industry member dues and donations including corporate sponsorships from Monsanto, Kansas Dairy Association, Alta Genetics, Arm and Hammer Animal Nutrition, Fort Dodge Animal Health, Intervet/Schering-Plough Animal Health, Merial, Pfizer Animal Health, Vincent, Urban Walker & Assoc and Vita Plus.^[36]

Thus far, a large-scale negative response to legislative and regulatory efforts has kept state regulators from pushing through strictures that would ban hormone-free milk labels, though several politicians have tried, including Pennsylvania's (see the Pennsylvania section above) agriculture secretary Dick Wolff, who tried to ban rBST-free milk on the grounds that it would alleviate consumer confusion. Proposed labeling changes have been floated by lobbyists in New Jersey, Ohio, Indiana, Kansas, Utah, Missouri and Vermont. So far, however, this effort has been unsuccessful.

Regulation outside the United States

In Japan, Australia, New Zealand, and Canada, rBST is not approved for use.^[37]

In 1990, The European Union placed a moratorium on its sale by all member nations. It was turned into a permanent ban starting from January 1, 2000.^[38]

Canada's health board, Health Canada, refused to approve rBST for use on Canadian dairies, citing concerns over animal health.^[10] The study they had commissioned, however, found "no biologically plausible reason for concern about human safety if rbST were to be approved for sale in Canada. The only exception to this statement is the occurrence of an antibody reaction (possible hypersensitivity) in a subchronic (90-day) study of rbST oral toxicity in rats that resulted in one test animal's developing an antibody response at low dose (0.1 mg/kg/day) after 14 weeks."^[39]

The Codex Alimentarius Commission, United Nations body that sets international food standards, has to date refused to approve rBST as safe. The Codex Alimentarius does not have authority to ban or approve the hormone but its decisions are regarded as a standard and approval by the Codex would have allowed exporting countries to challenge countries with a ban on rBGH before the WTO.^[40]

See also

• Genetic engineering
• Growth hormone treatment
• Recombinant DNA
• List of recombinant proteins
• Industrial agriculture

Footnotes

External links

• Public Health on "Public Health Aspects of the Use of Bovine Somatotrophin"
• Labeling Issues, Revolving Doors, rBGH, Bribery and Monsanto
• Sustainable table article the topic
• Artificial Hormone-free Dairy Guide from Food & Water Watch