Bovine Growth Hormone: A Political, Economic, Ethical and Health Issue

WHEN THE FOOD AND Drug Administration approved the first major agricultural biotechnological product -- Bovine Growth Hormone (BGH) or Bovine Somatotropin (BST) -- for use in November 1993n the tremendous amount of opposition and controversy it generated was probably not fully anticipated. This genetically engineered product is produced by inserting the cow's BGH-making gene into the genetic code (its DNA) of a common strain of bacteria.(1n2)

BGH is not the first genetically engineered product; there are at least 22 that are currently in use.( 2) Mostn howevern are medications like insulin for treating diabetics or interferon for treating cancer.( 2) There are other foods that have been genetically engineeredn such as an enzyme called chymosin that is an exact replica of the animal enzyme renninn which comes from the stomach lining of calves. This is used to coagulate milk in the production of cheeses.( 2) Another genetically engineered product is the Flavr Savr tomaton which slows down the aging process and the mushy texture of the tomato.( 2)

BGH is a natural protein hormone that is produced in the pituitary gland of cattle; it is involved in regulating fatn carbohydrate and protein metabolism.( 3) It is also produced during lactation in order to stimulate milk production.( 4) The genetically engineered version is nearly identical to the natural one and increases milk production by 10 percent to 25 percent.( 4) Monsanton a St. Louis-based chemical companyn invested more than $300 million in the development of BGH and was the first manufacturer to obtain FDA approvaln( 1) but three other companies -- American Cyanamiden Elanco (a division of Eli Lilly and Co.) and Upjohn -- have all been granted approval.( 3)

Four primary issues -- politicaln economicn ethical and health -- are intertwined in this hotly-debated product.


This is a rather complex issue and appears that not all the information on the studies had been released at the time the FDA's researchers and other scientists were examining BGH. Even though this drug has been scrutinized by the FDA more so than othersn there remain many concerns and questions.

The U.S. Congress responded by asking the National Institutes of Health (NIH) to appoint an independent panel to examine the available data on BGH.( 5) Its conclusion was that the overall composition and nutritive quality of the BGH-treated milk did not differ from that of nontreated milk.( 5) Others contend that the conclusion is not based on the totality of evidence because Monsanton the company that funded a major study at the University of Vermontn refused to release the animal health data to Vermont's Senate and House Committees on Agriculture.( 6) A spokeswoman for the company statedn "Why should we leave it open to someone who has not been involved with the study to interpret? That doesn't make any sense."( 7)

At the time that the panel convenedn it was not able to review the unpublished data becausen by lawn the FDA cannot release it before making a final decision.( 5) And the panel was appointed in 1990 -- before the FDA gave its final approval. The panel did attest that its conclusion may have been compromised due to not reviewing the unpublished datan yet it stood firm on its conclusion: The hormone does increase milk production and is safe for human consumption.( 5)

Most consumersn including registered dietitians and Congressn are opposed to the FDA law stating that the BGH-treated milk is not subject to labeling. The FDA requires labeling of the milk (or any bioengineered food) only if the nutritional value or toxin level is significantly altered or if the food has been given a substance that is known to cause an allergic reaction.( 2) An advisory committee to the FDA met on the issuen and more than two-thirds of the committee was against mandatory labelingn contending that the differences in the treated and nontreated milk are not discernible in terms of nutritional compositionn qualityn taste and texture.( 3) Committee members also stated that the FDA lacks the authority to require labelingn given that BGH is already present in nontreated milk.( 3)

This labeling law will probably change due to Congress' opposition as well as a consumer boycott of those foods by the Pure Food Campaign.( 3) Until thenn howevern the FDA allows manufacturers to state on food labels that their foods are not bioengineered butn in most casesn only if an additional statement is made that the food is no safer than the genetically engineered version.( 2)


This product has some important implications. Our government already spends millions of dollars for the purchase of surplus dairy products( 8) ($10.6 billion over the last decade); it is projected that the use of BGH may cost the government about $15 million annually in the purchase of an even greater surplus.( 9) Consistent with the supply-and-demand theoryn this greater surplus will drive the price of milk and other dairy products downn forcing some small dairy farmers out of business.


The cows already work hard and will be working even harder with the increased milk productionn possibly increasing the incidence of mastitisn an inflammation of the udder (mammary glands) which can increase their discomfort and stress level.

The results of the Monsanto-sponsored study in Vermont were published in December 1992 (after a refusal to release the results in October 1991 under Monsanto's orders) and did show a fourfold increase in antibiotic treatment for mastitis in BGH-treated cows versus untreated cows. The average length of treatment for the mastitis-infected cows was six times longern and seven times more milk was discarded from BGH-treated cows than from untreated ones.

The mastitis problem appears to have been influenced by several factors: ( 1) a four-year lag time between the completion of the experiment and publication of the study; ( 2) refusal to relinquish the data to the Vermont legislature and the U.S. General Accounting Office (GAO)n the "watchdog" for Congress; and ( 3) the study's results were not made available to the Veterinary Medicine Advisory Committee.( 6) Some may argue that the discomfort in animals is justified if some benefit is gained by humans. Subjecting the cows to frequent injections is certainly another animal welfare concern and may be cruel to the animals.


This is a most complex and confusing issuen with a wide range of views and conclusions. Many scientific experts are not convinced of BGH's ill health effectsn as claimed by opponents. This product has been deemed safe by several national health organizationsn including the FDAn the National Institutes of Healthn the Department of Agriculturen the American Dietetic Associationn the American Medical Associationn the American Academy of Family Physicians Foundation and the American Academy of Pediatrics.( 4)

Yetn vocal opponents like Jeremy Rifkinn who founded the Pure Food Campaign and is leading the charge against biotechnologyn( 2) and an environmentalist named Epstein raise serious questions concerning the hormone's safety. For several yearsn Rifkin has asked the FDA to require large-scale studies of the toxicological effects of BGH on cows. He contendsn after reviewing the studiesn that uncertainties exist about whether the hormone stimulates premature growth in infants and breast cancer in women( 10) by the increased levels of a second growth hormone called insulin-like growth factor-I (IGF-I)n found in BGH-treated milk.( 5)

IGF-I is the chemical that mediates much of the cellular response to growth hormones in cows and the effects of growth hormones in humans.( 11) IGF-I survives the pasteurization processn but it is destroyed by the processing of infant formulas.( 12)

Both hormones (in cows and humans) are identicaln according to a study done in 1986. Increased levels in humans may cause acromegaly (enlargement of handsn feet and facial features)n glucose intolerancen high blood pressure and possibly cancer and tumor growth.( 11) IGF-I may be linked to cancer and tumor growth as well.( 11) The cell proliferation that occurs with IGF-I is purported to increase cancer cells.( 12) Industry studies did find significant increasesn from 25 percent to 70 percentn in BGH-treated milk.( 11) Another studyn in 1989n found that the increases in IGF-I were at least 3.2 times higher in cows treated with BGH for only one week than found in the milk of untreated cows.( 11)

Howevern a panel of scientistsn veterinarians and a dairy farmer appointed by the NIH reviewed the published studies( 5) and listened to all sides (scientistsn consumer activists and drug company officials). They did not see this as a cause for concern since the amount that is in milk is less than what is typical in adults' saliva.( 5) Alson the amount of IGF-I in breast milk contains as much or more than BGH-treated cows.( 12) The wide variance in measured IGF-I levels in different studies can partially be explained by the low reliability of the methods used by several researchersn including the original developer.( 11)

Rifkin charges that the manufacturers of BGH have manipulated published data on its effects on human health and have withheld the study's data showing the ill effects in cowsn including lesions and infectious disease.( 10) His contention of ill health effects on humans is countered by the FDA and other scientists explaining that the hormone is orally inactive because it is a protein that is subjected to digestive enzymes that break down proteinn( 12) just as it does any time protein is ingested.

Studies in which children were given intravenous (IV) injections of the hormone in efforts to treat dwarfism saw no activity. Additionallyn studies of ratsn which were known to respond to IV dosesn noted no biological effectsn( 10) In addition to digestionn which renders it biologically inactiven it has been known for nearly 40 years that this hormone derived from animals is inactive in humansn even when injected. The reason is that the amino acid sequence of the animal-derived hormone differs from that of the human-derived hormone (somatotropin)n which means that the former cannot bind to the receptors on human cells. Thereforen the biological effects of the hormone cannot be mediated.( 12)

BGH is not just in the milk from the cows injected with the hormone; it is in all cows' milk and ranges from 1-10 ng/mL -- a minuscule quantity.( 12) When the milk is pasteurizedn 90 percent of the BGH in milk is destroyed.( 13)

A primary concern with BGH-treated milk is the indirect effect it has in causing a person to become resistant to prescribed antibiotics for an infection/illness. When a cow is made to produce more milk (which is what BGH does)n it has an increased risk of getting mastitis (inflammation of the mammary glands). The treatment for mastitisn like any infectionn is with antibiotics; and drug residues can make their way into the cow's milk.( 4) If enough of the BGH-treated milk with antibiotic residual is consumedn the bacteria that caused the human infection may become resistant to the antibiotic that the human is taking to ward off the infection. This can occur in anyone who has had repeated exposures of a particular antibiotic.( 4)

Howevern when cows are treated with antibioticsn they are supposed to be taken out of the milking line for a sufficient time period so that the antibiotic residuals will be "flushed" out.( 4) And although there is not a federal representative at each dairy farm monitoring thisn there are steps taken by the government that would discourage this practice.( 4) Those stepsn which include discarding the antibiotic-laced milk without receiving payment and a possible finen may not be stringent enough to completely discourage all dairy farmers.( 4)

The use of antibioticsn howevern is not limited to just FDA-approved ones. Of the 82 drugs that are known or suspect for leaving residues in milkn only 30 are approved by the FDA for use in dairy cows.( 6) According to many veterinarians treating dairy cowsn 40 percent to 85 percent of the antibiotics prescribed are not approved. Compounding this illegal use of antibiotics is the inadequate job that the FDA admits to in not being able to effectively "police" the residue testing in milk.( 6) An established tolerance is set for 35 of the 82 potential drugs used. Howevern state agencies typically test for only four of these drugsn all of which are in the penicillin family.

In a 1992 report by the GAOn the investigative arm of Congressn the FDA was criticized for not developing a comprehensive strategy for monitoring the animal drug residues in milk.( 10) The agency did expand its residue-monitoring program to test 12 drugsn but it is still only able to analyze about 500 or so samples annually.( 6) So farn these monitoring programs have not detected any serious drug residue levelsn but many drugs are being bypassed for testing because many FDA non-approved drugs are being usedn and reliable testing can only be done for about 12 drugs.( 6)

Another concern is the animal and human health hazard posed by the change in diet for BGH-treated cows. Cows receiving the hormone require a more energy-dense diet due to the increased milk production. Protein and energy supplements that come from rendering animals provide the extra nutrient and caloric needs in the BGH-treated population. There is concern that some of the rendered animals used for the development of the nutritional supplement may be contaminated with a disease called bovine spongiform encephalopathy (BSE)n which may be accelerated with BGH.( 6)

A group of degenerative diseases that affects the central nervous systemn especially the brainn occurs in animals and humans and has been shown to be transmissiblen in partn by eating the meat of the infected animal.( 6) The diseases are fataln and symptoms develop within two to eight years after the animal was infected. As of 1993n more than 80n000 cows were diagnosed with the condition in England. It appears that the ingestion of protein supplements (mostly meat and bone meal) caused the cattle to contract disease.( 6)

Although at this point evidence was lacking that BSE could affect humansn a precautionary measure was adopted in July 1988n whereby the feeding of sheep and cow brains and organs to cows and humans was prohibited in Englandn Francen Switzerland and Ireland -- areas of Europe where BSE was confirmed.( 6)

A letter was sent by the director of the FDA's Center for Foodn Safety and Applied Nutrition to dietary supplement manufacturers to look at their sources of sheep and cow neural and glandular material.( 6) The national average for all dead cattle being rendered and used as protein supplements is 14 percent.( 6)

It appears thatn although U.S. officials said no cases of BSE exist in the U.S.n there are 100n000 apparently healthy cows that die rather abruptly each year. The symptoms are different than what the cows in England experiencedn so it is believed that a different strain may be affecting the cows in the U.S.( 6)


Although this topic incorporates many different and complex issuesn the conclusion seems rather simple. The product is just not necessary! Even if all researchersn scientistsn food safety activistsn veterinarians and government officials were in agreement as to BGH's safety and efficacyn the fact that our government spends millions of dollars purchasing its existing surplus certainly lends no support to a product that increases the production of that surplus product!

(1.) Anonymousn "Drugs to Boost Milk Output OK'dn" The Press Democratn Nov. 6n 1993.

(2.) Schardtn D.n "Diving Into the Gene Pooln" Nutrition Actionn 21:6n July/August 1994.

(3.) Gershonn D.n FDA Panel Sees Problems With Labelling of Milk Hormonen" Naturen 363:13n May 3n 1993.

(4.) Anonymousn "New Cries Over How the Milk Spillsn" Tuffs Univ. Diet and Nutrition Letter 12:2n April 1994.

(5.) Gibbonsn A.n "NIH Panel: Bovine Growth Hormone Gets the Nodn" Sciencen Vol. 250n 1990.

(6.) Hansenn M.K.n Testimony before the Veterinary Medicine Advisory Committee on Potential Animal and Human Health Effects of rbGH Usen Consumer Policy Instituten Consumers Unionn March 31n 1993.

(7.) Sibbisonn J.B.n "Safety of Bovine Growth Hormonen" The Lancet Vol. 338n Dec. 14n 1991.

(8.) Hastingsn J.n "Is Milk From Hormone-Treated Cows Safe?" Health March/April 1994.

(9.) Gershonn D.n "Prospects for Growth Hormone Turn Sour" Nature Vol. 364n Aug. 12n 1993.

(10.) Gershonn D.n "Bovine Growth Hormone Meets New Safety Concernsn" Nature Vol. 358n Aug. 20n 1992.

(11.) Hansenn M.K.n and Hallorann J.M.n Correspondence to the Office of the Commissionern FDAn May 24n 1993.

(12.) Ethertonn T.D.n Kris-Ethertonn EM.n and Millsn E.W.n "Recombinant Bovine and Porcine Somatotropin: Safety and Benefits of These Biotechnologiesn" JADA 93:2n Feb. 1993.

(13.) Juskevichn J.C.n and Guyern C.G.n "Bovine Growth Hormone: Human Food Safety Evaluationn" Sciencen Vol. 249n Aug. 24n 1990.

Life University.


By Julane R. Contursi

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