Hormones

In order to speed weight gain, many feedlot managers give cattle growth-stimulating hormones - testosterone, estrogens or progestins - in their feed or via a controlled release implant in their ears. [1] The hormones slowly seep into the bloodstream, increasing hormone levels by two to five times. [2]

A substantial portion of the hormones literally passes through the cattle into their feces and ends up in the environment, where it can get into other food and drinking water. The rest of the hormones remain present in beef.

Testosterone, estrogen and progestin are sex hormones produced naturally by the human body and are primarily involved in sexual development. But hormones are very powerful chemicals - a very small increase or a change in the ratio of hormones can produce a huge effect in the body, and there is evidence in both humans and animals that consuming them in the diet can cause prostate and breast cancer and even cause an animal to develop the wrong type of sex organs.

It is estimated that 95 percent of beef cattle in the US are given sex hormones. The EU has banned imports of hormone-treated beef since 1988, but although Europe's beef industry maintains that no steroids are used, it has been reported that there is a black market for these growth promoters for between 5-15 percent of beef cattle. [1]

The use of hormones in organic farming is strictly prohibited, and even in the EU where they are illegal for all types of agriculture, the black market means that the only way for consumers to be confident that their beef is hormone free is to choose organic.

Bumps on the head (left) mark a reproductively active male fathead minnow. Female (middle) sports no such bumps-unless it has been exposed to an androgenic pollutant such as trenbolone (right). These bumps ordinarily show up only on breeding males. The exposed females also produced fewer eggs than unexposed females do. Photos: Ankley et al. 2001. [1]

Environmental estrogen contamination has also been found to cause abnormal growth, sexual development and puberty in humans, [4, 5, 6] and has been linked to fibrocystic disease of the breasts, polycystic ovaries, menstrual irregularities and infertility. [4]

Cancer

The potential effects on human health from hormone residues in beef and beef products include endocrine, developmental and neurobiological, immunological as well as carcinogenic, genotoxic and immunotoxicological effects. [7] Groups most sensitive to the effects of hormones in the diet are unborn babies, prepubescent children, women (to the effects of testosterone) and men (to the effects of estrogen). And the effect of a mixture of low levels of different estrogenic chemicals is greater than the effects of each individually. [8]

A European Commission report [9] has found a spatial and temporal correlation between treating cattle with hormones and the growing incidence of breast and prostate cancer and food allergies. [10, 11, 12]

The synthetic hormone diethylstilbestrol (DES), banned by the US Food and Drug Administration (FDA) in the 1970s, used to be given to chicken and cattle. This synthetic estrogen fostered the development of cancer in women. [1]

IGF-1

When a cow is injected with a hormone called Recombinant Bovine Growth Hormone (rBGH), it stimulates production of another hormone called Insulin-Like Growth Factor I (IGF-I). IGF-I is produced naturally in both humans and cows, but increased levels of this hormone are believed to be the leading risk factor for prostate and breast cancer. [13]

Men with high blood-levels of IGF-I are over four times more likely to develop prostate cancer than are men with lower levels. Prostate cancer is now the commonest type of cancer in non-smoking men, with an estimated 185,000 new cases and 39,000 deaths in 1990.

Women with a relatively small increase in IGF-I are up to seven times more likely to develop pre-menopausal breast cancer than women with lower levels. Evidence also suggests that IGF-I increases the risk of childhood cancers.



Monsanto's rBGH

rBGH (also known as Bovine Somatotropin, BST or Posilac) is manufactured by Monsanto and is a genetically engineered copy of a naturally-occurring hormone produced by cows. The side effects associated with rBGH are so numerous and so potentially dangerous that it is banned in Canada, the European Union and a number of other countries. However, rBGH has been in use in other places, particularly the US, for some years. [13]

Side effects for the cow

Animals treated with rBGH undergo immense stress. 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. [13]

The label on Posilac warns of 21 cattle health problems associated with its use, including cystic ovaries, uterine disorders, decreased gestation period, decreased calf birth weight, increased twinning rates and retained placenta. Other problems include abortions, open sores and deformed calves.

The most widely reported and 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 with a high proportion of pus, and mastitis can thus be a serious source of lost revenue to the dairy farmer. Many farmers try to solve the problem by using antibiotics, but antibiotic residues in milk are suspected of causing health problems in humans who drink it and contributing to the spread of antibiotic resistant bacteria.


Side effects for the milk drinker

Apart from the ill effects of drinking antibiotics or pus, rBGH has also been linked to cancer. In 1993, Monsanto had admitted that rGBH increases the level of IGF-I in milk by about five-fold, though it has been estimated that this figure may be up to ten-fold. [13]

IGF-I is not destroyed by pasteurization or digestion in the stomach and is easily absorbed by the human body. Unpublished tests by Monsanto revealed "significant growth stimulating effects" (which can lead to cancer) in organs of adult rats fed very low doses of IGF-I.

Researchers at the University of Illinois, Chicago have reported that IGF-I from rBGH treated cows may lead to breast and colon cancer in human milk-drinkers. Another study published in The Lancet found a seven-fold increase in the risk of breast cancer among pre-menopausal women with high levels of IGF-I in their blood. A study published in Science found a four-fold increase in the risk of prostate cancer among men with high levels of IGF-I in their blood.


Unnecessary

Daily injections of rBGH increase a cow's milk yield by between 10 and 20 percent. But since the 1950's, US dairies have been producing more milk than the country can drink and the government must buy the surplus to prevent the price from plummeting. rBGH generates an annual income of between US$ 300 and $500 million for Monsanto. [13]

Unwanted

Surveys have shown that more than 70 percent of American consumers do not want to drink rBGH milk, but they are denied a legal right to know how their milk is produced. Since 1994, retailers were threatened with legal action if they labeled milk as "rBGH free." The FDA explained that there was "virtually" no difference between rBGH milk and ordinary milk and that labeling would thus unfairly discriminate against companies like Monsanto.

In April 1994, Monsanto won a lawsuit against the State of Vermont, where rBGH was legally required to be labeled, on the grounds that the "unconstitutional" law violated the First Amendment, which asserts a constitutional right not to be forced to disclose information.

Monsanto has now reluctantly abandoned its lawsuits against retailers, and labeling milk 'BGH-free' is now permitted in the US. But the FDA still refuses to require producers to so label their milk, so even now, many people have no idea what they are really drinking.

Untested

rBGH was never properly tested before being approved by the FDA. A standard cancer test of a new human drug requires two years of testing with several hundred rats. But rBGH was tested for only 90 days on 30 rats. [13] This study was never published and the FDA has refused to allow anyone outside the administration to review the data, saying it would "irreparably harm" Monsanto.