ENVIRONMENT: Mad Cows And Growth Hormones Part Of The Same Problem

By IPS Correspondents Reprint | | Print |

Analysis Judith Perera

LONDON, Mar 25 1996 (IPS) - The spread of Bovine Spongiform Encephalopathy (BSE), or so-called ‘Mad Cow disease’ may have been encouraged by western industry’s increasing use of artificial growth hormones to boost profitable milk and meat production.

The issue was raised in the U.S. as early as 1993 by Michael Hansen, Research Associate at the Consumer Policy Institute, during testimony before the Veterinary Medicine Advisory Committee on Potential Animal and Human Health Effects of Use.

Cows treated with growth hormones (rBGH) require more energy- dense food. This has usually been provided as meat and bone meal derived from ‘rendered’ animals — animal bodies processed into food for other animals).

As well as the problems arising from sheep suffering from the BSE- related disease of scrapie, Hanson pointed out, this includes ‘downed cows’ — apparently healthy cows that simply drop dead. He also noted that researchers had begun to suspect a link between BSE and downed cow deaths.

Mammals contract BSE by eating infected meat, which raises the possibility that BSE infection may be carried into rendered animal- based feed given to rBGH-injected cows.

Bovine Growth Hormone (BGH) or Bovine Somatotropin (BST) is a natural protein made by cows. Recombinant BGH (rBGH) is a genetically engineered, synthetic version of the hormone, developed and tested over the past 10 years by drug and chemical companies such as Monsanto, Upjohn, Eli Lilley and American Cyanamid.

It is injected every 14 days into dairy cows for 200 days of a cow’s 335-day lactation cycle and increases milk production dramatically.

The use of rBGH was approved by the U.S. Food and Drug Administration (FDA) in November 193 but its use is banned in many European countries, Australia and New Zealand.

There is mounting evidence that it may compromise the health of both cows and humans. But intensive lobbying by the chemical companies have helped ensure widespread use in the U.S. and Britain.

Now it is being promoted heavily in many developing countries as a solution to food shortages. But this could be a false economy for the developing world.

Under rBGH treatment cows are kept in a perpetual cycle of gestation and lactation which wears out their bodies quickly, cutting the normal life span of 20 to 25 years to five or less.

Already, cows are overproducing milk. In 1930, the average cow produced five kilograms of milk per day, but by 1988, milk production was at 18 kilogrammes a day. With rBGH injections it rises to 22 kilogrammes per day.

It is because rBGH-injected cows cannot consume and digest enough normal food to support this level of production that they are fed a highly concentrated diet. They are also more vulnerable to disease because their bodily systems are overworked. Thus they are often given increased doses of antibiotics to cope with the disease.

Residues from the disease and from the drugs then get into the milk. This added stress on cows lowers fertility as well as life span, reducing the number of calves each cow can produce.

British scientists Dr Eric Millstone and Dr Eric Bruner, hired by Monsanto to review data on rBGH, say they were prevented from releasing findings that showed a definite increase in cases of mild inflammation of the mammary glands (mastitis) in rBGH treated cows.

“I find it very curious that Monsanto should object to our paper — a relatively harmless analysis which shows some small negative effects,” says Bruner. “If they’re seeking to suppress these data, as they have for the last three years, then could it be that there are other questions which we don’t yet know about?”

One major worry is that hormonal and antibiotic residues in milk and meat (a large percentage of hamburger meat is made from “burned out” dairy cows) will affect human health, especially children.

An earlier onset of puberty is thought to be caused by the already increased use of hormones in cows, and girls who menstruate before the age of 12 have a higher risk of contracting breast cancer later.

The increase in antibiotic use in animals also adds concern about increased antibiotic-resistant bacteria.

Cows injected with rBGH produce much more of an insulin-like growth factor known as IGF-1. Its molecular structure is the same in humans and cows, increasing the likelihood of transmission through milk and meat consumption.

In humans, IGF-1 is linked to acromegaly, a disease involving the abnormal enlargement of the hands, feet, nose and chin. Increased levels of IGF-1 have also been linked to colon tumours and cancer, particularly breast cancer in women.

According to Dr Samuel Epstein, Professor of Occupational and Environmental Medicine at the University of Illinois in Chicago, “IGF-1 is a growth factor for human breast cells, maintaining their malignancy, progression, and invasiveness.”

Advocates of rBGH claim that increased milk production will increase the amount of food available to feed the world’s hungry.

However, introducing rBGH and advocating increases in milk production may supplant cheaper, safer, more traditional sources of food, and the resulting increase in use of animal foods will mean an overall reduction in food supplies.

Just two-fifths of a hectare can feed 20 times as many people eating a pure vegetarian diet than it can feed people eating an animal-based diet. Clearly cows are big business.

But the methods being used to boost profits could be disastrous in the long term. The BSE fiasco may just be the first of many.