Mad cow disease and U.S. meat regulations

Sound Consumer | April 2001

by Kathy Blackman, PCC Board Administrator

[This article is compiled from the following source materials:
U.S. Food and Drug Administration, U.S. Department of Agriculture, Journal of the American Medical Association, Rachel's Environmental and Health Weekly, American Journal of Epidemiology, National Institutes of Health, Center for Disease Control]

We've seen the news reports about mad cow disease in Europe. We've also heard government and industry assurances that it can't happen in this country.

Numerous scientific studies and other public documents, however, point to a different conclusion. The available information suggests that a form of mad cow disease can happen in the United States and may be here already. PCC Natural Markets believes it's important to share this information with consumers.

The background
Mad cow disease, or bovine spongiform encephalopathy (BSE), is one of several diseases of the nervous system that can affect animals, including humans, and can cross species barriers. Regardless of species, all of the transmissible spongiform encephalopathies (TSEs) share several characteristics:

  • changes in the brain's physical structure
  • behavioral changes, including disorientation and loss of balance
  • rapid progress once symptoms appear
  • inevitable death

Several TSEs are known in humans; the most common is known as Creutzfeld-Jakob Disease (CJD). People are known to develop CJD through several different paths: spontaneous genetic mutation, inheritance of a defective gene, transplant of nerve tissue or blood transfusion from a diseased donor, and ingestion of animal tissue (particularly nervous system tissue) from a diseased animal.

In each case, the disease is believed to be caused by prions, proteins that are normally produced in animals by a gene called the PrP gene. Differences in the sequence of abnormal prions cause the prions to fold on themselves in unusual ways. Whether produced by the defective gene or introduced to the body by a contaminated source, these abnormal prions cause damage to neurological and other tissues, producing the characteristics listed above.

In Britain, the mad cow disease epidemic of recent years is the result of feeding cows a feed mixture containing by-products from diseased cows and sheep. This practice was banned in Britain since 1988, but not before the disease already was transmitted to people who consumed beef from the BSE-infected cows. The form of CJD traced to British beef is known as new variant CJD (nvCJD), because the symptoms, age of onset, and physical changes in the brain vary somewhat from those of CJD caused by genetics, transplants or transfusions.

The regulators
The U.S. Department of Agriculture (USDA) stakes its claims that mad cow disease has not been found in this country — and that no people here have contracted CJD from diseased meat — on this variance. The numerous studies, however, done here and in other countries to determine the likelihood and methods of transmission of TSEs among species, shows the ability of the disease to transform itself both in terms of symptoms and aggressiveness. This means it's conceivable that American strains of BSE and CJD already exist, but have not been traced as such.

USDA also claims that existing animal feed and import regulations safeguard the food supply, and that the chance of a similar pandemic of either mad cow disease or its transmission to humans in the United States is quite small. The safeguards are not altogether reassuring for a number of reasons.

The Food and Drug Administration (FDA) regulates animal feed under the Food, Drug and Cosmetic Law.

  • Only since 1997 has the FDA had a rule that prohibits the feeding of certain animal by-products to animals raised for human consumption.
  • The rule only prohibits the use of ruminants (sheep, cows, goats, deer, and elk) and mink in feed intended for ruminants. Ruminant blood and gelatin, and by-products from chicken and pork, still may be fed to ruminants.
  • Animal feed for chickens, hogs and pets is not restricted.
  • Evidence of TSEs in this country has been found in mink, cats, elk and deer as well as in sheep and goats.

In contrast, Britain's rule has prohibited the addition of any animal by-products to any animal feed since 1988.

While FDA's goal is 100 percent inspection of rendering plants and feed mills to determine if products are labeled to avoid mix-ups, to date the inspections have not been completed. Among completed inspections of rendering plants and feed mills, approximately 20 percent of FDA-licensed facilities are out of compliance with labeling requirements.

Even labeling does not guarantee against mix-ups, evident from the incident at a Texas feed mill, where cattle meat and bone meal inadvertently were added to cattle feed.

USDA regulates imports of animals and animal products into this country. Since 1989, USDA has banned the import of live ruminants and most animal by-products made from ruminants imported from countries where BSE is reported, but only since 1997 for all of Europe. Symptoms of BSE appeared in British beef prior to 1989. Since it takes two to eight years for symptoms to appear in livestock, it's possible that BSE-affected animals and by-products entered the country before the USDA ban took effect. In December 2000, USDA issued an emergency ban on all rendered animal by-products from Europe, regardless of species, due to the discovery of potential cross-contamination with BSE.

Also, beef cattle are generally slaughtered in this country between one-and-a-half and two years of age, so they wouldn't necessarily show symptoms of BSE prior to slaughter. Dairy cattle might, since they're kept in production longer. Particularly worrisome is the unknown potential for hogs to succumb to TSEs. Hogs displaying neurological symptoms were observed by a USDA inspector at a slaughterhouse in Albany, New York, for more than a year beginning in 1979.

When tissue samples taken from brains of these Albany hogs were examined, one sample showed the spongiform damage diagnostic of TSEs. Forty percent of the samples showed changes in the brain tissue that might indicate early TSE. However, USDA has done no further studies to follow up on the possibility of TSEs in hogs. Since hogs are slaughtered around five months of age, well before symptoms are likely to be observable, it's possible that a form of TSE exists undetected in the pig population in this country, making its way into animal feed and the human food supply. The extent of the risk is unknown.

The Center for Disease Control, an agency of the National Institutes of Health, has been keeping mortality figures for CJD. A study published in the Journal of the American Medical Association, analyzed the figures from 1979 to 1998; both the death rate and the absolute number of deaths attributed to CJD show a slight but consistent increase over that period of time.

Lastly, at least two separate studies of brain tissue from people whose cause of death was listed as Alzheimer's Disease found that a significant portion — 5.5 percent in one case and 13 percent in the other — actually died of CJD. The latter study was performed by Dr. Laura Manuelidis, Head of Neuropathology at Yale University's Medical School, in 1989. Dr. Manuelidis states that because CJD-like diseases can only be definitively diagnosed by brain biopsy after death, they may be underreported.

Given CJD's nature and that scientists still are unraveling its mysteries, consumers have reason to be uneasy and to be asking questions. Like Foot and Mouth, E-coli, and salmonella, mad cow disease and its variants are more than coincidence. It's a man-made problem that underscores why consumers have demanded natural foods and organic standards.

What can consumers do?
Long before mad cow disease made headlines, the careful animal husbandry practices by PCC's meat vendors afforded a high level of consumer confidence. PCC Natural Markets advocates the right to be an informed consumer.

  • Know where your meat comes from. Rely on vendors such as Oregon Country Beef, Beeler's and Sara Joe's Pork, Umpqua Valley Lamb, Diestel's Turkey, Applegate Farms deli meats, Ranger, Rocky Junior, and Rosie's Organic Chicken who have provided assurances that the feed used for their livestock is free of all animal by-products.
  • Avoid altogether dietary supplements containing animal glandular tissue, pituitary or other nervous tissue.
  • Stick to supplements using vegetarian gelatin capsules, such as those at PCC.
  • Be aware that manure (including chicken manure), bone meal, and blood meal are all substances in which prions can be found. If you use these substances on your garden, wear gloves, and a mask to avoid inhaling the dust.
  • Educate yourself and others about food regulations.
  • Support efforts to close the regulatory loopholes.

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