TCS Daily


Don't Have a Cow, Man

By Sandy Szwarc - December 29, 2003 12:00 AM

We can be assured of one thing when it comes to the safety of our food: media hysteria will be inversely proportional to actual risks.

 

Alfred Hitchcock knew a shadowy figure was far more terrifying than a well-lit known villain. Nothing haunts us more than our own imaginations, said Frank Furedi, sociologist at the University of Kent in Canterbury and author of The Culture of Fear (Continuum Publishing, 2002). Likewise today's newspapers and television networks have found that fictitious, sensationalized, "what-if?" scares of hidden dangers lurking in our foods make the juiciest stories guaranteed to capture audiences and sell papers.

 

The mania surrounding mad cow is already proving this point.

 

Since one aged dairy cow in Washington state was discovered last week to have bovine spongiform encephalopathy (BSE), or "mad cow disease," there's been an explosion of news stories panicking about the safety of our beef.

 

Cows Aren't People

 

BSE is a fatal disease in aged cows, according to the U.S. Dept of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS). Its victims are usually 3 to 6 years old -- that's old for cows, as those raised for meat are slaughtered young (under 24 months). BSE is one of several neurological degenerative diseases, like chronic wasting disease, that occur sporadically and spontaneously in wild and domesticated ruminant animals. (Non-ruminant animals such as pigs and poultry don't get the diseases).1 Scrapies, the form endemic in sheep and goats, has been identified in Europe since the mid-18th century.2

 

Despite news reports quick to place blame, scientific evidence is far from conclusive. Since BSE was first identified in 1986 on a dairy farm in England, the cause has not been pinpointed, according to the U.S. Department of Health and Human Services (HHS).

 

What is known is that BSE is not contagious and cows cannot give it to each other or other animals just by living together. Nor can they give it to people. There's never been a single case. Despite that fact, 4.5 million innocent healthy cows were destroyed in England during the peak of their mad cow hysteria, devastating beef and dairy farms and creating an environmental disaster in disposing of all those dead carcasses. (Who needs terrorists when citizens can destroy their own food system?) With hope, reason will prevail, as it has in Canada since their BSE case last May, and the unnecessary mass slaughter of healthy animals won't be repeated.

 

If other cows with BSE are discovered in North America, as they likely will, it doesn't mean safeguards have failed or that an epidemic is upon us. Unlike England's despairing bout, the few cases of BSE in Canada, Japan, Spain, Italy and scattered around the globe have remained contained and harmless.

 

England has had 90% of recorded BSE cases. Scientists believe it may have spread there because of an unusual scenario that's since been corrected, dramatically curtailing the number of cases. Learning from Britain's experience, precautions put in place elsewhere make the likelihood of a similar spread remote.3

 

Most of England's animal feed protein had been derived from bone-and-meat from ruminant animals which, it's theorized, may have caused an unnatural spread of the disease agent, possibly from scrapie-infected sheep, into feed, or that it precipitated a deformity of prions (a natural protein in brains). The risk of scrapie contamination was higher in England, with 3.4 sheep per cattle compared to 0.08 here, but is unlikely here because the U.S. has had a scrapie control program in place since 1952. Unlike England, the U.S. also always primarily used plant-based protein, such as corn and soybean, for cattle feed. Since 1997 the Food and Drug Administration (FDA) has prohibited the use of most mammalian protein in animal feeds given to all ruminants -- conventional and organic.4 The American Feed Industry Association, which represents nearly 700 feed companies, called for the complete removal of ruminant-derived meat-and-bonemeal from facilities that make cattle feed to prevent even accidental mixing of feed types, and established independent third-party certification programs to verify compliance. The National Renderers Association has followed suit.

 

As an added precaution, the U.S. has banned the importation of any ruminant animal or product from any country even suspected of being at risk for BSE, according to the U.S. HHS, FDA, Center for Food Safety and Applied Nutrition (CFSAN). No beef has been imported into the U.S. from England since 1985. A proactive, vigilant surveillance system also tests all cows older than 30 months or that appear sick or nonambulatory and removes high risk materials before processing said the National Cattlemen's Association. Some consumer groups are calling for the testing of every cow to reassure consumers. That would conservatively cost hundreds of millions of dollars, crippling the low-margin $50 billion beef industry without giving much additional safety. As Dr. Ron DeHaven, the Agriculture Department's chief veterinarian noted, the current surveillance system is designed to detect the disease if it exists in one in a million animals.

 

Human Mad Cow?

 

Cows with BSE act like animals and people with other spongiform encephalopathies -- they lose muscle control, waste away and die. Creutzfeld-Jacobs Disease (CJD), one of the human spongiform encephalopathies, occurs spontaneously in about 1 in a million people, according to the World Health Organization. It appears to have a genetic component 5 to 10% of the time, with a small percentage iatrogenic. CJD is unrelated to mad cow as evidenced by the fact it occurs in England about the same frequency as the rest of the world, reports the U.S. Centers for Disease Control (CDC) and APHIS. CJD has been around a long, long time -- long before mad cow ever hit the news, according to Konrad Eugster, MD, executive director of the Texas Veterinary Medical Diagnostic Laboratory at Texas A&M University.

 

In light of British panic over mad cow, their Spongiform Encephalopathy Advisory Committee has been closely studying and monitoring these diseases since 1990. On March 20, 1996 it noted 10 cases of human CJD that occurred in younger people and lasted longer than typically seen. Besides the fact that most variant-CJD victims had eaten beef at some time -- although no one had eaten brain tissue and one of the ten patients had been a vegetarian since 1991 -- they could find no scientific evidence linking BSE and vCJD.

 

That didn't stop vCJD from being labeled the human form of mad cow. A popular orthodoxy has evolved, fueled by media frenzy, that meat contaminated with the brain prions of mad cows could give people the disease. "It's all been much ado about nothing," said Scott C. Ratzan, director of the Emerson College/Tufts University School of Medicine Program in Health Communications and editor of the Journal of Health Communications. "Based on available scientific evidence, we can be virtually certain that mad cow disease poses no threat to humans."

 

While several studies published in Nature reported an association between vCJD and BSE, they are far from conclusive and other researchers question the theory. No one has ever been able to establish that any vCJD victim has ever eaten beef from a diseased animal or that infected prions can cross the species barrier and cause disease in humans. There also aren't increased cases in cultures where brains are a favorite dish. Transmission from other exposures doesn't hold up, either, as there's no higher incidence among farmers, slaughterhouse workers, butchers or others in greater contact with BSE or animal products.

 

Rather than being some exotic new prion disease Alan Ebringer, a professor of immunology at King's College, London believes vCJD is the result of the body's own immune response to a bacteria called Acinetobacter, making it another autoimmune disease with mechanisms already well-understood by science. George A. Venter, a public health consultant from Hamilton, Scotland, noted in an October issue of the British Medical Journal. that the evidence linking BSE and vCJD is weak. Even when mice with the human prion protein were injected with BSE prions, they didn't get the disease, Venter found. The first case of CJD, diagnosed in the 1920s, was in a 23 year old person, casting doubt that vCJD is a new disease in younger people at all. Clinical features, spread and pathology of vCJD are more similar to Kuru, a disease found in Papua New Guinea, he found. Venter also noted that cases are much rarer than would be expected from a food source.

 

What are our chances of contracting vCJD?

 

Regardless of the cause, since first identified in the 1980s CSFAN reports that as of May 2003 there have been in total approximately 139 cases of vCJD worldwide, with only 1 case in 2000. Diarrhea diseases, in contrast, cause 2.2 million deaths every year.

 

Those fretting about mad cow probably think nothing of taking a bath (which kills 320 Americans a year), walking downstairs (which kills 1,421 Americans annually) or driving their car (which kills 42,000 of us each year). Our odds of getting vCJD from eating British beef, said the CDC, is about one in ten billion.

 

By comparison, NASA's Near-Earth Object Search Report determines there's a 1 in 400,000 chance of a major asteroid striking the earth. That translates to 99.99975% chance an asteroid will miss the Earth but doesn't stop some from fearing Armageddon.

 

If it's biologically implausible for humans to get mad cow from beef, why the alarm? "Because you don't let the facts get in the way of a good story," said Venter. "The mad cow disease story would be a non-story in the U.S. if it were not for the propaganda efforts of vegetarian groups," said the National Council Against Health Fraud. "EarthSave, PETA, PCRM, and the Seventh-day Adventist website have seized upon the opportunity to frighten people into behaving in ways they find ideologically delightful."

 

The Center for Science in the Public Interest (CSPI), renowned for its food fears, warned in a Nutrition Action Healthletter article "What Could Happen Here?" that "vCJD spares no one" and that the connection between it and mad cow prions is "spreading fear and panic across the globe." In a Dec. 24th New York Times article Caroline Smith DeWaal, CSPI's director of food safety, wasted no time telling consumers they should avoid eating any ground meat -- or pizza, tacos, hot dogs, salami, bologna and other foods that could contain ground meat -- or even T-bones that could have been cut from close to the spinal column. They neglected to report that no infective agent or prion has ever been found in muscle tissue (meat) or milk, and that the brain and spinal column of the infected cow had been removed and sent to the USDA's National Veterinary Services Laboratories in Ames, Iowa.

 

But what if every fear being theorized by the fear mongers became a reality? To find out, the USDA commissioned a study by the Harvard Center for Risk Analysis to study worst case scenarios. Their report found that should BSE be introduced in the U.S., measures taken during the last five years by the government and industry, while not foolproof, will arrest and eradicate the disease. The risk isn't zero, said David Ropeik, director of risk communication, "but it's as close to zero as you can get."

 

Endnotes

 

1. Gegner, LaNce, Deer Farming, Appropriate Technology Transfer for Rural Areas, Rural Business-Cooperative Service, US Dept of Agriculture; May 2001, 1-23.

 

2. US. Center for Disease Control, BSE and vCJD: Background, Evolution, and Current Concerns; Emerging Infectious Diseases; Jan-Feb 2001; 7(1). http://www.cdc.gov/ncidod/EID/vol7no1/brown.htm

 

3. Meister, K, Kava, R, Whelan, E, The Role of Beef in the American Diet (American Council on Science and Health, January 2003) http://www.acsh.org/publications/reports/beef2003.pdf

 

4. Tan, Williams, Khan, Champion, Nielsen; American Medical Association Council on Scientific Affairs, Risk of Transmission of BSE to Humans in the United States, JAMA, 1999; 281: 2330-30.

 

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