Why mad cow could happen in America: the U.S. government might not be doing all it can to prevent an outbreak of mad cow disease. Here's a look at the risk factors—and what you can do to minimize them

Natural Health, Oct-Nov, 2001 by Martiga Lohn

THE THREAT OF MAD COW DISEASE has plagued Britain for more than a decade. But on our shores, we have nothing to worry about--at least that's what U.S. government officials maintain. Consumer advocates and watchdog groups say this official line is naive and dangerous: Public health officials have been wrong before about how deadly and widespread diseases can be (think of AIDS, they say), and the government has been guilty of moving too slowly or protecting business more than people.

"We don't want to send people into a panic," says Michael Hansen, Ph.D., a biologist and research associate for Consumers Union in Yonkers, N.Y. "But the bottom line is that we don't know what the real risk is." What we do know, he says, is that this is a lethal disease, that the agent that causes mad cow can't be destroyed easily, and that the symptoms of the disease (in both cattle and people) can't be detected until shortly before death.

U.S. regulatory agencies and the beef industry claim that a high fence separates American consumers and cattle from the dangers in Europe. But there may be gaps in this fence.

History: THE BRITISH EXPERIENCE

Those protective fences were built because of what happened in Britain. The experience there also illustrates the dangers of ignoring gaps. When British cattle became sick in large numbers in the 1980s, the British government reassured the public that there was no danger to humans. Consumers continued to eat beef, even as news reports showed cattle drooling, stumbling, acting aggressively, and eventually dying. Farmers and scientists began calling this collection of symptoms mad cow disease, and autopsies revealed that the cows' brains resembled the brains of people afflicted with a rare, fatal human disease called Creutzfeldt-Jakob disease (CJD). CJD usually strikes people in their 50s or older, causing them to lose control of the most basic functions. But in the mid-1990s, several British teenagers and young adults began showing those symptoms. Researchers began to suspect a new, virulent variant of CJD and theorized that it could be related to the victims' diets.

When the British health minister admitted in 1996 that the probable cause of vCJD (as the new variant is called) was beef infected with mad cow, sales of British beef took a nose dive around the world. Some epidemiologists believe the problem started when cattle were fed the ground remains of sheep infected with scrapie, a disease similar to mad cow, as well as the ground remains of cows that were already infected. (Researchers aren't sure why mad cow emerged when it did; some link it to the increased use of animal protein in animal feed.) In the 1990s, the disease spread to cattle in other European countries, in part because Britain continued to export infected animal feed until 1996.

Transmissible spongiform encephalopathies (TSEs)--including mad cow disease, scrapie in sheep, and CJD in humans--are thought to occur when proteins called prions fold into abnormal shapes. Normal prions are harmless, but researchers theorize that deformed prions induce other prions to mimic them, and they concentrate in the central nervous system, causing spongelike holes in the brain.

Most researchers believe humans get vCJD by ingesting parts of cattle that contain infectious prions, including the brain, spinal cord, gut, and bone marrow. (Milk products are generally considered safe.)

But we don't understand as much about the disease as reassuring government officials would like us to think. Prions are a serious foe: They can withstand high temperatures, freezing, sterilization, and radiation, so no one has figured out a practical way to destroy them. Similarly, researchers don't know how many prions you need to ingest to be infected, or how long the disease incubates in humans before symptoms appear. Even the idea that the disease is spread by eating infected animal parts is now in question; a new theory has sparked controversy in Britain. (See "Is There a Pesticide-Mad Cow Link?" page 130.)

Despite these serious questions, John Stauber, co-author of Mad Cow U.S.A. (Common Courage Press, 1997) and founder of the nonprofit Center for Media and Democracy in Madison, Wis., worries that the U.S. government may be more concerned about selling beef than protecting consumers. After all, the British experience taught us how completely mad cow can destroy the demand for beef. "The U.S. is the largest meat exporter in the world," he says. "As long as it can claim there is no mad cow disease here, it's going to be a tremendous economic advantage for the U.S. meat industry. If you have a choice between buying hamburger meat from the U.S. or France or Britain or Germany and your concern is mad cow disease--no pun intended--it's a no-brainer."

In America: HOW MAD COW COULD AFFECT US

Consumer advocates and watchdog groups believe it's only a matter of time before mad cow disease emerges in this country. Some say it's already here, but has yet to be detected. Because it has an incubation period of two to eight years in cattle and an unknown period in humans, it could still be invisible.