Mad-Cow Madness: What We Now Know about Mad-Cow Disease Shows the Folly of Excessive Precaution

When Oprah Winfrey stated on her show in 1996 that she'd never eat another hamburger, she was reacting to the remarks of Humane Society representative and former cattle rancher Howard Lyman, who said that “mad-cow disease” could infect “thousands of people” and agreed that it “could make AIDS look like the common cold.” As recently as November 2001, a leading researcher into the human toll of the disease estimated that somewhere near 100,000 people would die in <?xml:namespace prefix = st1 ns = “urn:schemas-microsoft-com:office:smarttags” />Britain as a result of eating infected meat. The same researcher has just quietly released his latest estimates of the future death toll: The best estimate is 40 more deaths. <?xml:namespace prefix = o ns = “urn:schemas-microsoft-com:office:office” />

The whole Mad Cow crisis in Britain reveals the folly of precipitate and precautionary action. The background to the crisis is well known in the U.K., but perhaps less so over here. In the mid-late '80s cows, were fed meals that included other cow remains (like ground up bone). It appears that this feeding method helped transmit Bovine Spongiform Encephalopathy a disease that progressively destroyed brain functions in cows. When symptoms first became apparent, infected animals appeared to be behaving erratically, hence “mad-cow disease” caught on in the popular imagination.

A lot of meat from infected cows entered the human food chain. Cheap meat especially often contained brain and spinal-cord tissue. Initially, scientists believed that BSE and diseases like it could not pass the species barrier and infect other species, so the humans who had eaten the cheap meat—like impoverished Oxford students of the time such as me—were safe. Then some people started dying horribly of a human spongiform encephalopathy, similar to an already known ailment called Creuzfedlt-Jakob Disease (CJD). Doctors eventually decided this was a variant of the existing disease because it had slightly different characteristics, and so it became known as vCJD. The method of transmission of this disease is still unknown.

In the early 90s, scientists decided that they did not have enough evidence to be as sure as they could be that beef was safe. Stephen Dorrell, as health secretary, therefore announced this to the nation. The reaction was worse than even the Ministry of Agriculture (MAFF) expected. Public confidence in British beef was shattered, and sales plummeted, despite the fact that the practice of feeding cows remains of other cows had ceased. Domestic beef disappeared from the menus of restaurants, cafes, and sandwich shops. Drastic action was decided on to restore public confidence and a program of mass slaughter began aimed at eliminating BSE from the national herd. This cost the government billions. As a colleague of mine, from when I worked for the British government on rail privatization, commented: “We privatized electricity to finance tax cuts. We're privatizing the railways to pay for a barbecue.”

But the economic disaster was not the only negative consequence. Public confidence in government scientists was shattered too. Once the possibility of transmissible vCJD had been established, the modelers got to work. If anyone who had eaten brain-related tissue in the '80s was at risk of exposure, then potentially millions could have been exposed to a horrible brain-eating disease for which there was—and still is—no cure. Unsurprisingly, this made headlines. The basic line of thinking among the public was: “They told us we were safe, now they say we're all going to die in agony. How could they be so wrong? They're either incompetent or evil.” This attitude is at the root of current British Luddism about GM foods, among other things.

Yet those apocalyptic models all depended on the incubation period of the disease. The shorter the incubation period, the more people would die. As time dragged on, however, and the exponential upturn in vCJD cases never materialized, the models got more conservative. Now it looks as if they were just plain wrong. The disease actually appears to affect only people with certain genetic characteristics, which limits susceptibility to only 40 percent of the British population to begin with. There has also been a decline in the number of new cases arising over the past two years, strongly suggesting that the incubation period was about 12 years, and that most people who were infected have already developed the disease.

Britain, therefore, almost destroyed an industry, spent billions, and crippled the reputation of science as an honest profession for the sake of precipitate action against a disease that killed a handful every year. The Mad Cow crisis is a case study in how governments believing the worst as a matter of course and taking action before the full facts are ascertained can bring untold costs to a nation. The similarities to the panicked approach to global climate change should be obvious: In both cases, the science is debatable, the doom-mongers have the loudest voices, and governments have decided on action which will definitely cost billions but which may well not produce any concrete results, to say nothing of the unintended consequences.

Just on Tuesday, a Canadian cow was found infected with BSE. It has been dealt with by removing it from the food chain. Canada has had one previous case—in 1993—and it is not yet clear whether the animal was Canadian in origin or imported. Sensible precautionary measures have been put in place to prevent any spread of the disease; and Secretary of Agriculture Ann Veneman, in imposing temporary bans on importation of Canadian ruminants, was careful to say that, “risk to human health and the possibility of transmission to animals in the United States is very low.” The reaction seems appropriate to the danger up to now, a far cry from what happened in Britain.

Doom mongers often talk about the precautionary principle—the idea that you should not adopt any new technology unless you are certain it is safe. It might be better for their credibility if they adopted some precaution before predicting that the latest cause celébre could kill more people than AIDS.