E-Mail This Article to a Friend MAD COW An alternative theory of what causes it BY DAN KENNEDY

What if everything we know about mad-cow disease is wrong? What if eating contaminated meat from cattle infected with bovine spongiform encephalopathy (BSE) does not cause new-variant Creutzfeldt-Jakob disease (nvCJD), as the conventional scientific wisdom would have it? What if — instead — cows get BSE and people get nvCJD because of environmental factors?

Two years ago, I identified mad-cow disease as a potentially important undercovered story, and urged the media to look into it more deeply (see "Don’t Quote Me," News and Features, December 28, 2001). It didn’t happen, of course — until last week, when it was reported that a cow with BSE had been discovered in Washington State.

At that point I heard from Jason Clarke, who writes a weblog called BiggerBoat.net. Clarke saw an item I posted on Media Log, at BostonPhoenix.com, and urged me to learn more about an angle I’d never heard of before.

According to most scientists, mad-cow disease spreads by feeding them ground-up cattle parts. Especially dangerous is nervous-system tissue — the brain, the spinal cord, and the like. If a person eats beef from an animal with BSE, the scientific name for mad cow, she or he may contract nvCJD, which is fatal.

But according to the alternative theory, the real cause of both BSE and nvCJD is some hazy combination of too much manganese and aluminum in the environment, not enough copper, even too much exposure to ultraviolet light. Any or all of these factors can damage prions, proteins that protect the brain from toxic substances, and thus unleash various types of spongiform encephalopathies — not just BSE and nvCJD, but also scrapie in sheep and chronic wasting disease in deer and elk.

These factors may have come together in a particularly nasty way some 20 years ago, when the British government ordered cattle farmers to use an insecticide to kill off a pest known as the warble fly. The insecticide may have caused a copper deficiency in the animals, leading eventually to the world’s worst outbreak of mad-cow disease.

The principal proponent of this theory is an amateur scientist and farmer named Mark Purdey, who lives in Britain and who has attracted at least some support from both Prince Charles and David Brown, a respected scientist at Cambridge University who is an expert on CJD. Purdey was the subject of an extensive profile in London’s Evening Standard in December 2000, but he is virtually unknown in the United States.

To be sure, Purdey’s theory is somewhat far-fetched. Ten years ago, there were scientists who believed that HIV did not cause AIDS. Then protease inhibitors came along, removing all doubt about the connection.

But the cause of brain diseases such as BSE and nvCJD, and their relationships to one another, remains poorly understood. At the very least, government regulators, the scientific community, and the media ought to keep an open mind even as they seek more traditional answers.

Mark Purdey’s Web site is at www.markpurdey.com. For more information on how environmental factors might cause BSE and nvCJD, go to www.mercola.com/2000/dec/17/bovine_spongiform_disease.htm .