There is virtually no evidence that eating meat from cattle with mad-cow disease can cause a similar condition in humans, a Scottish researcher says.

As a result, George Venters, a consultant in public-health medicine, is openly questioning the need to ban British beef and to limit blood donations, saying the moves were based on precipitate and false conclusions.

Writing in today's edition of the British Medical Journal, Dr. Venters says the theory that people could contract new variant Creutzfeldt-Jakob disease was highly speculative when it was put forward in 1996, at the height of the mad-cow scare.

While public-safety concerns justified the initial reactions, the theory has not stood the tests of time and scientific examination, he writes.

"What was initially a speculation has evolved into orthodoxy among the medical profession," Dr. Venters argues.

This has occurred despite mounting evidence that there is no cause and effect between eating beef and developing the rare neurological condition, he writes.

Concern about the possible spread of the disease prompted Canada to restrict blood donations from anyone who has lived or travelled in the United Kingdom or France for a total of three months between 1980 and 1996.

Jirina Vlk, speaking for Canadian Blood Services, said the agency would not comment directly on the BMJ article, but "we continue to monitor international developments and research in consultation with Health Canada."

Dr. Venters believes that the infectious agent that causes bovine spongiform encephalopathy cannot infect humans and that, even if it could, contracting the disease from food would be virtually impossible.

Further, the researcher argues that "new variant" CJD may not even be a new form of the disease. While he does not question the number of newly diagnosed cases of the grave neurological disease in Britain, he attributes the rise to increased vigilance. Dr. Venters labels the mad-cow scare in humans the "epidemic that never was."

To date, there have been 106 nvCJD deaths in the United Kingdom, three in France and one in Ireland. There have been no cases in Canada or the United States, or in any other country where BSE has been detected.

Many scientists believe nvCJD can be contracted by those who eat meat that contains part of the brain or nerve system of infected cattle.

Dr. Venters, who works at the Lankarshire Health Board in Hamilton, Scotland, said that instead of merely accepting that notion, scientists need to rigorously apply the criteria that epidemiologists use to determine what has caused an outbreak of disease.

They include:

Biological probability: Dr. Venters writes that there is no evidence that the prion, a rogue protein, that causes BSE in cattle can infect humans, and much evidence of a protective species barrier. Attempts to infect mice with human genes with BSE have failed.

Consistency of findings: While the general public consumed beef, nvCJD has been diagnosed almost exclusively among the young. This suggests it is not an infectious disease, and that it is actually Creutzfeldt disease, which was identified 80 years ago.

Pattern of infection: All food-borne epidemics follow a similar pattern, beginning with a small number of cases and rapidly rising to a peak. Cases of nvCJD have been identified steadily and slowly since 1994, meaning it does not follow the pattern.

Quality of evidence: Dr. Venters writes that the evidence linking nvCJD to tainted meat is, at best, poor. He complains that "evidence that has been amassed is directed toward confirming the hypothesis rather than testing it. Salient contrary information has been either played down or ignored."

Dr. Venters argues that well-meaning scientists and public-health officials have fallen victim to the "faggot fallacy," a belief that multiple pieces of suspect or weak evidence provide strong evidence when bundled together.

BSE was first detected in England in 1985 among cattle that had consumed feed that contained parts of sheep that died of scrapie. Since then, millions of cows have been destroyed across Europe as a preventive measure.

All these related diseases -- scrapie, BSE and nvCJD -- are caused by prions. There is much debate about whether prions are infectious in the traditional sense. Scientists don't even know whether the disease can be transmitted by blood.