Fewer Britons may have the human form of mad cow disease than previously thought, a new study suggests.

It's not known how many people might have eaten infected meat and carry the abnormal prions that cause both BSE (bovine spongiform encephalopathy or mad cow disease) and its human equivalent, known as Creutzfeldt-Jakob disease (CJD).

Since 1995, there have been 168 definite or probable cases of the fatal, brain-wasting disease among people in Britain, according to the country's Health Protection Agency.

Based on those numbers, scientists estimated another 10 to 190 cases of variant CJD, one of two types of the disease, to appear over the next ten years.

But in this week's issue of the British Medical Journal, researchers suggest that the actual prevalence of the disease in the British population might be much lower.