High vCJD rates in Scotland could be due to poor diet

The rate of contracting variant Creutzfeldt-Jakob disease (vCJD) has been found to be twice as high in Scotland and the north of England as elsewhere in Britain, leading to speculation that poorer diets in these areas may be responsible for the increased risk.

Professor James Ironside, the senior pathologist at the National CJD Surveillance Unit in Edinburgh, said that the more frequent consumption of cheap meat products such as pies and burgers in the north of Britain may explain the difference. These products were more likely to contain mechanically recovered meat that had been sluiced or scraped off the bones of cattle before such material was banned for human consumption. This type of meat carried the greatest risk of infection with bovine spongiform encephalopathy (BSE).

So far, 102 people have died from vCJD in the United Kingdom, three in France, and one in the Republic of Ireland. Professor Ironside, speaking at the British Association's Festival of Science meeting in Glasgow, also said that the number of cases in the United Kingdom is showing a steady upward trend. From 1996 to 1999 the annual number of cases of vCJD was about 14, but last year this increased to 28, and there have been a further 17 so far this year.

Professor Ironside said that the previous worst case scenario of 140000 deaths from vCJD in the United Kingdom may have to be revised upwards if this continues. An analysis of the UK figures has also shown a north-south split, with an incidence of 2.71 per million people in Scotland and the north of England, compared with 1.47 in the south of England and Wales.

Most of the meat products infected with BSE entered the food chain in the late 1980s and early 1990s, but Professor Ironside said that efforts to establish whether diet is responsible had been hindered by the food industry.

“Our investigations have not been helped by the reluctance of the food industry to give us the information about what kind of meat went into their products,” he said. The Food Standards Agency is now involved in trying to obtain such information.

The other possible explanation for the higher concentration of cases in the northern half of Britain is that people in these areas have a greater genetic susceptibility. The surveillance unit has found that every person who has contracted vCJD shares a common genetic factor that is present in about a third of the population.