Report on the dairy industry

...Crohn’s disease currently presents the industry with its greatest challenge. Can it be caught from infected milk products? So far, all evidence is circumstantial and by no means conclusive but, says Dr Eric Hillerton of the Institute for Animal Health, the potential risk to people has to be taken seriously.

Crohn's wrecks lives with chronic abdominal pain, diarrhoea and fatigue, sometimes it is fatal. GP records suggest that, in the UK, more than one person in 700 may be suffering from Crohn’s and the numbers appear to be on the increase.

Crohn’s disease is suspiciously similar to a disease of cattle and other ruminant animals, a chronic and potentially fatal inflammation of the digestive tract known as Johne’s disease. The organism responsible is Mycobacterium avium paratuberculosis (MAP). Worldwide it is a very common problem and has been reported on around 1% of dairy farms in southwest England. Only a low proportion of the animals on these farms - about 2% - show clinical symptoms but both they and apparently healthy animals in these herds are likely to carry infection by MAP.

A link between MAP from milk sources and Crohn’s disease was first postulated in 1913. It remains tentative but the Advisory Committee on the Microbiological Safety of Food (ACMSF), which advises the Food Standards Agency, has accumulated research suggesting that about 2% of the UK’s retail milk may contain detectable numbers of the MAP organism.

One of several experts who believe that MAP causes Crohn’s is Professor John Hermon-Taylor of St George’s Hospital in London: “Our own labs have shown unequivocally that MAP is present in the inflamed gut of the overwhelming majority of people with Crohn's Disease and rarely in people not showing signs of the disease”. His team has reported successfully treating a child suffering from Crohn’s with drugs which act against MAP.

Understandably, this research has rattled the dairy industry. With market share shrinking and margins low, there is little incentive for individual producers to step out of line with expensive measures to eliminate MAP entirely. Only regulation could level the competitive playing field. As a first step, the Food Standards Agency has recommended an increase in pasteurisation times (from 15 to 25 seconds at 72°C). All the UK’s major dairies have voluntarily adopted the new standard, although its impact on the number of MAP cells in milk remains uncertain...

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