Lewis Wolpert: 'Doctors could play an important role in food irradiation'

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Certain words from science have a negative effect. "Clone" is a good example. But worse is "radiation", which is associated with all sorts of evils, particularly nuclear power.

Certain words from science have a negative effect. "Clone" is a good example. But worse is "radiation", which is associated with all sorts of evils, particularly nuclear power. This may account for the neglect of using irradiation to reduce food poisoning.

In the United States, it is estimated that there are 76 million cases of food-borne disease every year, leading to thousands of people needing hospital treatment and some 5,000 deaths.

Each year, it is estimated that up to 5.5 million people in the UK may suffer from food-borne illnesses - that's one in 10 people. Food-borne bugs in meat and poultry are major causes. Yet the irradiation of food has the potential to reduce dramatically the dangers of food poisoning.

Food irradiation is basically the same as pasteurisation of milk by heat, which can destroy nasty micro-organisms without affecting the nature of the milk. Yet there is resistance to food irradiation. Few people are aware that radiation is used to sterilise many of the products used in their homes. These include baby-bottle nipples, cosmetics and bandages.

Research on methods to control food-borne bacteria go back a long way. In 1904, there was an article in the journal Proceedings of the Royal Society showing that radiation from radium inactivated Staphylococcus (a parasitic bacterium that can cause boils and blood poisoning), as well as the bacteria that cause cholera and anthrax.

In 1905, a patent was issued to British merchant J Appleby for the use of radiation to improve the condition of foodstuffs. But it is only since the 1950s that the technology for commercial application has become available.

There are various arguments against the irradiation of food. One is that irradiation produces a chemical in the food that could cause cancer, even though it is present in tiny amounts. All the evidence is against this. No evidence of any negative effects were observed in studies in which animals were fed irradiated food as about half of their normal diet. Another argument is that irradiation destroys the nutritional quality of the food. But the main constituents of food, such as proteins, carbohydrates and fat, are not appreciably affected at the doses used. Both the US Food and Drug Administration and the American Dietetic Association concluded that irradiation poses no risk to any nutrient in food.

There is the claim that irradiation is a quick fix for a major problem regarding food hygiene. It is seen as an easy way for the food industry to ignore sanitation before irradiation. But even good sanitation can result in less than 1 per cent of meat from a slaughterhouse being contaminated, and in the US this would mean that some 11 million kilograms of meat are contaminated. Irradiation could prevent this. But a major aspect of resistance to its use is its association with radioactivity, and the beliefs of certain groups about interfering with nature.

Irradiation does have its problems, as it does not prevent subsequent contamination by consumers or food-service workers. There is evidence that irradiation can affect the odour, colour and texture of some foods. Also, some fruits, vegetables and dairy products have a reduced shelf-life after irradiation.

In the US, only 10 per cent of herbs and spices are irradiated and less than 0.002 per cent of other foods. In the UK, there are strict regulations about food irradiation: it is not legal for any foods, apart from herbs and spices, to be irradiated for general sale, as no company holds a licence to do so.

It may rest with the public to encourage more use of food irradiation. There was a related situation in the 1930s, when pasteurised milk was introduced. Doctors and others in the health field played an important role in getting it accepted. They could play a similar role in relation to the irradiation of food. This will not be easy. In the US, approval has been given for the irradiation of hamburgers for school lunches. But groups opposed to irradiation are claiming that the children are being used as experimental animals.

Lewis Wolpert is professor of biology as applied to medicine at University College London