People who are allergic to foods such as milk, nuts or cereals may one day be able to eat them without any adverse affects.

Scientists at the University of California have found a way to treat foodstuffs so they no longer trigger allergic reactions.

Bob Buchanan, Professor of Plant Biology at the University of California at Berkeley, has discovered that a protein called thioredoxin can prevent foods causing allergies if it is present in high concentrations. The protein is a complex chemical found naturally in many plants,

Thioredoxin can prevent allergies by breaking down strong double bonds between sulphur atoms in proteins in the plant material. These disulphide bonds, commonly found holding protein molecules together, seem to be the most important cause of allergies in milk and some nuts and cereals.

Professor Buchanan has used thioredoxin's ability to break disulphide bonds to treat food to prevent allergies.

"What we do is to take advantage of thioredoxin's ability in food treatment to eliminate disulphide bonds," explained Prof Buchanan.

"And when they are eliminated we see two consequences. One is that the proteins are changed so the immune systems of the animals we are using for tests no longer recognise the allergens, the parts of the proteins that cause allergic reactions. The other thing it does is to make the proteins very digestible."

Disulphide bonds seem to be the main cause of allergy to milk

In tests on animals the protein has been shown to work on cereals, milk and soya protein. Nine out of ten dogs with known allergies to cereals showed no allergic reaction at all when fed with wheat protein treated with thioredoxin.

Allergen-free pet food is expected to be on the market soon. Human food is expected to follow.

Professor Buchanan said he was discussing a project with a European firm to produce an infant formula food, "because allergy is most prevalent in infants."

According to the professor, in Japan one in three children has an allergy. In the USA the figure is about one in six, and there is a similar number in Europe. "I would think in three years we can be thinking of human clinical trials," he said.

Bob Buchanan is also working to insert extra genes for thioredoxin into plants so they will be naturally pre-treated to prevent their causing allergies.