Animal food allergens unmasked

New evidence has suggested that the similarity between animal food protein and human protein could indicate how much of an allergic reaction it will cause.

The similarity between food protein and human protein can be an indicator of allergenicity

The study - from the Institute of Food Research in Norwich and the Medical University of Vienna - revealed that although all proteins could become allergens, in reality the likeliness of this happening is directly related to the evolutionary distance between the animal food protein and the corresponding human protein.

Dr Clare Mills of the Institute of Food Research pointed out that this is the reason why people who are allergic to cow’s milk often can accept mare’s milk but not goat’s milk.  She said: “proteins in horse milk are up to 66% identical to human milk proteins, while known allergens from cows and goats are all less than 53% identical to corresponding human proteins. Overall we found that only an animal food protein that is less than 54% identical to a human equivalent could become allergenic.”

The group were able to classify most animal food allergens into one of three categories - tropomyosins, EF-hand proteins and caseins. Tropomyosins are proteins found in muscle tissue and given the greatest insight. In food such as shellfish study of tropomyosins showed that there was a large difference between the food protein and human equivalent.

These new findings will make it easier to recognise new allergies and will aid understanding of the mechanisms that cause an immune response.

By Leila Sattary