People with peanut allergy can react to lupin

Several hundred species of lupin exist. Lupin seed, rich in protein and fibre, has formed part of the diet of some southern European and south American countries for centuries. Many are cultivated as house plants, but these are inedible. Selective breeding has given us the sweet lupin, which tastes good and has a lower content of alkaloids than previous variants.

During recent years, the use of sweet lupin has become more widespread throughout Europe. Lupin-based ingredients improve both the nutritional value and baking qualities of food, and they are commonly added to wheaten flour. Another use is as a replacement for soya, since many consumers associate soya with gene manipulation. In addition, lupin seed is gluten-free and can therefore be safely eaten by people afflicted with coeliac disease. New studies indicate that lupin protein can have cholesterol-reducing properties.

The increased use of lupin in food has led to several reported cases of allergic reactions against lupin, including in Norway. Lupin may produce allergy either by primary sensitisation or through cross-reaction with other legumes, especially peanut. People with peanut allergy should therefore be aware that they can react to food labelled as containing lupin.

Authorities, producers and sufferers all need a reliable way of identifying even small amounts of allergens in food. For her doctorate, Lise Holden developed a quantitative and sensitive immunological method for demonstrating lupin protein. The method, the first of its kind, now forms the basis of a commercial kit developed in co-operation with an English firm, HAVen. This method was utilised in a comprehensive investigation of lupin in food for the Norwegian market in 2006 – 2007, which showed that lupin is used in many different types of food such as bread, biscuits, cakes, pasta and chocolate spreads. Even though consumers are exposed to lupin in their food, lupin allergy remains a relatively rare form of allergy in Norway today.

Holden and her colleagues have in clinical studies of children conducted provocation testing with lupin. Many of the children had lupin-specific antibody in their blood without showing clinical allergy, demonstrating just how important provocation testing is for accurate diagnosis of lupin allergy.

In addition, Lise Holden worked with the identification of specific proteins in lupin that may produce allergy. Mapping such proteins may lead to a better understanding of allergy in its entirety.

Cand. scient. Lise Holden defended her thesis for Ph. D. degree, entitled “Lupin – a new food allergen: studies on the detection, antigenicity and allergenicity of lupin proteins”, on October 17, 2008.