People with a peanut allergy should avoid all products containing lupin flour

A report in this week’s issue of The Lancet concludes that adults and children with an allergy to peanuts could also be allergic to lupin flour—a substance that is used in some European countries as a potential replacement for soya flour.

Food manufacturers in these countries are using it in certain specialty breads, bakery goods and catering foods, and a small number of these are finding their way into the UK. The authors suggest that people with a peanut allergy should avoid all products containing lupin flour until they can be specifically tested to see if they are susceptible.

The report details the case of a 25-year-old woman who, in August 2004, had an allergic reaction after eating a restaurant meal of chicken, French-fried potato, and onion rings. The woman knew she had a severe allergy to peanuts after a reaction to a peanut sweet when she was 15. However, peanut contamination of her food was considered unlikely. Lupin flour, an ingredient of the onion ring batter, was eventually identified as the cause of her attack.

The authors note that the prevalence of lupin allergy has increased markedly in some countries, especially France, where in 1997 the addition of lupin flour was first permitted to wheat flour. Although the food use of lupin has been permitted in the UK since 1996, few lupin-containing foods are so far on sale; the main source appears to be imported bakery and catering goods. A new directive on food labelling came into force in Europe in November 2004, requiring food manufacturers to specifically list 12 potential allergic ingredients. Lupin flour is not included on this list despite recommendation from the UK based Institute of Food Science and Technology.

Author Dr Michael Radcliffe (Royal Free Hospital, London, UK) states: “Further work will be required to establish the prevalence and significance of lupin allergy. Meanwhile those with peanut allergy, around 1% of the UK population including 250 000 pre-school children, appear to be at particular risk as up to half may be pre-sensitised. They should be advised to avoid all products containing lupin until they can be specifically tested.”