Allergic reactions to this dietary ingredient may be or may become more frequent than currently recognised

Fabienne Gay-Crosier, University Hospital, Geneva

He developed breathing difficulties, a cough and other allergic symptoms four times in two years.

His symptoms appeared just minutes after eating artichoke leaves, salsify - also known as black oyster plant or viper's grass - sweets containing inulin and a margarine made with the inulin found in chicory.

"Because of its expanding use in processed foods, allergic reactions to this dietary ingredient may be or may become more frequent than currently recognised," said Fabienne Gay-Crosier and Conrad Hauser of the University Hospital in Geneva, Switzerland, and Georges Schreiber of Annemasse, France.

Health benefits

Although inulin has been used in foods for years, its popularity is increasing because of hopes that it might have health benefits, the doctors reported in a letter to the New England Journal of Medicine.

Inulin and its chemical cousin, known as oligofructose are now being added to an increasing number of industrially processed foods, such as candies, beverages, yoghurt, ice cream, chocolate, butter and breakfast cereals, they said.

It is used as a sugar and fat substitute that extends the shelf life of processed foods and can be used by diabetics.

In most countries, labelling laws require food processors to disclose if they have added inulin to a product.