Every spring, millions of people begin to suffer: bouts of sneezing, a blocked nose and itchy, watery eyes herald the start of the birch pollen season. Around 50 to 70 per cent of those affected also struggle with so-called cross-allergies, particularly to pome and stone fruit as well as nuts. Around 20 per cent of these allergy sufferers can no longer tolerate apples either and banish this healthy fruit completely from their diet to avoid painful tingling, a furry tongue or