More people are experiencing severe food allergies than ever before - but why?

The recent inquest into the death of Natasha Ednan-Laperouse from anaphylaxis after eating a Pret A Manger baguette she was unaware contained sesame, could lead to a change in labelling legislation, writes Matthew Smith of the University of Strathclyde

Indeed, a recent investigation found that undeclared allergens were present in a quarter of foods sampled. But a more fundamental issue needs to be addressed: why are more people experiencing severe food allergies than ever before?