Food Standards Agency - Allergy Basics and Statistics - AAW 2016

Most allergies are not food related, or rather indirectly so. Hayfever and asthma are not food related but things like growing rapeseed (Canola / colza) have caused problems along the lines you suggest. However as a farmer with a most unfortunate hayfever allergy to rapeseed I can actually eat the stuff quite cheerfully. 28% of UK adults have some allergic reaction, just under half of this figure have more than one allergen, but only a tiny number of people have food allergies (as opposed to intolerances). Very few people are allergic to prawns.