(UPI) -- Discoveries by Danish researchers could help wine-makers develop low-allergenic vintages -- wines with less potential to trigger allergy symptoms. Scientist Giuseppe Palmisano of University of Southern Denmark in Odense and colleagues identified 28 glycoproteins -- proteins coated with sugars produced naturally as grapes ferment -- that may be causing the headaches, stuffy noses, skin rash and other more serious allergy symptoms such as difficulty breathing suffered by 500 million people worldwide if they drink wine.