With this spring's allergy season forecast to be more difficult than usual for birch pollen sufferers, some are experiencing reactions to certain food items, a phenomenon known as cross-reactivity.
One in five people in Finland suffer from seasonal allergy symptoms. These include sneezing, nasal congestion, runny eyes and nose, itchy throat and eyes.
Certain foods can exacerbate pollen symptoms, and around half of those allergic to birch also experience symptoms from certain foods.
"The protein structure of certain vegetables and fruits resembles that of pollen. When these food items come into contact with the lips or mouth, the body mistakenly believes that it is encountering pollen," said Katariina Ijäs of the Finnish Allergy, Skin and Asthma Federation.
Raw vegetables and fruits are the most allergenic. That said, reactions are individual—the same items do not cause cross-allergies for everyone. Those experiencing symptoms from fruits and vegetables during the spring allergy season usually see symptoms fade as pollen counts drop.
The most common raw foods triggering cross-allergies include carrot, potato, bell pepper, parsnip, tomato, celery, apple, peach, plum and kiwi. Almonds—as well as many other nuts—can cause allergic reactions.
"Spices can also induce symptoms. For example, cinnamon, ginger, and peppers can be triggers for symptoms in the mouth or throat," Ijäs explained.
Heating helps
Cross-allergy symptoms are generally mild and do not cause severe allergic reactions. However, the severity of symptoms varies.
"Symptoms are unpleasant and include swelling and soreness of the lips," said Ijäs.
Processing foods by heating, freezing or grating can offer some relief. This is because processing alters the protein structure in a way that it no longer triggers symptoms.
Turku University carries the latest pollen count updates here.