People with pollen allergies can develop allergic reactions to fresh fruits, vegetables and/or nuts. This is called the pollen-food allergy syndrome or oral allergy syndrome – because symptoms often occur around or within the mouth. It is typically diagnosed in adolescents and young adults, though it can show up in childhood and later adulthood.
The Protein Connection
Pollen-food allergy may occur because pollens contain proteins that are also found in certain veggies, nuts, and fruits. Antibodies to a specific pollen may cross-react with foods harboring the same type of protein, triggering an allergic response.
For instance, birch tree pollen has a protein similar to one in foods such as apples, peaches, pears, carrots, celery, almonds, and peanuts. So individuals with a birch pollen allergy may also have an allergic response when eating these protein-related foods.
Most people with a pollen-related fruit or veggie allergy can tolerate the triggering foods when they are cooked since the proteins are sensitive to heat and digestive enzymes. However, this does not apply to nuts.
People without pollen allergies can also be allergic to fruit and vegetable protein. These individuals tend to have stronger allergic reactions because the responsible proteins are different. They are also more stable in high temperatures and gastric juices.
Reactions in pollen-food syndrome are usually limited to the mouth and throat areas. Symptoms such as itchiness and swelling generally occur within minutes of eating the offending food and maybe worse during pollen season.
A system-wide reaction risk is low since the protein is degraded by digestive enzymes. The risk of a systemic response is believed to be less than 10 percent; anaphylaxis risk is 1.7 percent. The pollen-foods that most often spark a system-wide reaction are peaches, mustard, nuts, and peanuts.
Though the risk of serious pollen-food reaction is minimal, the intensity of future reactions in unpredictable. It is best to avoid the culprit nuts and peanuts in raw or cooked forms and to enjoy cooked-only servings of the triggering fruits and vegetables. Consult an allergist for testing, definitive diagnosis and wise recommendations.