A survey of 785 adults in the Netherlands, using validated questionnaires found that 6.25% were avoiding wheat due to reported symptoms related to gluten ingestion. The most popular use of a wheat-free diet is to alleviate symptoms related to irritable bowel disorder (IBS); however, it is possible that only one-third of patients with IBS will continue to experience symptomatic relief on long-term wheat avoidance.
Wheat can also cause a true, severe allergic reaction. Jiang et al. reviewed 1 952 cases of anaphylaxis in 907 patients, most of whom were adults. Analysis of the most severe allergic episodes showed that 57% were triggered by wheat.
Individual cases of anaphylaxis to oats have been reported, as has a series of patients with allergy to millet, often consumed as a healthy alternative cereal to wheat.
A retrospective study on 2.7 million patients identified 3.6% had one or more food allergies and intolerances, with fruits and vegetables being the second most common food group identified as trigger foods, with a prevalence of 0.7%.
7% of children attending hospital for reported anaphylaxis had a confirmed allergy to fruits, and data from the European Anaphylaxis Registry also reported that fruits were also responsible for 5% of all causes of anaphylaxis to foods in children and adolescents.
Another study showed that 20% of all food anaphylaxis reactions were caused by fruits and vegetables, often associated with mugwort sensitisation, especially if peaches were the trigger food.
Fruits and vegetables can provoke a severe allergic reaction, but are often considered as benign, and thus an unlikely cause of allergy by the general public and healthcare professionals alike. The internet is often blamed for misinformation, but it is easy to dismiss symptoms to fruits, vegetables and especially to wheat as intolerance rather than allergy. Accurate assessment to assess whether symptoms to these foods represent a true allergy is essential.