Background Until the present, no comprehensive studies evaluating the prevalence of food allergy and non-allergic food hypersensitivity (FA/NAFH) in adults have been done in Turkey or its surrounding countries.
Objective This large population-based study was planned to identify the confirmed prevalence of adverse reactions to food in adults in Istanbul.
Methods A total of 17 064 telephone numbers were randomly selected from both the European and Asian sides of Istanbul, and the 11 816 subjects who agreed to participate in the study were addressed with a questionnaire of eight items. Those who disclosed food-related complaints in this survey were called again and a similar questionnaire was repeated. The respondents who were suspected of having food allergy or food hypersensitivity were invited for a personal clinical investigation that included double-blind, placebo-controlled food challenge tests.
Results The lifetime prevalence of self-reported FA/NAFH was found to be 9.5% [1118/11 816; 95% confidence interval (CI): 8.94–10.00%]. After the clinical investigations, the point prevalence of FA/NAFH, which also included the ‘possible FA/NAFH group’, was found to be as low as 0.3% (30/11 816; 95% CI: 0.17–0.36%), and the FA/NAFH rates assessed by double-blind, placebo-controlled food challenge tests were 0.1% (12/11 816; 95% CI: 0.05–0.18%) and 0.1% (11/11 816; 95% CI: 0.05–0.17%), respectively. The most significant factor influencing FA/NAFH was familial atopy (adjusted OR 4.3; 95% CI: 3.67–4.99), and the most related atopic disease was itching dermatitis/urticaria (adjusted OR: 3.9; 95% CI: 3.31–4.54).
Conclusion We may conclude that FA/NAFH in the Turkish population seems to be low when compared with Northern and Western European countries. This may be due to genetic, cultural or dietary factors, and further studies evaluating the reasons for this low prevalence of FA/NAFH in our population are needed.