An association between fiber intake and allergic diseases in children has been reported; however, many studies have not been conducted to assess this association in adults. We aimed to evaluate the association between dietary fiber intake and allergic diseases (asthma, allergic rhinitis, and atopic dermatitis) among 10,479 adults using data from the Korean National Health and Nutrition Examination Survey (2010–2011). As dietary fiber intake increased, the prevalence of asthma (Q4 adjusted odds ratio (OR): 0.656; 95% confidence interval (CI): 0.48–0.91, p for trend < 0.0001) and atopic dermatitis (Q3 crude OR: 0.746; 95% CI: 0.57–0.98; Q4 adjusted OR: 0.712; 95% CI: 0.50–1.01, p for trend < 0.0001) decreased. The prevalence of allergic rhinitis (Q2 adjusted OR: 0.840; 95% CI: 0.70–1.00, p for trend < 0.0001) tended to decrease, especially in males. Subgroup analysis revealed that fiber intake reduced allergic rhinitis symptoms, including watery rhinorrhea (Q3 adjusted OR: 0.734; 95% CI: 0.55–0.97; Q4 adjusted OR: 0.722; 95% CI: 0.54–0.97) and dog allergen sensitization (Q3 adjusted OR: 0.319; 95% CI: 0.13–0.82; Q4 adjusted OR: 0.338; 95% CI: 0.13–0.86), exclusively in males. Thus, dietary fiber intake influences allergic diseases in adults, especially males.

Chronic rhinosinusitis is known to be influenced by cigarette exposure; however, this relationship is based on the presence of nasal polyps, and objective measurements of cigarette exposure in chronic rhinosinusitis are not well established. This study aimed to estimate the association between chronic rhinosinusitis and smoking status based on self-reported questionnaires and urinary cotinine levels according to the presence of nasal polyps. We analyzed a total of 23,621 participants who participated from the fifth Korea National Health and Nutrition Examination Survey (2010–2012). Serum total and specific IgE level were measured. Higher prevalence of chronic rhinosinusitis with nasal polyps was associated with current smoking status (OR = 1.43, 95% CI = 1.00–2.03). This association was prevalent in participants aged ≤ 50 years (OR = 1.76, 95% CI = 1.01–3.05), and higher urinary cotinine level showed correlation with higher prevalence of chronic rhinosinusitis with nasal polyps in this age group (OR = 1.04, 95% CI = 1.00–1.08). In addition, positive correlation between serum total IgE and urinary cotinine levels was greater in patients with chronic rhinosinusitis (β = 0.493, 95% CI = 0.071–0.916) than in controls (β = 0.062, 95% CI = 0.021–0.103). Aggressive smoking interventions should be performed in patients with chronic rhinosinusitis with nasal polyp, especially in cases of young adults or high serum IgE levels.