Table 1.

Dietary factors and etiology in pediatric IBD. IBD = inflammatory bowel disease, UC = ulcerative colitis, CD = Crohn’s disease, LC = long chain.

Dietary Factors and Etiology in Pediatric IBD
Author/Year	Study Type	Population	Main Findings
Gilat et al. 1987 [14]	Case-control study	Patients with IBD (n = 499; UC = 197, CD = 302) aged < 25 years with disease onset before 20 years of age. For each patient two age and sex matched health controls.	- Patients with CD and UC consumed significantly lower fruits and vegetables than controls (p < 0.01). For UC: low consumption (0 and <1/day) vs. high consumption (1–3 and >4/day) OR = 0.77; 95% CI 0.45 to 1.35. For CD: low consumption (0 and <1/day) vs. high consumption (1–3 and >4/day) OR = 0.58; 95% CI 0.37 to 0.91. - No significant differences were found between patients and controls in the frequency of breast feeding (p < 0.01), cereal consumption (p < 0.01) and sugar added to milk in infancy (p < 0.01).
Japanese Epidemiology Group of the Research Committee of IBD, 1994 [10]	Case-control study	Patients with UC (n = 101) who were aged 10–39 years at the time of disease onset. Healthy control subjects (n = 143).	- Combined consumption of Western foods (bread for breakfast, butter, margarine, cheese, meats, and ham and sausage) was significantly related to an increased risk of UC (Relative risk (RR) for low consumption 1.0, RR for intermediate consumption 1.9; 95% CI 1.0 to 3.7, RR for high consumption 2.1, 95% CI 1.0 to 4.1; trend, p = 0.04). - Margarine (as an individual Western food item) was positively associated with UC (trend, p = 0.005).
Baron et al. 2005 [15]	Case-control study	IBD patients (n = 282; CD 222, UC 60) with onset before 17 years of age and healthy controls matched for age, sex, and geographical location (n = 282).	- Breastfeeding either partially or exclusively was a risk factor for CD (CD OR = 2.1; 95% CI 1.3 to 3.4, p = 0.003). - Regular drinking of tap water was a protective factor for CD (CD = OR 0.6; 95% CI 0.3 to 1, p = 0.05).
Amre et al. 2007 [11]	Case-control study	Children and adolescents ≤20 years (n = 130), newly diagnosed with CD mean age at diagnosis (±SD) 14.2 ± 2.7 years. Healthy controls matched for age and sex (n = 202).	- Higher amounts of vegetables (OR = 0.69; 95% CI 0.33 to 1.44, p = 0.03), fruits (OR = 0.49; 95% CI 0.25–0.96, p = 0.02), fish (OR = 0.46; 95% CI 0.20 to 1.06, p = 0.02) and dietary fiber (OR = 0.12; 95%, CI 0.04 to 0.37, p < 0.001) protected from CD. - Consumption of LC ω-3 (OR = 0.44; 95%, CI 0.19 to 1.00, p < 0.001) were negatively associated with CD. - A higher ratio of LC ω-3/ω-6 fatty acids (OR = 0.32, 95% CI 0.14 to 0.71, p = 0.02) were significantly associated with lower risks for CD.
D’Souza et al. 2008 [12]	Case-control study	Children and adolescents ≤20 years (n = 149), newly diagnosed with CD mean age at diagnosis (±SD) 13.3 ± 2.6 years. Healthy controls matched for age and sex (n = 251).	- Meats, fatty foods and desserts (OR = 4.7; 95% CI 1.6 to 14.2) were positively associated with CD. - Vegetables, fruits, olive oil, fish, grains, and nuts were inversely associated with CD in both genders (girls: OR = 0.3; 95% CI 0.1 to 0.9; boys: OR = 0.2; 95% CI 0.1 to 0.5).
Jakobsen et al. 2012 [13]	Case-control study	Children and adolescents with IBD (n = 118; CD 59, UC 56, IBD-unclassified 3) aged <15 years. Healthy controls matched for age and sex (n = 477).	- High sugar intakes were a risk factor for IBD (IBD OR = 2.5; 95% CI 1.0 to 6.2, CD OR = 2.9; 95% CI 1.0 to 8.5). - Protective factors were daily vs. less than daily vegetable consumption (CD OR = 0.3; 95% CI 0.1 to 1.0, UC OR = 0.3; 95% CI 0.1 to 0.8) and whole-meal bread consumption (IBD OR = 0.5; 95% CI 0.3 to 0.9, CD OR = 0.4; 95% CI 0.2 to 0.9).