Pre-illness changes in dietary habits and diet as a risk factor for inflammatory bowel disease: A case-control study

Table 1 Demographic and clinical features of inflammatory bowel disease cases and healthy controls

	Cases	Controls
	(n = 83)	(n = 160)
Sex (M/F)	49/34	97/63
Age (mean ± SD)	37.5 ± 15.2	40.4 ± 14.6
Social status, n (%)
Unmarried	50 (60.3)	83 (51.9)
Married	26 (31.3)	69 (43.1)
Divorced/widowed	7 (8.4)	8 (5.0)
Years of education (mean-SD)	12.4-3.5	11.5-4.2
Body mass index, kg2/cm (mean-SD)	26.1-9.3	29.1-10.8
Smoking habit, n (%)
Never	32 (38.6)	80 (50.0)
Smokers	29 (34.9)	41 (35.6)
Ex-smokers	22 (26.5)	39 (24.4)
No. cigarettes/d (smokers) mean (range)	13.4 (3-50)	14.7 (5-30)
Disease location (Crohn’s disease) n = 42
Ileum, n (%)	18 (42.9)
Ileum and colon	13 (31.0)	/
Colon	11 (26.2)
Disease location (ulcerative colitis) n = 41
Proctitis	5 (12.2)
Left sided colitis	22 (53.7)	/
Pancolitis	14 (34.1)
Disease behaviour (Crohn’s disease)
Inflammatory (B1)	27 (64.3)
Stricturing (B2)	8 (19.0)	/
Penetrating (B3)	7 (16.7)

Table 2 Association between changes in pre-illness dietary habits and symptoms in inflammatory bowel disease patients

	Changes in diet
	Ulcerative colitis		Crohn’s disease
	No (26)	Yes (15)	No (25)	Yes (17)
Duration of symptoms
Short ( ≤ 3 mo)	14 (53.85)	4 (26.67)	8 (32.00)	4 (23.53)
Intermediate (4-10 mo)	7 (26.92)	4 (26.67)	13 (52.00)	4 (23.53)
Long (> 10 mo)	5 (19.23)	7 (46.66)	4 (16.00)	9 (52.94)a
Median, range (mo)	3 (1-15)	7 (1-84)	5 (1-30)	12 (1-48)a
Weight loss
Absent/low (< 2 kg)	12 (46.15)	4 (26.67)	8 (32.00)	3 (16.65)
Moderate (2-6 kg)	8 (30.77)	3 (20.00)	11 (44.00)	8 (47.06)
Severe (> 6 kg)	6 (23.08)	8 (53.33)	6 (24.00)	6 (35.29)
Abdominal pain
No	9 (34.61)	3 (20.00)	4 (16.00)	1 (5.88)
Yes	17 (65.39)	12 (80.00)	21 (84.00)	16 (94.12)
Diarrhoea
No	5 (19.23)	1 (6.67)	4 (16.00)	1 (5.88)
Yes	21 (80.77)	14 (93.33)	21 (84.00)	16 (94.12)
Rectal bleeding
No	9 (34.62)	5 (33.33)	13 (52.00)	12 (70.59)
Yes	17 (65.38)	10 (66.67)	12 (48.00)	5 (29.41)

^aP < 0.05.

Table 3 Association between pre-illness intake of foods and beverages and risk of ulcerative colitis in patients who did not modify the diet before diagnosis

	Controls	Ulcerative colitis
	n (%)	n (%)	OR1 (95% CI)
Pasta and/or rice
Low	67 (41.88)	7 (26.92)	2
Moderate	68 (42.50)	12 (46.15)	1.89 (0.66-5.41)
High	25 (15.63)	7 (26.92)	3.38 (0.99-11.47)
Bread
Low	60 (37.50)	6 (23.08)	2
Moderate	55 (34.38)	9 (34.62)	1.31 (0.42-4.13)
High	45 (28.13)	11 (42.31)	2.40 (0.80-7.26)
Sweets and cakes
Low	52 (32.50)	10 (38.46)	2
Moderate	49 (30.63)	4 (15.38)	0.37 (0.10-1.33)
High	59 (36.88)	12 (46.15)	0.96 (0.36-2.51)
Red meat
Low	73 (45.63)	12 (46.15)	2
Moderate	38 (23.75)	8 (30.77)	1.22 (0.45-3.32)
High	49 (30.63)	6 (23.08)	0.63 (0.20-1.94)
White meat
Low	45 (28.13)	5 (19.23)	2
Moderate	70 (43.75)	17 (65.38)	2.04 (0.69-6.05)
High	45 (28.13)	4 (15.38)	0.75 (0.19-3.04)
Tuna fish
Low	37 (23.13)	10 (38.46)	2
Moderate	48 (30.00)	6 (23.08)	0.43 (0.13-1.37)
High	75 (46.88)	10 (38.46)	0.49 (0.18-1.36)
Fish
Low	61 (38.13)	17 (65.38)	2
Moderate	39 (24.38)	3 (11.54)	0.33 (0.09-1.26)
High	60 (37.50)	6 (23.08)	0.33 (0.11-0.92)
Processed meat
Low	50 (31.25)	9 (34.62)	2
Moderate	57 (35.63)	10 (38.46)	0.82 (0.28-2.36)
High	53 (33.13)	7 (26.92)	0.63 (0.21-1.91)
Milk
Low	45 (28.13)	13 (50.00)	2
Moderate	36 (22.50)	3 (11.54)	0.30 (0.08-1.19)
High	79 (49.38)	10 (38.46)	0.55 (0.21-1.40)
Cheese
Low	43 (26.88)	8 (30.77)	2
Moderate	70 (43.75)	11 (42.31)	0.93 (0.33-2.63)
High	47 (29.38)	7 (26.92)	0.98 (0.31-3.12)
Eggs
Low	44 (27.50)	11 (42.31)	2
Moderate	51 (31.88)	11 (42.31)	0.78 (0.30-2.06)
High	65 (40.63)	4 (15.38)	0.21 (0.06-0.73)
Potatoes
Low	25 (15.63)	10 (38.46)	2
Moderate	78 (48.75)	11 (42.31)	0.39 (0.14-1.09)
High	57 (35.63)	5 (19.23)	0.24 (0.09-0.83)
Vegetables
Low	44 (27.67)	11 (42.31)	2
Moderate	67 (42.14)	10 (38.46)	0.49 (0.18-1.35)
High	48 (30.19)	5 (19.23)	0.37 (0.11-1.21)
Fruits
Low	48 (30.00)	9 (34.62)	2
Moderate	61 (38.13)	11 (42.31)	1.12 (0.42-3.01)
High	51 (31.88)	6 (23.08)	0.41 (0.13-1.35)
Refined sugar
Low	57 (35.63)	9 (34.62)	2
Moderate	45 (28.13)	12 (46.15)	1.52 (0.57-4.09)
High	58 (36.25)	5 (19.23)	0.57 (0.17-1.87)
Butter
Low	28 (17.50)	1 (3.85)	2
Moderate	88 (55.00)	18 (69.23)	6.02 (0.75-47.97)
High	44 (27.50)	7 (26.92)	5.18 (0.58-46.20)
Margarine
Low	57 (35.63)	1 (3.85)	2
Moderate	84 (52.50)	19 (73.08)	11.80 (1.51-91.99)
High	19 (11.88)	6 (23.08)	21.37 (2.32-196.6)
Olive oil
Low	47 (29.38)	6 (23.08)	2
Moderate	88 (55.00)	16 (61.54)	1.40 (0.50-3.93)
High	25 (15.63)	4 (15.38)	1.16 (0.29-4.63)
Seed oil
Low	33 (20.63)	1 (3.85)	2
Moderate	97 (60.63)	22 (84.62)	7.26 (0.93-56.53)
High	30 (18.75)	3 (11.54)	3.82 (0.36-40.14)

¹From unconditional logistic regression models including terms for age (5-year groups), sex, years of education, tobacco consumption (never, ex-smoker, current smoker of < 15, 15-24, ≥ 25 cigarettes/d) and body mass index (quintiles);

²Reference category.

Table 4 Association between pre-illness intake of foods and beverages and risk of Crohn's disease in patients who did not modify the diet before diagnosis

	Controls	Crohn’s disease
	n (%)	n (%)	OR1 (95% CI)
Pasta and/or rice
Low	67 (41.88)	8 (32.00)	2
Moderate	68 (42.50)	14 (56.00)	1.59 (0.61-4.17)
High	25 (15.63)	3 (12.00)	1.01 (0.24-4.34)
Bread
Low	60 (37.50)	6 (24.00)	2
Moderate	55 (34.38)	8 (32.00)	1.25 (0.38-4.04)
High	45 (28.13)	11 (44.00)	2.47 (0.81-7.56)
Sweets and cakes
Low	52 (32.50)	8 (32.00)	2
Moderate	49 (30.63)	4 (16.00)	0.43 (0.11-1.63)
High	59 (36.88)	13 (52.00)	1.21 (0.44-3.29)
Red meat
Low	73 (45.63)	8 (32.00)	2
Moderate	38 (23.75)	6 (24.00)	1.25 (0.38-4.07)
High	49 (30.63)	11 (44.00)	2.42 (0.85-6.85)
White meat
Low	45 (28.13)	8 (32.00)	2
Moderate	70 (43.75)	15 (60.00)	1.33 (0.50-3.52)
High	45 (28.13)	2 (8.00)	0.25 (0.05-1.27)
Tuna fish
Low	37 (23.13)	13 (52.00)	2
Moderate	48 (30.00)	6 (24.00)	1.31 (0.35-4.87)
High	75 (46.88)	6 (24.00)	0.25 (0.08-0.77)
Fish
Low	61 (38.13)	16 (64.00)	2
Moderate	39 (24.38)	6 (24.00)	0.57 (0.19-1.72)
High	60 (37.50)	3 (12.00)	0.18 (0.05-0.67)
Processed meat
Low	50 (31.25)	2 (8.00)	2
Moderate	57 (35.63)	18 (72.00)	7.80 (1.61-37.89)
High	53 (33.13)	5 (20.00)	1.97 (0.35-11.03)
Milk
Low	45 (28.13)	7 (28.00)	2
Moderate	36 (22.50)	2 (8.00)	0.41 (0.07-2.18)
High	79 (49.38)	16 (64.00)	1.55 (0.57-4.19)
Cheese
Low	43 (26.88)	5 (20.00)	2
Moderate	70 (43.75)	5 (20.00)	0.54 (0.14-2.06)
High	47 (29.38)	15 (60.00)	3.70 (1.14-12.01)
Eggs
Low	44 (27.50)	10 (40.00)	2
Moderate	51 (31.88)	9 (36.00)	0.85 (0.30-2.40)
High	65 (40.63)	6 (24.00)	0.42 (0.14-1.29)
Potatoes
Low	25 (15.63)	7 (28.00)	2
Moderate	78 (48.75)	13 (52.00)	0.60 (0.19-1.83)
High	57 (35.63)	5 (20.00)	0.24 (0.06-0.91)
Vegetables
Low	44 (27.67)	14 (56.00)	2
Moderate	67 (42.14)	7 (28.00)	0.26 (0.09-0.78)
High	48 (30.19)	4 (16.00)	0.21 (0.05-0.78)
Fruits
Low	48 (30.00)	9 (36.00)	2
Moderate	61 (38.13)	8 (32.00)	0.78 (0.26-2.30)
High	51 (31.88)	8 (32.00)	0.76 (0.26-2.21)
Refined sugar
Low	57 (35.63)	8 (32.00)	2
Moderate	45 (28.13)	12 (48.00)	1.61 (0.58-4.42)
High	58 (36.25)	5 (20.00)	0.58 (0.17-1.97)
Butter
Low	28 (17.50)	1 (4.00)	2
Moderate	88 (55.00)	20 (80.00)	6.07 (0.75-49.20)
High	44 (27.50)	4 (16.00)	1.84 (0.18-18.19)
Margarine
Low	57 (35.63)	8 (32.00)	2
Moderate	84 (52.50)	13 (52.00)	1.07 (0.40-2.84)
High	19 (11.88)	4 (16.00)	1.17 (0.29-4.74)
Olive oil
Low	47 (29.38)	10 (40.00)	2
Moderate	88 (55.00)	10 (40.00)	0.60 (0.22-1.61)
High	25 (15.63)	5 (20.00)	0.98 (0.29-3.35)
Seed oil
Low	33 (20.63)	6 (24.00)	2
Moderate	97 (60.63)	15 (60.00)	0.84 (0.29-2.43)
High	30 (18.75)	4 (16.00)	0.66 (0.16-2.76)

¹From unconditional logistic regression models including terms for age (5-year groups), sex, years of education, tobacco consumption (never, ex-smoker, current smoker of < 15, 15-24, ≥ 25 cigarettes/d) and body mass index (quintiles).

²Reference category.

Table 5 Odds ratios¹ and corresponding 95% CI for pre-illness intake of foods according to the disease location for Crohn’s disease patients

	Small bowel	Colon
Pasta and/or rice	1.44 (0.71-2.92)	0.65 (0.20-2.13)
Bread	2.61 (1.26-5.41)2	0.27 (0.06-1.10)
Sweets and cakes	1.17 (0.64-2.14)	1.39 (0.53-3.63)
Red meat	1.58 (0.88-2.82)	1.23 (0.49-3.12)
White meat	0.74 (0.38-1.46)	0.40 (0.12-1.29)
Tuna fish	0.48 (0.26-0.91)2	0.33 (0.11-0.98)2
Fish	0.48 (0.24-0.93)2	0.41 (0.13-1.29)
Processed meat	1.31 (0.67-2.58)	0.74 (0.27-2.01)
Milk	1.30 (0.71-2.36)	1.13 (0.46-2.78)
Cheese	2.61 (1.26-5.41)2	1.94 (0.62-6.09)
Eggs	0.67 (0.36-1.23)	0.69 (0.27-1.80)
Potatoes	0.50 (0.23-1.07)	0.46 (0.15-1.41)
Vegetables	0.43 (0.21-0.88)2	0.60 (0.20-1.83)
Fruits	0.82 (0.42-1.58)	0.83 (0.29-2.36)
Refined sugar	0.80 (0.44-1.46)	0.77 (0.31-1.95)
Butter	0.83 (0.39-1.79)	1.44 (0.41-5.12)
Margarine	1.10 (0.51-2.36)	1.83 (0.58-5.76)
Olive oil	1.20 (0.58-2.51)	0.24 (0.06-1.00)2
Seed oil	0.81 (0.37-1.79)	1.05 (0.32-3.42)

¹From unconditional logistic regression models including terms for age (5-year groups), sex, years of education, tobacco consumption (never, ex-smoker, current smoker of < 15, 15-24, ≥ 25 cigarettes/d) and body mass index (quintiles) and according to an increase of 1 tertile level;

²Significant associations.

Table 6 Food group loadings for 3 dietary patterns extracted by factor analyses

	Factor 1	Factor 2	Factor 3
Pasta and/or rice	0.30	-0.25	0.32
Bread	-0.01	-0.40	0.51
Soft, sweets and cakes	0.45	-0.28	0.09
Red meat	0.57	0.30	0.23
White meat	0.45	0.49	-0.02
Tuna fish	0.43	0.60	-0.11
Fish	0.33	0.58	-0.12
Processed meat	0.46	0.04	-0.02
Milk	0.03	-0.33	0.04
Cheese	0.02	0.19	0.56
Eggs	-0.05	0.69	0.08
Potatoes	0.09	0.58	0.01
Vegetables	-0.52	0.22	0.32
Fruit	-0.53	-0.01	0.25
Refined sugar	-0.01	-0.03	0.60
Butter	0.47	0.20	0.27
Margarine	0.46	0.29	-0.02
Olive oil	-0.17	-0.32	0.44
Seed oil	0.39	0.13	0.07
	Refined	Prudent	Healthy
	OR (95% CI)	OR1 (95% CI)	OR (95% CI)
Ulcerative colitis
Low2	13	13	13
Moderate	2.29 (0.70-7.32)	0.32 (0.11-0.90)	0.80 (0.28-2.28)
High	2.46 (0.77-7.83)	0.15 (0.04-0.51)	0.95 (0.33-2.76)
Crohn’s disease
Low	13	13	13
Moderate	1.51 (0.45-4.99)	0.47 (0.17-1.27)	0.57 (0.18-1.78)
High	2.15 (0.67-6.87)	0.13 (0.03-0.51)	1.39 (0.49-3.95)

¹From unconditional logistic regression models including terms for age (5-year groups), sex, years of education, tobacco consumption (never, ex-smoker, current smoker of < 15, 15-24, ≥ 25 cigarettes/d) and body mass index (quintiles);

²Tertiles of factor scores;

³Reference categories.