Food groups, diet quality and colorectal cancer risk in the Basque Country

Table 1 Food group definitions

Food group	Food items
Red and processed meat
Red meat	Beef, pork and lamb, minced meat, hamburgers, meatballs
Processed meat	Ham, sausage, salami, mortadella, black pudding or blood sausage
Egg	Egg
Fish	White fish (hake, grouper, sole, cod) and fatty fish (sardine, tuna, salmon, mackerel)
Milk/dairy products
Non-cheese products	Whole milk, semi-skimmed milk, skimmed milk, whole yogurt, skimmed yogurt and dairy desserts
Cheese	Burgos cheese, curd, cottage and cheeses low in calories, mature, semi-mature and creamy cheese
Fiber-containing foods
Fruits	Orange, tangerine, apple, pear, banana, peach, raisins, prunes, dried figs... natural fruit juices
Vegetables	Salads, green beans, chard, spinach... garnish vegetables (eggplant, mushrooms, peppers...), garlic, onion
Whole grains	Whole grain pasta, brown rice, whole grain cookies, whole breakfast cereals (Muesli, All-Bran)
Nuts	Walnuts, almonds, hazelnuts, peanuts
Fat	Vegetable oils (olive, sunflower, corn, soy), butter, margarine, mayonnaise
Sweet and added sugar	Chocolate, breakfast cereals, cookies, muffins, donuts, honey, sugar, commercial fruit juice, soft-drinks, cakes, pies
Alcoholic beverages	Beer, wine, hard cider, vermouth, whiskey, rum, gin, brandy, cocktails

Table 2 General characteristics of the sample studied

Characteristics	Cases (n = 308)		Controls (n = 308)		P value
Sex, men, n (%)	204 (66.2)		204 (66.2)
Age, yr, mean SD	61.5	5.2	61.1	5.5	0.093
Schooling, %
No education/primary education	36.7		29.2
Technical/secondary education	48.0		44.5
University degree	15.3		26.3		0.005
Economic activity, %
Working	27.9		32.1
Unemployed	5.2		3.2
Retired	58.8		56.2
Housework	8.1		8.4		0.496
Last work, %
Employer or businessman/women	19.2		17.9
Steady salaried employee	75.0		71.8
Temporary salaried employee or member of a cooperative	0.6		4.5
Household help and other activities without salary	5.1		5.8		0.073
Smoking status, %
Never	27.9		38.6
Past/current	72.1		61.4		0.004
Time to quit smoking
≥ 11 yr	67.2		66.7
< 11 yr	32.8		33.3		0.931
Intensity of smoking1
≤ 15 cigarettes/d	50.7		33.1
> 15 cigarettes/d	49.3		66.9		0.003
Physical exercise, %
< 15 min/d of cycling/sports	79.2		65.9
≥ 15 min/d of cycling/sports	20.8		34.1		< 0.001
BMI, %
Underweight	6.5		7.8		0.033
Normal weight	26.0		34.1
Overweight/obesity	67.5		58.1
Energy intake (kcal/d), mean SD	1769.9	383.4	1736.6	388.2	0.172
DI,%2
Q1-3	47.1		65.6
Q4-5	18.8		29.5		< 0.001
PRM,%2
L1-2	15.6		12.3
L3-4	83.4		79.2		< 0.001

¹Percentages were calculated excluding never smokers.

²Valid percentages. BMI: Body mass index; DI: Deprivation index (This index was successfully assigned to 80.2% of the study sample); L: Level; PRM: Predictive risk modelling (This index was successfully assigned to 95.1% of the study sample); Q: Quintile; SD: Standard deviation.

Table 3 Food group intakes of the sample studied

Food groups, g/d	Cases (n = 308)		Controls (n = 308)		P value
	mean	SD	mean	SD
Red and processed meat	70.9	36.6	66.0	39.7	0.064
Red meat	49.7	30.5	46.1	31.0	0.130
Processed meat	21.2	16.6	19.9	17.2	0.155
Total fish	76.8	39.2	77.6	40.9	0.540
White fish	40.9	25.2	44.1	27.4	0.055
Fatty fish	35.9	22.6	33.6	24.1	0.236
Eggs	20.8	12.7	18.7	11.5	0.038
Milk/dairy products	264.7	153.4	271.0	119.4	0.310
Non-cheese dairy products	246.0	152.4	253.8	118.5	0.203
Total cheeses	18.8	17.4	17.1	16.8	0.172
Fresh cheeses1	6.9	10.3	7.1	13.3	0.867
Other cheeses2	11.7	11.8	10.1	10.7	0.172
Fiber-containing foods	570.3	243.9	564.8	214.1	0.761
Fruits (including natural juices)	330.2	202.5	322.6	168.2	0.791
Vegetables	202.1	88.8	200.6	90.9	0.803
Whole grains	14.4	19.9	18.8	23.4	0.012
Fat	35.5	6.9	34.6	6.4	0.064
Nuts	9.1	10.1	10.9	10.5	0.055
Sweets and added sugar	108.3	95.4	110.7	116.5	0.969
Alcoholic beverages	103.4	100.7	96.8	105.9	0.269

¹Fresh cheeses, e.g., Burgos cheese and cheeses low in calories.

²Other cheeses, mature, semi-mature and creamy cheeses. SD: Standard deviation.

Table 4 Association between main food group in and colorectal cancer risk

Main food group intakes1	No., case/control	Model I2	Model II3	Model III4
		OR (95%CI)	OR (95%CI)	OR (95%CI)
Red and processed meat
T1	90/102	1.00	1.00	1.00
T2	97/103	1.06 (0.72-1.57)	1.02 (0.61-1.72)	1.08 (0.61-1.94)
T3	121/109	1.32 (0.91-1.93)	1.65 (0.99-2.75)	1.26 (0.71-2.23)
P		0.314	< 0.001	-
Fish
T1	95/105	1.00	1.00	1.00
T2	77/103	0.82 (0.53-1.25)	0.97 (0.56-1.68)	0.83 (0.46-1.51)
T3	136/105	1.49 (1.01-2.20)	1.06 (0.62-1.79)	1.25 (0.68-2.29)
P		0.008	< 0.001	-
Eggs
T1	71/98	1.00	1.00	1.00
T2	107/116	1.15 (0.77-1.72)	1.04 (0.62-1.76)	0.97 (0.61-1.93)
T3	130/104	1.55 (1.03-2.33)	1.72 (1.00-2.94)	1.26 (0.71-2.23)
P		0.081	< 0.001	-
Milk/dairy products
T1	60/102	1.00	1.00	1.00
T2	127/104	2.05 (1.35-3.11)	2.02 (1.19-3.42)	1.97 (1.10-3.53)
T3	121/102	2.00 (1.31-3.05)	2.12 (1.25-3.84)	1.80 (0.95-3.42)
P		< 0.001	< 0.001	-
Fiber-containing foods
T1	121/102	1.00	1.00	1.00
T2	75/101	0.60 (0.39-0.92)	0.47 (0.26-0.85)	0.49 (0.25-0.95)
T3	112/105	0.86 (0.58-1.28)	0.63 (0.36-1.11)	0.65 (0.35-1.21)
P		0.048	< 0.001	-
Nuts
T1	118/103	1.00	1.00	1.00
T2	118/108	0.97 (0.67-1.42)	0.87 (0.53-1.44)	0.70 (0.37-1.31)
T3	72/97	0.67 (0.43-0.97)	0.58 (0.34-1.00)	0.59 (0.30-1.18)
P		0.074	< 0.001	-
Fat
T1	86/100	1.00	1.00	1.00
T2	101/105	1.12 (0.75-1.67)	0.94 (0.56-1.59)	0.83 (0.45-1.51)
T3	121/100	1.34 (0.92-1.97)	1.46 (0.85-2.50)	1.25 (0.68-2.29)
P		0.297	< 0.001	-
Sweets and added sugar
T1	82/120	1.00	1.00	1.00
T2	120/103	1.47 (0.99-2.20)	1.67 (0.98-2.86)	1.88 (1.01-3.52)
T3	106/103	1.30 (0.87-1.94)	1.63 (0.92-2.89)	1.39 (0.72-2.67)
P		0.159	< 0.001	-
Alcoholic beverage
T1	90/103	1.00	1.00	1.00
T2	107/101	1.20 (0.81-1.77)	1.05 (0.63-1.75)	1.10 (0.63-1.92)
T3	111/104	1.19 (0.83-1.72)	0.82 (0.50-1.36)	0.75 (0.42-1.32)
P		0.558	< 0.001	-

¹Food groups consumption was categorized into tertiles according to the distribution in controls, and by sexes for food groups with significant differences according to sex; Tertiles of food groups: Red and processed meat, T₁ < 47.7, T₂ 47.7-78.5, T₃ > 78.5; Total fish, T₁ < 42.8, T₂ 42.8-67.2, T₃ > 67.2; eggs, T₁ < 15.7, T₂ 15.7-23.5, T₃ > 23.5; Milk/dairy products, T₁ < 72.0, T₂ 72.0-232.1, T₃ > 232.1; Fat, T₁ < 30.8, T₂ 30.8-34.8, T₃ > 34.8; Nuts, T₁ < 2.9, T₂ 2.9-12.8, T₃ > 12.8; Sweets and added sugar, T₁ < 50.1, T₂ 50.1-117.3, T₃ > 117.3; Tertiles of food groups for men: Fiber-containing foods, T₁ < 424.3, T₂ 424.3-617.8, T₃ > 617.8; Alcoholic beverages, T₁ < 66.7, T₂ 66.7-137.2, T₃ > 137.2; Tertiles of food groups for women: Fiber-containing foods, T₁ < 537.9, T₂ 537.9-723.6, T₃ > 723.6; T₁ < 8.3; T₂ 8.3-85.7; T₃ > 85.7.

²Model I, analyses were performed using crude conditional logistic regression, without taking into account confounding factors.

³Model II, analyses were performed using conditional logistic regression analysis adjusted for age (50-59 years old, 60-69 years old), sex, body mass index (underweight/normal weight, overweight/obesity), energy intake (kcal/d), physical exercise level (< 15 min/d of cycling/sports, ≥ 15 min/d), smoking status and intensity of smoking (never; past: quit smoking ≥ 11 years ago, quit < 11 years ago; Smoker: ≤ 15 cigarettes/d, > 15 cigarettes/d), Deprivation Index (quintile 1-3,quintile 4-5) and Predictive Risk Modelling (level 1-2, level 3-4), including food groups separately; participants with missing data for the confounding variables were included as a separate category for these variables.

⁴Model III, model II including all the mean food groups. CI: Confidence interval; OR: Odd ratio; T: Tertile.

Table 5 Association between food subgroup intakes and colorectal cancer risk

Food subgroup intakes1	No., case/control	Model I2	Model II3	Model III4
		OR (95%CI)	OR (95%CI)	OR (95%CI)
Red meat
T1	88/101	1.00	1.00	1.00
T2	103/98	1.20 (0.81-1.79)	1.38 (0.82-2.34)	1.10 (0.62-1.96)
T3	117/109	1.22 (0.84-1.78)	1.41 (0.87-2.30)	1.17 (0.67-2.03)
P		0.534	< 0.001	-
Processed meat
T1	102/103	1.00	1.00	1.00
T2	82/99	0.84 (0.57-1.24)	0.62 (0.36-1.07)	0.67 (0.38-1.18)
T3	124/106	1.21 (0.83-1.77)	1.54 (0.91-2.60)	1.54 (0.88-2.70)
P		0.206	< 0.001	-
White fish
T1	95/105	1.00	1.00	1.00
T2	77/103	0.82 (0.53-1.25)	0.97 (0.56-1.68)	0.96 (0.36-2.53)
T3	136/105	1.49 (1.01-2.20)	1.06 (0.62-1.79)	1.29 (0.74-2.25)
P		0.008	< 0.001	-
Fatty fish
T1	119/110	1.00	1.00	1.00
T2	105/102	1.05 (0.71-1.55)	0.93 (0.56-1.55)	0.89 (0.43-1.69)
T3	74/96	0.72 (0.49-1.08)	0.50 (0.29-0.87)	0.53 (0.27-0.99)
P		0.145	< 0.001	-
Fresh cheese
T1	150/153	1.00	1.00	1.00
T2	224/33	0.64 (0.32-1.28)	1.06 (0.44-2.55)	1.11 (0.66-1.87)
T3	134/122	1.11 (0.80-1.55)	1.10 (0.70-1.72)	0.92 (0.58-1.46)
P		0.272	< 0.001	-
Other cheeses
T1	96/116	1.00	1.00	1.00
T2	71/75	1.16 (0.76-1.77)	1.51 (0.86-2.63)	1.83 (1.15-2.89)
T3	141/117	1.46 (1.01-2.12)	1.85 (1.12-3.05)	1.87 (1.11-3.16)
P		0.112	< 0.001	-
Fruits
T1	109/99	1.00	1.00	1.00
T2	98/110	0.82 (0.56-1.19)	1.08 (0.63-1.85)	1.03 (0.58-1.83)
T3	101/99	0.92 (0.62-1.37)	0.70 (0.40-1.22)	0.68 (0.37-1.26)
P		0.567	< 0.001	-
Vegetables
T1	97/102	1.00	1.00	1.00
T2	111/103	1.14 (0.76-1.71)	0.98 (0.55-1.73)	1.10 (0.60-2.04)
T3	100/103	1.03 (0.68-1.57)	0.94 (0.52-1.70)	1.10 (0.58-2.11)
P		0.789	< 0.001	-
Whole grains
T1	144/128	1.00	1.00	1.00
T2	83/77	0.92 (0.62-1.38)	0.86 (0.52-1.42)	0.98 (0.58-1.65)
T3	81/103	0.68 (0.46-1.01)	0.62 (0.37-1.06)	0.62 (0.39-0.98)
P		0.135	< 0.001

¹Food groups consumption was categorized into tertiles according to the distribution in controls, and by sexes for food groups with significant differences according to sex; Tertiles of food groups: Red meat, T₁ < 33.5, T₂ 33.5-54.9, T₃ > 54.9; Processed meat, T₁ < 11.6, T₂ 11.6-22.8, T₃ > 22.8; non-cheese dairy, T₁ < 225.0, T₂ 225.0-325.0, T₃ > 325.0; Cheese, T₁ < 7.5, T₂ 7.5-20.0, T₃ > 20.0; Vegetables, T₁ < 152.9, T₂ 152.9-237.2, T₃ > 237.2;Tertiles of food groups for men: Fruits, T₁ < 207.5, T₂ 207.5-392.9, T₃ > 392.9; Whole grains, T₁ < 1.0, T₂ 1.0-17.5, T₃ > 17.5; Tertiles of food groups for women: Fruits T₁ < 242.9, T₂ 242.9-425.0,: Whole grains, T₁ < 2.0, T₂ 2.0-30.0, T₃ > 30.0.

²Model I, analyses were performed using crude conditional logistic regression, without taking into account confounding factors.

³Model II, analyses were performed using conditional logistic regression analysis adjusted for age (50-59 years old, 60-69 years old), sex, body mass index (underweight/normal weight, overweight/obesity), energy intake (kcal/d), physical exercise level (< 15 min/d of cycling/sports, ≥ 15 min/d), smoking status and intensity of smoking (never; past: quit smoking ≥ 11 years ago, quit < 11 years ago; Smoker: ≤ 15 cigarettes/d, > 15 cigarettes/d), Deprivation Index (quintile 1-3, quintile 4-5) and Predictive Risk Modelling (level 1-2, level 3-4), including food groups separately; Participants with missing data for the confounding variables were included as a separate category for these variables.

⁴Model III, model II including all the mean food groups. CI: Confidence interval; OR: Odd ratio; T: Tertile.

Table 6 Diet quality indices in the sample studied

	Cases (n = 308)		Controls (n = 308)		P value
	mean	SD	mean	SD
HEISD components1
Meats	3.1	1.7	3.1	1.7	0.811
Processed meats	2.8	2.0	3.1	2.2	0.162
Legumes	8.6	2.1	8.5	2.3	0.716
Milk/Dairy	9.8	1.2	9.8	1.1	0.797
Fruits	9.1	1.8	9.1	1.9	0.464
Vegetables	8.9	1.7	8.9	1.6	0.816
Grains	9.9	0.9	9.9	1.9	0.862
Sweets	1.6	3.1	1.6	3.0	0.847
Soft-drink	8.8	2.5	8.7	2.6	0.583
Variety	8.0	1.7	8.0	1.7	0.646
Total HEISD	70.7	7.2	70.8	7.9	0.906
MDS components2
Red meats and processed meats	0.7	1.0	0.8	1.2	0.134
Poultry	2.9	1.2	2.9	1.2	0.335
Fish	3.8	1.1	3.8	1.2	0.771
Legumes	2.4	1.2	2.3	1.1	0.482
Full fat dairy	2.0	1.8	2.0	1.9	0.618
Vegetables	4.9	0.6	4.9	0.5	0.599
Fruits	4.6	1.0	4.6	1.0	0.726
Potatoes	2.2	1.5	2.4	1.5	0.054
Whole grains	2.0	2.2	2.3	2.3	0.044
Alcoholic beverages	4.9	0.4	4.9	0.4	0.729
Olive oil	4.9	0.6	4.8	0.8	0.446
Total MDS	35.3	4.5	36.0	4.3	0.027

¹Each component can contribute 10 points to the total score and the theoretical range is 0–100.

²Each component can contribute five points to the total score and the theoretical range is 0–55. HEISD: Healthy Eating Index for Spanish Diet; MDS: Med Diet Score; SD: Standard deviation.