Dietary vitamins E and C and prostate cancer risk

Figures & data

Table I.  Distribution of 1 294 cases of prostate cancer and 1 451 controls according to age and selected covariates. Italy, 1991–2002^a.

	No. (%)
	Prostate cancer	Controls No. (%)
Age (years)
< 55	63 (4.9)	133 (9.1)
55–59	156 (12.1)	298 (20.5)
60–64	310 (24.0)	359 (24.7)
65–69	419 (32.4)	364 (25.1)
70–74	346 (26.7)	297 (20.5)
Body Mass Index (kg/m^2)
< 24.22	301 (23.3)	368 (25.4)
24.22–26.17	346 (26.8)	356 (24.6)
26.18–28.40	324 (25.1)	365 (25.2)
≥ 28.41	319 (24.7)	358 (24.7)
Education (years)
< 7	636 (49.6)	844 (58.5)
7–11	384 (29.9)	407 (28.2)
≥ 12	263 (20.5)	192 (13.3)
Occupational physical activity at age 30
Very active	518 (40.2)	684 (47.1)
Moderately active	335 (26.0)	393 (27.1)
Inactive	437 (33.9)	374 (25.8)
Family history of prostate cancer^b
No	1204 (93.0)	1423 (98.1)
Yes	90 (7.0)	28 (1.9)
Alcohol consumption
Never drinker	71 (5.5)	72 (5.0)
Ex drinker	93 (7.2)	128 (8.8)
Current drinker	1130 (87.3)	1248 (86.2)
Smoking
Never	370 (28.6)	344 (23.7)
Current/former	924 (71.4)	1107 (78.3)
Total energy intake (Kcal/day)
< 2487.07	618 (47.8)	754 (52.0)
≥ 2487.07	676 (52.2)	697 (48.0)

^aThe sum does not add up to the total because of some missing values.

^bFirst-degree relatives.

Table II.  Odds ratios (OR)^a of prostate cancer, and corresponding 95% confidence intervals (CI), according to intake of vitamin E and C. Italy, 1991–2002.

			Tertile, OR (95% CI)
Nutrient	Mean^b	Standard deviation	1(lowest)^c	2	3	X^2 trend (P value)	OR (continuous)^d
Vitamin E (mg)^e	15.3	6.5	1	0.87 (0.69–1.05)	0.78 (0.58–0.96)	5.03 (0.02)	0.82 (0.74–1.00)
Vitamin C (mg)^f	128.5	73.1	1	0.92 (0.72–1.11)	0.86 (0.65–1.08)	2.86 (0.09)	0.88 (0.78–1.07)

^aEstimates from multiple logistic regression models including terms for age, study center, period of interview, education, body mass index, alcohol intake, smoking habits, family history of prostate cancer and total energy intake, according to the residual model.

^bAmong controls, per day;

^c Reference category;

^dOR relative to 1 standard deviation among controls;

^eVitamin E cut offs: 12.3, and 16.7;

^fVitamin C cut offs: 95.8, and 139.9.

Table III.  Odds ratios (OR)^a,b of prostate cancer, and corresponding 95% confidence intervals (CI), according to intake of vitamin E and C, in strata of age, body mass index (BMI), and family history of prostate cancer. Italy, 1991–2002.

	Age (years)		BMI (kg/m^2)		Family history of prostate cancer^c
Nutrient	<60	≥60	<25	≥25	No	Yes
Vitamin E^d	0.74 (0.46–0.98)	0.79 (0.48–1.04)	0.76 (0.48–1.03)	0.79 (0.54–1.06)	0.78 (0.57–0.98)	0.64 (0.11–2.73)
Vitamin C^e	0.83 (0.47–1.16)	0.88 (0.55–1.21)	0.84 (0.53–1.30)	0.86 (0.60–1.44)	0.87 (0.64–1.15)	0.63 (0.14–2.53)

^aEstimates from multiple logistic regression models including terms for age, study center, period of interview, education, body mass index, alcohol intake, smoking habits, family history of prostate cancer and total energy intake, when appropriate, according to the residual model. ^bORs of highest quintile of intake vs. lowest. ^cFirst-degree relatives. ^dp-value for interaction for age:0.74, BMI:0.81, and family history of prostate cancer:0.68. ^ep-value for interaction for age:0.84, BMI:0.87, and family history of prostate cancer:0.72.