Table 5. The relative frequency and OR (95% CI) of breast cancer risk in association with Allium vegetables between cases and controls only among consumers.
| Variable | Case (n = 208) No. (%) |
Control (n = 237) No. (%) |
p-value | OR (95% CI)* | Adjusted OR (95% CI)† |
|---|---|---|---|---|---|
| Total onion (g/day) | 0.072 | ||||
| < 26.7 | 60 (25.6) | 74 (33) | 1 | 1 | |
| 26.7–75.0 | 76 (32.5) | 78 (34.8) | 1.20 (0.70–1.90) | 1.32 (0.78–2.22) | |
| > 75.0 | 98 (41.9) | 72 (32.2) | 1.67 (1.06–2.65)‡ | 0.72 (0.44–1.19) | |
| p for trend | 0.998 | 0.904 | |||
| Raw onion (g/day) | 0.529 | ||||
| < 4.4 | 48 (27.8) | 64 (33.2) | 1 | 1 | |
| 4.4–10.7 | 35 (20.2) | 37 (19.2) | 1.30 (0.70–2.30) | 1.43 (0.67–3.04) | |
| > 10.7 | 90 (52.0) | 92 (47.6) | 1.30 (0.81–2.09) | 0.89 (0.53–1.50) | |
| p for trend | 0.485 | 0.383 | |||
| Cooked onion (g/day) | 0.025 | ||||
| < 42.8 | 43 (22.6) | 45 (30.6) | 1 | 1 | |
| 42.8–75.0 | 128 (67.4) | 78 (53.1) | 1.71 (1.03–2.84)‡ | 1.03 (0.16–6.35) | |
| > 75.0 | 19 (10.0) | 24 (16.3) | 0.8 (0.40–1.70) | 0.60 (0.35–1.03) | |
| p for trend | 0.306 | 0.252 | |||
| Garlic (g/day) | 0.404 | ||||
| < 0.2 | 65 (31.5) | 54 (30.9) | 1 | 1 | |
| 0.2–0.9 | 85 (41.3) | 63 (36.0) | 1.10 (0.70–1.80) | 1.01 (0.57–1.76) | |
| > 0.9 | 56 (27.2) | 58 (33.1) | 0.80 (0.50–1.30) | 0.41 (0.20–0.83)‡ | |
| p for trend | 0.333 | 0.715 | |||
| Leek (g/day) | 0.232 | ||||
| < 1.4 | 60 (28.8) | 56 (23.6) | 1 | 1 | |
| 1.4–3.6 | 88 (42.4) | 96 (40.5) | 0.80 (0.50–1.40) | 0.64 (0.40–1.04) | |
| > 3.6 | 60 (28.8) | 85 (35.9) | 0.65 (0.40–1.07) | 0.28 (0.15–0.51)‡ | |
| p for trend | < 0.001 | 0.519 |
OR=odds ratio; CI=confidence interval.
*Unconditional logistic regression analysis was also performed to assess the risk breast development through exposure to either independent variables, i.e., the condition of prebiotic food usage (dichotomous variable) or tertile of usage; †Unconditional multivariate logistic regression analysis adjusted for confounders included age (≤48, >48 yr), menopause (yes or no), total calorie intake (≤2,148, >2,148 kcal/day), dietary fat (≤104, >104 g/day), dietary fiber (≤17, >17 g/day), and body mass index (≤24.9, 25-29.9, and >30 kg/m2); ‡Statistically significant (p<0.05).