Table 2.
The type and dose of whole grain intake and the relative risk of breast cancer in the included studies
| Study | Type of whole grain intake | Dose of whole grain intake (g/d) | Relative Risk(95%CI) |
|---|---|---|---|
| Farvid et al., 2016 [15] | whole grain foods | Q1: 5.6; Q2: 14; Q3: 19.6; Q4: 28; Q5: 42 | Q1: 1; Q2: 0.93 (0.83–1.03); Q3: 0.87 (0.77–0.97); Q4: 0.91 (0.81–1.02); Q5: 0.91 (0.81–1.03) |
| Mourouti et al., 2016 [16] | whole grain foods (including whole grain bread, whole grain cereals, oatmeal, whole wheat pasta, brown or wild rice) | No reported | Never/rarely: 1; 1–6 times/week: 0.68 (0.41, 1.09); > 7 times/week:0.49 (0.29, 0.82) |
| Tajaddini et al., 2015 [18] | whole-wheat bread (Sangak, Taftoon, Barbari, barley, corn flakes and sprouts) | < 1.0; 1.0–23.0; > 23.0 | < 1.0 g/d: 1; 1.0–23.0 g/d: 1.39(0.68–2.83); > 23.0 g/d: 0.61(0.37–0.99) |
| Yun et al., 2010 [17] | mixed brown rice | 0; 100; 350 | 0 g/d:1.0; 100 g/d: 0.90(0.47,1.71); 350 g/d: 0.42(0.20,0.87) Per 100 g/d: 0.76(0.61,0.95) |
| Egeberg et al., 2009 [23] | whole grain products (rye bread, whole grain bread and oatmeal) | ≤72; 72 to ≤112; 112 to ≤163; > 163 | ≤72 g/d: 1; 72 to ≤112 g/d: 0.98 (0.82–1.17); 112 to ≤163 g/d: 1.00 (0.85–1.19); > 163 g/d: 1.03 (0.85–1.24) Per each additional 50 g/day: 1.01(0.96–1.07) |
| Sonestedt et al.,2008 [19] | high-fibre bread (≥ 6% of fibre for soft bread, ≥10% for crisp bread and ≥ 10% for biscuits and rusks) | Q1: 0; Q2:9; Q3:19; Q4: 34; Q5: 65 | Q1: 1; Q2: 0.87 (0.67–1.13); Q3: 0.74 (0.56–0.97); Q4: 0.82 (0.63–1.07); Q5: 0.75 (0.57–0.98) |
| Adzersen et al., 2003 [20] | the whole-grain category all whole-grain bread and rice, rolled oats, muesli, and cornflakes. | Q1: < 18.3; Q2:18.3 ≤ 32.6; Q3: 32.6 ≤ 45.5;Q4:> 45.5 | Q1: 1; Q2: 0.96 (0.61,1.52); Q3:0.76 (0.47–1.24); Q4:0.57 (0.34–0.95) |
| Nicodemus et al., 2001 [22] | whole grains | Q1:0–3.5; Q2: 4–7; Q3: 7.5–10.5; Q4:11–18.5; Q5:19–108.5 (servings/week) | Q1: 1; Q2: 0.95 (0.76–1.2); Q3: 1.04 (0.84–1.3); Q4: 1.19 (0.96–1.5); Q5: 1.21 (0.96–1.5) |
| Chatenoud et al., 1998 [21] | whole grain food (essentially bread or pasta) | No reported | Low (no or rare consumption): 1; Intermediate (1–3 days/week): 0.9(0.8–1.0);High (> 3 days/week): 0.9(0.8–1.0) |
| Levi et al., 1993 [25] | whole-grain bread and pasta | No reported | Low: 1; Intermediate: 0.77(0.41–1.44); High: 0.63(0.35–1.15) |
| LaVecchia et al., 1987 [24] | whole-grain bread or pasta | No reported | Never: 1; Occasionally: 0.75(0.57–0.96); Frequently: 0.90(0.69–1.17) |
Q = quintiles or quartiles