Table 2.
Intake of fiber and sources of fiber during adolescence and relative risk (95% confidence interval) of proliferative BBD in NHSII
| Exposures | Quintile of energy-adjusted fiber intake |
P trend | ||||
|---|---|---|---|---|---|---|
| 1 (low) | 2 | 3 | 4 | 5 (high) | ||
| Fiber | ||||||
| Intake (g/day)a | 15.1 | 18.0 | 20.3 | 22.8 | 27.5 | |
| No. of combined BBD casesb/pysc | 157/51815 | 147/51610 | 139/52007 | 127/51951 | 112/52444 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.96 (0.76, 1.20) | 0.91 (0.72, 1.14) | 0.83 (0.66, 1.06) | 0.73 (0.57, 0.93) | <0.01 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 0.96 (0.76, 1.20) | 0.91 (0.73, 1.15) | 0.85 (0.67, 1.07) | 0.75 (0.59, 0.96) | 0.01 |
| Additional adjustment for total nutsd | 1.00 (ref) | 0.98 (0.78, 1.22) | 0.94 (0.74, 1.18) | 0.88 (0.69, 1.12) | 0.80 (0.62, 1.02) | 0.05 |
| No. of prospective BBD casese/pysc | 37/13824 | 29/13817 | 28/13752 | 23/13744 | 25/13879 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.78 (0.48, 1.28) | 0.75 (0.46, 1.24) | 0.61 (0.36, 1.03) | 0.61 (0.37, 1.03) | 0.05 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 0.77 (0.47, 1.27) | 0.77 (0.47, 1.26) | 0.62 (0.36, 1.05) | 0.61 (0.36, 1.03) | 0.05 |
| Additional adjustment for total nutsf | 1.00 (ref) | 0.80 (0.49, 1.32) | 0.81 (0.49, 1.34) | 0.67 (0.39, 1.14) | 0.66 (0.39, 1.13) | 0.11 |
| Fiber from fruits | ||||||
| Intake (g/day)a | 1.7 | 2.9 | 4.0 | 5.3 | 7.6 | |
| No. of combined BBD casesb/pysc | 154/53746 | 139/53143 | 138/52007 | 125/49759 | 126/51173 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.90 (0.71, 1.13) | 0.90 (0.72, 1.14) | 0.87 (0.68, 1.10) | 0.85 (0.67, 1.08) | 0.20 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 0.91 (0.72, 1.14) | 0.92 (0.73, 1.16) | 0.90 (0.71, 1.14) | 0.89 (0.70, 1.13) | 0.38 |
| No. of prospective BBD casese/pysc | 33/14270 | 26/14078 | 28/13746 | 29/13191 | 26/13731 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.82 (0.49, 1.38) | 0.83 (0.50, 1.38) | 0.91 (0.55, 1.51) | 0.76 (0.45, 1.28) | 0.42 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 0.83 (0.49, 1.39) | 0.84 (0.50, 1.40) | 0.95 (0.57, 1.59) | 0.77 (0.45, 1.30) | 0.47 |
| Fiber from vegetables | ||||||
| Intake (g/day)a | 3.3 | 4.8 | 6.0 | 7.5 | 10.5 | |
| No. of combined BBD casesb/pysc | 158/55760 | 136/50795 | 136/50163 | 123/52946 | 129/50163 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.94 (0.74, 1.18) | 0.93 (0.74, 1.17) | 0.79 (0.62, 1.00) | 0.88 (0.69, 1.11) | 0.16 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 0.95 (0.76, 1.20) | 0.94 (0.75, 1.19) | 0.81 (0.64, 1.02) | 0.91 (0.72, 1.15) | 0.28 |
| No. of prospective BBD casese/pysc | 38/13912 | 29/14411 | 23/13206 | 25/14135 | 27/13353 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.75 (0.46, 1.22) | 0.64 (0.38, 1.08) | 0.63 (0.38, 1.05) | 0.73 (0.44, 1.20) | 0.21 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 0.76 (0.46, 1.24) | 0.62 (0.37, 1.05) | 0.64 (0.38, 1.07) | 0.73 (0.44, 1.21) | 0.22 |
| Fiber from cruciferous vegetables | ||||||
| Intake (g/day)a | 0.1 | 0.3 | 0.6 | 0.8 | 1.3 | |
| No. of combined BBD casesb/pysc | 168/62316 | 114/43807 | 151/51617 | 127/52170 | 122/49918 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.95 (0.75, 1.21) | 1.08 (0.86, 1.34) | 0.90 (0.71, 1.13) | 0.90 (0.71, 1.14) | 0.34 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 0.96 (0.75, 1.21) | 1.09 (0.87, 1.37) | 0.91 (0.72, 1.15) | 0.91 (0.72, 1.15) | 0.42 |
| No. of prospective BBD casese/pysc | 39/16518 | 20/11630 | 30/13644 | 21/13831 | 32/13394 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.70 (0.41, 1.21) | 0.92 (0.57, 1.49) | 0.62 (0.36, 1.05) | 0.98 (0.61, 1.58) | 0.98 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 0.68 (0.40, 1.18) | 0.94 (0.58, 1.53) | 0.60 (0.35, 1.04) | 0.98 (0.61, 1.59) | 0.97 |
| Fiber from legumes | ||||||
| Intake (g/day)a | 1.1 | 1.8 | 2.3 | 3.1 | 4.6 | |
| No. of combined BBD casesb/pysc | 147/53247 | 151/53585 | 130/50295 | 124/52415 | 130/50286 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.99 (0.79, 1.24) | 0.90 (0.71, 1.14) | 0.81 (0.63, 1.03) | 0.90 (0.71, 1.14) | 0.19 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 0.99 (0.79, 1.24) | 0.91 (0.72, 1.16) | 0.81 (0.64, 1.03) | 0.91 (0.72, 1.16) | 0.26 |
| No. of prospective BBD casese/pysc | 33/14197 | 35/14162 | 24/13329 | 23/13967 | 27/13361 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 1.03 (0.64, 1.66) | 0.76 (0.45, 1.30) | 0.66 (0.39, 1.14) | 0.83 (0.49, 1.40) | 0.27 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 1.00 (0.62, 1.62) | 0.75 (0.44, 1.28) | 0.64 (0.37, 1.10) | 0.81 (0.48, 1.37) | 0.24 |
| Fiber from cereal | ||||||
| Intake (g/day)a | 3.6 | 4.7 | 5.5 | 6.4 | 8.4 | |
| No. of combined BBD casesb/pysc | 158/55068 | 158/54091 | 123/47585 | 126/51659 | 117/51425 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 1.06 (0.85, 1.32) | 0.95 (0.75, 1.20) | 0.89 (0.70, 1.13) | 0.85 (0.67, 1.09) | 0.09 |
| Multivariate HR (95% CI)d | 1.00 (ref) | 1.07 (0.86, 1.34) | 0.97 (0.76, 1.23) | 0.91 (0.72, 1.15) | 0.88 (0.69, 1.12) | 0.14 |
| No. of prospective BBD casese/pysc | 27/14667 | 32/14278 | 33/12676 | 28/13681 | 22/13715 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 1.19 (0.71, 1.99) | 1.36 (0.81, 2.28) | 1.08 (0.63, 1.84) | 0.84 (0.47, 1.49) | 0.38 |
| Multivariate HR (95% CI)f | 1.00 (ref) | 1.17 (0.69, 1.97) | 1.35 (0.80, 2.27) | 1.06 (0.62, 1.81) | 0.85 (0.48, 1.51) | 0.41 |
Median fiber intake of each quintile, adjusted for total energy intake using the residual method.
682 cases of proliferative BBD (with or without atypia) were diagnosed during the follow-up period 1991–2001.
pys: person-years.
The multivariate models are adjusted for age in months, time period (5 periods), total energy intake (quintiles), age at menarche (<12, 12, 13, or ≥14 years), menopausal status (premenopausal, postmenopausal, or uncertain), average body size between ages 5 and 10 (somatotype pictogram 1, 1.5–2, 2.5–3, 3.5–4.5, or ≥5), family history of breast cancer in mother or sister(s) (yes vs. no), alcohol intake between ages 18 and 22 years (0, <5, 5–14, or ≥15 grams/day), multivitamin use between ages 13 and 18 years (yes vs. no), recency and duration of OC use (never, past <4 years, past ≥4 years, current <4 years, or current ≥4 years), and parity and age at first birth (nulliparous; 1–2 pregnancies, age at first birth <25 years; 1–2 pregnancies, age at first birth 25–29 years; 1–2 pregnancies, age at first birth ≥30 years; ≥3 pregnancies, age at first birth <25 years; ≥3 pregnancies, age at first birth 25–29 years; or ≥3 pregnancies, age at first birth ≥30 years).
142 cases of proliferative BBD (with or without atypia) were diagnosed during the follow-up period 1998–2001.
The multivariate models are adjusted for age in months, time period (2 periods), total energy intake (quintiles), age at menarche (<12, 12, 13, or ≥ 14 years), menopausal status (premenopausal, postmenopausal, or uncertain), average body size between ages 5 and 10 (somatotype pictogram 1, 1.5–2, 2.5–3, 3.5–4.5, ≥5), history of breast cancer in mother or sister(s) (yes vs. no), alcohol intake between ages 18 and 22 (0, <5, 5–14, or ≥15 grams/day), multivitamin use between ages 13 and 18 (yes vs. no), recency and duration of OC use (never, past <4 years, past ≥4 years, or current), and parity and age at first birth (nulliparous; 1–2 pregnancies, age at first birth <25 years; 1–2 pregnancies, age at first birth 25–29 years; 1–2 pregnancies, age at first birth ≥30 years; ≥3 pregnancies, age at first birth <25 years; or ≥3 pregnancies, age at first birth ≥25 years).