Table 4.
Hazard ratios (95% confidence intervals) for colorectal cancer risk with plant-based diet indices by anatomic subsite in the Multiethnic Cohort Study, 1993–2017
| Right colon | Left colon | Rectum | P for heterogeneity | ||||
|---|---|---|---|---|---|---|---|
| Cases | HR (95% CI) a | Cases | HR (95% CI) a | Cases | HR (95% CI) a | ||
| Men | |||||||
| Overall plant-based diet index | |||||||
| Q1 | 185 | 1.00 (ref) | 149 | 1.00 (ref) | 140 | 1.00 (ref) | |
| Q2 | 244 | 0.96 (0.79–1.16) | 164 | 0.84 (0.67–1.06) | 159 | 0.87 (0.69–1.09) | |
| Q3 | 235 | 0.97 (0.79–1.18) | 178 | 0.99 (0.79–1.24) | 146 | 0.86 (0.68–1.09) | |
| Q4 | 198 | 0.92 (0.75–1.13) | 132 | 0.85 (0.67–1.08) | 137 | 0.94 (0.73–1.20) | |
| Q5 | 221 | 0.90 (0.73–1.10) | 107 | 0.62 (0.48–0.81) | 112 | 0.69 (0.53–0.89) | |
| P for trend | 0.27 | 0.002 | 0.02 | 0.005 | |||
| Healthful plant-based diet index | |||||||
| Q1 | 210 | 1.00 (ref) | 152 | 1.00 (ref) | 143 | 1.00 (ref) | |
| Q2 | 253 | 0.93 (0.77–1.12) | 177 | 0.94 (0.75–1.17) | 164 | 0.94 (0.75–1.18) | |
| Q3 | 211 | 0.90 (0.74–1.09) | 163 | 1.02 (0.81–1.27) | 149 | 1.01 (0.80–1.28) | |
| Q4 | 226 | 0.90 (0.74–1.09) | 122 | 0.72 (0.56–0.91) | 137 | 0.88 (0.70–1.12) | |
| Q5 | 183 | 0.81 (0.66–0.99) | 116 | 0.77 (0.60–0.99) | 101 | 0.74 (0.57–0.96) | |
| P for trend | 0.04 | 0.007 | 0.02 | 0.16 | |||
| Unhealthful plant-based diet index | |||||||
| Q1 | 221 | 1.00 (ref) | 147 | 1.00 (ref) | 112 | 1.00 (ref) | |
| Q2 | 267 | 0.96 (0.80–1.15) | 152 | 0.80 (0.64–1.00) | 159 | 1.07 (0.84–1.37) | |
| Q3 | 213 | 0.94 (0.78–1.14) | 151 | 0.95 (0.76–1.20) | 134 | 1.08 (0.84–1.39) | |
| Q4 | 170 | 0.91 (0.74–1.11) | 112 | 0.83 (0.65–1.07) | 131 | 1.23 (0.95–1.58) | |
| Q5 | 212 | 1.02 (0.84–1.24) | 168 | 1.04 (0.83–1.31) | 158 | 1.24 (0.97–1.59) | |
| P for trend | 0.98 | 0.60 | 0.05 | 0.048 | |||
| Women | |||||||
| Overall plant-based diet index | |||||||
| Q1 | 197 | 1.00 (ref) | 99 | 1.00 (ref) | 72 | 1.00 (ref) | |
| Q2 | 294 | 1.00 (0.84–1.20) | 142 | 0.98 (0.76–1.27) | 100 | 0.96 (0.71–1.31) | |
| Q3 | 272 | 0.96 (0.80–1.16) | 126 | 0.92 (0.71–1.21) | 116 | 1.18 (0.88–1.60) | |
| Q4 | 242 | 0.96 (0.79–1.17) | 113 | 0.94 (0.72–1.24) | 59 | 0.69 (0.48–0.98) | |
| Q5 | 265 | 1.01 (0.83–1.22) | 125 | 1.01 (0.77–1.33) | 89 | 1.00 (0.72–1.38) | |
| P for trend | 0.96 | 0.97 | 0.52 | 0.38 | |||
| Healthful plant-based diet index | |||||||
| Q1 | 227 | 1.00 (ref) | 129 | 1.00 (ref) | 82 | 1.00 (ref) | |
| Q2 | 290 | 1.04 (0.87–1.24) | 124 | 0.82 (0.64–1.05) | 101 | 1.03 (0.77–1.38) | |
| Q3 | 251 | 1.06 (0.89–1.27) | 117 | 0.93 (0.72–1.20) | 103 | 1.28 (0.95–1.72) | |
| Q4 | 255 | 0.96 (0.80–1.16) | 124 | 0.89 (0.69–1.15) | 74 | 0.83 (0.60–1.14) | |
| Q5 | 247 | 0.97 (0.81–1.17) | 111 | 0.84 (0.65–1.10) | 76 | 0.91 (0.66–1.25) | |
| P for trend | 0.59 | 0.36 | 0.30 | 0.27 | |||
| Unhealthful plant-based diet index | |||||||
| Q1 | 251 | 1.00 (ref) | 122 | 1.00 (ref) | 80 | 1.00 (ref) | |
| Q2 | 306 | 0.99 (0.83–1.16) | 141 | 0.91 (0.71–1.16) | 96 | 0.95 (0.70–1.28) | |
| Q3 | 264 | 1.02 (0.86–1.21) | 115 | 0.87 (0.67–1.12) | 83 | 0.96 (0.71–1.31) | |
| Q4 | 210 | 0.99 (0.83–1.19) | 96 | 0.87 (0.66–1.14) | 76 | 1.06 (0.78–1.46) | |
| Q5 | 239 | 0.99 (0.83–1.19) | 131 | 1.00 (0.78–1.28) | 101 | 1.19 (0.89–1.61) | |
| P for trend | 0.98 | 0.88 | 0.17 | 0.22 | |||
aModels were adjusted for age at cohort entry, race and ethnicity, family history of colorectal cancer, history of colorectal polyp, body mass index, pack-years of cigarette smoking, multivitamin use, nonsteroidal anti-inflammatory drug use, physical activity, menopausal hormone therapy use for women only, alcohol consumption, and total energy intake