TABLE 2.
HR and 95% CIs for the associations between plant-based diet index and prostate cancer risk in 47,239 men from the Health Professionals Follow-Up Study (1986–2014)1
| Q 1 | Q 2 | Q 3 | Q 4 | Q 5 | P-trend | |
|---|---|---|---|---|---|---|
| Plant-based diet index | ||||||
| Total prostate cancer | ||||||
| Cases, n | 1178 | 1383 | 1371 | 1384 | 1339 | |
| Age adjusted | 1 [Reference] | 1.12 (1.04, 1.21) | 1.08 (1.00, 1.17) | 1.07 (0.99, 1.15) | 1.03 (0.95, 1.11) | 0.99 |
| Multivariable adjusted | 1 [Reference] | 1.08 (1.00, 1.17) | 1.03 (0.95, 1.12) | 1.01 (0.94, 1.10) | 0.97 (0.90, 1.05) | 0.17 |
| Localized prostate cancer2 | ||||||
| Cases, n | 793 | 970 | 944 | 981 | 885 | |
| Age adjusted | 1 [Reference] | 1.17 (1.06, 1.29) | 1.11 (1.01, 1.22) | 1.14 (1.03, 1.25) | 1.04 (0.95, 1.15) | 0.64 |
| Multivariable adjusted | 1 [Reference] | 1.11 (1.01, 1.22) | 1.03 (0.94, 1.14) | 1.05 (0.95, 1.16) | 0.96 (0.87, 1.06) | 0.18 |
| Advanced prostate cancer2 | ||||||
| Cases, n | 102 | 101 | 122 | 92 | 98 | |
| Age adjusted | 1 [Reference] | 0.96 (0.72, 1.26) | 1.13 (0.86, 1.47) | 0.84 (0.63, 1.11) | 0.79 (0.60, 1.05) | 0.07 |
| Multivariable adjusted | 1 [Reference] | 0.94 (0.71, 1.24) | 1.12 (0.86, 1.46) | 0.83 (0.62, 1.10) | 0.78 (0.59, 1.04) | 0.06 |
| Lethal prostate cancer2 | ||||||
| Cases, n | 190 | 187 | 187 | 192 | 200 | |
| Age adjusted | 1 [Reference] | 0.91 (0.74, 1.12) | 0.88 (0.72, 1.08) | 0.86 (0.70, 1.06) | 0.81 (0.66, 0.99) | 0.04 |
| Multivariable adjusted | 1 [Reference] | 0.92 (0.75, 1.12) | 0.90 (0.73, 1.11) | 0.88 (0.71, 1.08) | 0.83 (0.67, 1.02) | 0.07 |
| Fatal prostate cancer2 | ||||||
| Cases, n | 167 | 160 | 157 | 152 | 170 | |
| Age adjusted | 1 [Reference] | 0.89 (0.71, 1.11) | 0.83 (0.67, 1.04) | 0.77 (0.62, 0.97) | 0.78 (0.63, 0.97) | 0.01 |
| Multivariable adjusted | 1 [Reference] | 0.89 (0.72, 1.11) | 0.86 (0.69, 1.08) | 0.80 (0.64, 1.00) | 0.81 (0.64, 1.01) | 0.04 |
| Healthful plant-based diet index | ||||||
| Total prostate cancer | ||||||
| Cases, n | 1173 | 1263 | 1453 | 1356 | 1410 | |
| Age adjusted | 1 [Reference] | 0.98 (0.90, 1.06) | 1.08 (1.00, 1.17) | 0.96 (0.89, 1.04) | 0.97 (0.90, 1.05) | 0.36 |
| Multivariable adjusted | 1 [Reference] | 0.96 (0.88, 1.04) | 1.05 (0.97, 1.14) | 0.93 (0.86, 1.01) | 0.95 (0.87, 1.02) | 0.11 |
| Localized prostate cancer2 | ||||||
| Cases, n | 822 | 886 | 1019 | 902 | 944 | |
| Age adjusted | 1 [Reference] | 0.98 (0.89, 1.08) | 1.09 (0.99, 1.20) | 0.94 (0.85, 1.03) | 0.97 (0.88, 1.06) | 0.29 |
| Multivariable adjusted | 1 [Reference] | 0.95 (0.86, 1.05) | 1.04 (0.95, 1.14) | 0.88 (0.80, 0.97) | 0.91 (0.83, 1.01) | 0.02 |
| Advanced prostate cancer2 | ||||||
| Cases, n | 89 | 100 | 97 | 121 | 108 | |
| Age adjusted | 1 [Reference] | 1.07 (0.80, 1.43) | 0.98 (0.74, 1.32) | 1.14 (0.86, 1.50) | 0.90 (0.68, 1.20) | 0.57 |
| Multivariable adjusted | 1 [Reference] | 1.07 (0.80, 1.42) | 0.99 (0.74, 1.33) | 1.15 (0.87, 1.52) | 0.93 (0.70, 1.25) | 0.75 |
| Lethal prostate cancer2 | ||||||
| Cases, n | 151 | 176 | 216 | 195 | 218 | |
| Age adjusted | 1 [Reference] | 1.01 (0.81, 1.26) | 1.17 (0.95, 1.44) | 0.94 (0.76, 1.17) | 0.95 (0.77, 1.18) | 0.41 |
| Multivariable adjusted | 1 [Reference] | 1.01 (0.81, 1.26) | 1.18 (0.95, 1.46) | 0.96 (0.77, 1.19) | 0.98 (0.79, 1.21) | 0.60 |
| Fatal prostate cancer2 | ||||||
| Cases, n | 136 | 140 | 185 | 164 | 181 | |
| Age adjusted | 1 [Reference] | 0.88 (0.70, 1.12) | 1.10 (0.88, 1.38) | 0.88 (0.70, 1.10) | 0.87 (0.69, 1.09) | 0.21 |
| Multivariable adjusted | 1 [Reference] | 0.89 (0.70, 1.13) | 1.12 (0.89, 1.40) | 0.89 (0.71, 1.13) | 0.89 (0.71, 1.13) | 0.35 |
1Values are presented as HRs (95% Cis) unless otherwise indicated. Diet indices were adjusted for total energy intake using the residual method. Age-adjusted Cox proportional hazards models stratified by age and time period. Multivariable-adjusted Cox proportional hazards models stratified by age and time period, and adjusted for race (white, nonwhite), height (in; ≤68, >68–70, >70–72, >72), BMI (≤18.5, 18.5–<25, 25–<30, ≥30), BMI at age 21 (kg/m2; ≤20, 21–<23, 23–<25, ≥25), smoking status (never, former, current), family history of prostate cancer (yes, no), PSA test in previous cycle (yes, no), PSA testing in >50% of previous cycles (yes, no), multivitamin use (yes, no), vitamin E supplement use (yes/no), alcohol intake (g/d; quintiles), physical activity (METs-h/wk; quintiles), aspirin use (yes, no), anti-cholesterol medication (yes, no), and diabetes (yes, no). P values for linear trend calculated by assigning the median score for each quintile to all participants in the quintile. MET, metabolic equivalent of task; PSA, prostate-specific antigen; Q, quintile.
2Localized prostate cancer: stage T1/T2 and N0, M0 at diagnosis; advanced prostate cancer: stage T3b/T4/N1/M1 at diagnosis is lethal prostate cancer: prostate cancer death or distant metastasis; fatal prostate cancer: prostate cancer death.