Table 3.

Meat-related compounds and colorectal cancer in the NIH-AARP Diet and Health Study (n = 300,948)

Colorectal cancer (n = 2,719)Colon cancer (n = 1,995)Rectal cancer (n = 724)
CasesHR* (95% CI)CasesHR* (95% CI)CasesHR* (95% CI)
Total iron (median, mg/d)
    Q1 (10.8)6461.04831.01631.0
    Q2 (14.8)5780.91 (0.81–1.02)4250.89 (0.78–1.02)1530.96 (0.77–1.21)
    Q3 (21.5)5390.88 (0.78–0.99)3870.85 (0.74–0.97)1520.99 (0.79–1.24)
    Q4 (30.6)4960.81 (0.72–0.91)3680.80 (0.70–0.92)1280.85 (0.67–1.07)
    Q5 (36.1)4600.75 (0.66–0.86)3320.73 (0.62–0.84)1280.84 (0.65–1.08)
    Ptrend<0.001<0.0010.070
Dietary iron (median, mg/1,000 kcal)
    Q1 (5.9)6771.04831.01941.0
    Q2 (7.2)5370.82 (0.73–0.92)3970.84 (0.73–0.96)1400.76 (0.60–0.95)
    Q3 (8.2)5180.80 (0.70–0.90)3900.84 (0.72–0.96)1280.70 (0.55–0.88)
    Q4 (9.3)5090.79 (0.69–0.90)3740.81 (0.70–0.94)1350.73 (0.57–0.93)
    Q5 (11.4)4780.75 (0.65–0.87)3510.78 (0.66–0.92)1270.68 (0.52–0.90)
    Ptrend<0.0010.0090.017
Heme iron (median, μg/1,000 kcal)
    Q1 (48.1)4681.03471.01211.0
    Q2 (100.9)5081.00 (0.88–1.13)3780.99 (0.86–1.15)1301.01 (0.79–1.30)
    Q3 (150.3)5381.02 (0.90–1.16)3971.01 (0.87–1.17)1411.06 (0.82–1.36)
    Q4 (212.6)5771.07 (0.94–1.21)4211.04 (0.90–1.21)1561.13 (0.88–1.45)
    Q5 (335.8)6281.13 (0.99–1.29)4521.10 (0.94–1.28)1761.24 (0.96–1.60)
    Ptrend0.0220.1380.049
Nitrate from processed meats (median, μg/1,000 kcal)
    Q1 (23.9)4511.03411.01101.0
    Q2 (65.3)4700.96 (0.85–1.10)3440.93 (0.80–1.08)1261.08 (0.83–1.40)
    Q3 (109.6)5301.04 (0.91–1.18)3860.99 (0.86–1.16)1441.18 (0.91–1.52)
    Q4 (169.2)6091.13 (1.00–1.29)4391.08 (0.93–1.25)1701.31 (1.01–1.68)
    Q5 (289.2)6591.16 (1.02–1.32)4851.13 (0.97–1.32)1741.26 (0.97–1.63)
    Ptrend0.0010.0090.066
Nitrite from processed meats (median, μg/1,000 kcal)
    Q1 (11.9)4571.03441.01131.0
    Q2 (33.7)4880.99 (0.87–1.12)3590.96 (0.83–1.12)1291.07 (0.83–1.38)
    Q3 (59.7)5541.07 (0.94–1.21)3971.01 (0.88–1.18)1571.23 (0.96–1.58)
    Q4 (99.9)6031.12 (0.98–1.27)4411.09 (0.94–1.26)1621.21 (0.94–1.55)
    Q5 (194.1)6171.11 (0.97–1.25)4541.09 (0.94–1.26)1631.16 (0.90–1.50)
    Ptrend0.0550.0890.369
PhIP (median, ng/1,000 kcal)
    Q1 (2.1)5121.03821.01301.0
    Q2 (10.9)4980.90 (0.79–1.02)3570.87 (0.75–1.00)1411.00 (0.78–1.27)
    Q3 (24.7)5600.99 (0.87–1.12)4020.96 (0.83–1.10)1581.08 (0.85–1.36)
    Q4 (49.4)5911.04 (0.92–1.17)4341.03 (0.90–1.19)1571.06 (0.83–1.34)
    Q5 (123.6)5580.99 (0.87–1.12)4201.01 (0.87–1.16)1380.94 (0.73–1.20)
    Ptrend0.5070.2120.440
MeIQx (median, ng/1,000 kcal)
    Q1 (0.5)4821.03461.01361.0
    Q2 (2.4)5061.01 (0.89–1.15)3701.03 (0.89–1.20)1360.96 (0.76–1.22)
    Q3 (5.3)5120.99 (0.88–1.13)3650.99 (0.85–1.15)1471.00 (0.79–1.27)
    Q4 (10.3)5711.08 (0.95–1.22)4271.13 (0.98–1.31)1440.94 (0.74–1.20)
    Q5 (24.4)6481.19 (1.05–1.34)4871.26 (1.09–1.45)1611.01 (0.79–1.28)
    Ptrend<0.001<0.0010.852
DiMeIQx (median, ng/1,000 kcal)
    Q1 (0.0)9221.06651.02571.0
    Q2 (0.04)1051.02 (0.84–1.25)771.05 (0.83–1.33)280.95 (0.64–1.40)
    Q3 (0.19)4960.96 (0.86–1.07)3650.98 (0.86–1.11)1310.91 (0.73–1.12)
    Q4 (0.58)5671.06 (0.95–1.18)4121.07 (0.95–1.21)1551.03 (0.84–1.25)
    Q5 (1.74)6291.17 (1.05–1.29)4761.23 (1.10–1.39)1531.00 (0.81–1.22)
    Ptrend<0.001<0.0010.806
B(a)P (median, ng/1,000 kcal)
    Q1 (0.21)5511.04011.01501.0
    Q2 (1.50)5831.02 (0.91–1.14)4271.03 (0.90–1.18)1561.00 (0.80–1.25)
    Q3 (6.17)5310.96 (0.85–1.08)3970.99 (0.86–1.14)1340.88 (0.70–1.12)
    Q4 (16.83)4910.86 (0.76–0.97)3630.88 (0.76–1.01)1280.81 (0.64–1.02)
    Q5 (43.97)5630.96 (0.85–1.08)4070.96 (0.83–1.11)1560.95 (0.75–1.19)
    Ptrend0.2910.3220.694
Mutagenic activity (median, revertant colonies/1,000 kcal)
    Q1 (165)4801.03491.01311.0
    Q2 (601)5110.98 (0.86–1.11)3660.97 (0.83–1.12)1451.01 (0.79–1.28)
    Q3 (1152)5561.04 (0.92–1.18)4041.05 (0.91–1.21)1521.02 (0.80–1.30)
    Q4 (2042)5631.05 (0.93–1.19)4201.09 (0.94–1.26)1430.95 (0.74–1.21)
    Q5 (4349)6091.14 (1.01–1.29)4561.19 (1.03–1.38)1531.01 (0.79–1.29)
    Ptrend0.0100.0020.967
  • *Adjusted for gender, education (high school or less/unknown, post-high school/some college, college/postgraduate), BMI (<18.5, ≥18.5 to <25, ≥25 to <30, ≥30 to <35, ≥35, unknown), smoking (never smoker, former smoker who quit ≥10 y ago, former smoker who quit 1–9 y ago, current/those who quit <1 y ago, missing), and intake of total energy (kcal/d), fiber (g/1,000 kcal), and dietary calcium (mg/1,000 kcal).

  • Dietary iron residually energy adjusted plus iron from supplements.