Table 2.

Association Between Diet Composite Dietary Antioxidant Index (CDAI) and Risk of Colorectal, Colon and Rectal Cancer in the Singapore Chinese Health Study, 1993–2015

CDAI in quartile	Colorectal cancer			Colon Cancer		Rectal Cancer
	Person-year	Cases	HRa (95% CI)	Cases	HRa (95% CI)	Cases	HRa (95% CI)
Overall
Q1 (−13.3, −4.9)	258,240	582	1.00	372	1.00	210	1.00
Q2 (−4.9, −2.3)	268,428	545	0.94 (0.83–1.07)	354	0.97 (0.83–1.14)	191	0.89 (0.72–1.10)
Q3 (−2.3, 1.0)	271,862	507	0.86 (0.75–1.00)	325	0.89 (0.74–1.06)	182	0.82 (0.65–1.05)
Q4 (1.0, 58.6)	275,831	506	0.80 (0.66–0.98)	304	0.77 (0.60–1.00)	202	0.85 (0.61–1.17)
Ptrend			0.02		0.05		0.21
Continuous scale (per SD increase)			0.92 (0.83–1.02)		0.87 (0.76–0.99)		1.02 (0.87–1.19)
Men
Q1 (−13.0, −4.9)	75,239	215	1.00	120	1.00	95	1.00
Q2 (−4.9, −2.3)	99,408	261	0.99 (0.82–1.20)	149	1.00 (0.78–1.29)	112	0.98 (0.73–1.31)
Q3 (−2.3, 1.0)	125,041	292	0.94 (0.76–1.15)	183	1.02 (0.78–1.33)	109	0.83 (0.60–1.15)
Q4 (1.0, 58.6)	154,817	347	0.93 (0.71–1.21)	204	0.92 (0.65–1.30)	143	0.95 (0.63–1.45)
Ptrend			0.50		0.72		0.56
Continuous scale (per SD increase)			0.98 (0.85–1.12)		0.87 (0.72–1.04)		1.16 (0.94–1.42)
Women
Q1 (−13.3, −4.9)	183,001	367	1.00	252	1.00	115	1.00
Q2 (−4.9, −2.3)	169,020	284	0.89 (0.75–1.06)	205	0.96 (0.78–1.18)	79	0.75 (0.55–1.03)
Q3 (−2.3, 1.0)	146,821	215	0.78 (0.63–0.97)	142	0.78 (0.60–1.02)	73	0.79 (0.54–1.15)
Q4 (1.0, 55.1)	121,014	159	0.66 (0.48–0.90)	100	0.64 (0.43–0.94)	59	0.70 (0.41–1.18)
Ptrend			0.007		0.02		0.19
Continuous scale (per SD increase)			0.86 (0.74–1.00)		0.86 (0.72–1.03)		0.86 (0.67–1.11)
Pheterogeneity			0.41		0.14		0.50

^aAdjusted for age, sex, dialect, year of interview, education level, BMI levels (<18.5, 18.5–<23.0, 23.0–<27.0, ≥27.0), smoking status, alcohol consumption, history of type 2 diabetes, physical activity, family history of colorectal cancer, and total energy intake for total subjects.