Table 2.

Summary estimates of dietary flavonoids and stomach and colorectal cancer risk

	Combined					Colorectum					Stomach
				Heterogeneity					Heterogeneity					Heterogeneity
na	RR	95%CI	I2	Pb	n	RR	95%CI	I2	Pb	n	RR	95%CI	I2	Pb
Total flavonoids	11	1.00	0.91-1.11	15.0%	0.301	9	1.00	0.90-1.11	28.2%	0.194	2	1.07	0.70-1.61	0%	0.464
Cohort	9	1.05	0.93-1.18	0%	0.517	7	1.04	0.92-1.18	9.6%	0.355	2	-	-	-	-
Case-control	-	-	-	-	-	2	0.81	0.50-1.29	67.9%	0.078c	0
Female	-	-	-	-	-	3	0.93	0.84-1.04	0%	0.890	0
Male	5	1.05	0.96-1.15	0%	0.514	4	1.05	0.96-1.15	18.6%	0.298	1
Flavonols	7	0.71	0.63-0.80	10.7%	0.348	5	0.71	0.63-0.81	37.0%	0.175	2	0.68	0.46-0.99	0%	0.586
Case-control	6	0.70	0.62-0.79	0%	0.755	4	0.70	0.62-0.79	0%	0.510	2	-	-	-	-
Female	-	-	-	-	-	2	0.84	0.75-0.93	0%	0.361	0
Male	-	-	-	-	-	3	0.87	0.79-0.96	45.4%	0.160	0
Quercetin	8	0.81	0.68-0.97	44.1%	0.085c	4	0.90	0.80-1.03	42.2%	0.159	4	0.66	0.51-0.85	0%	0.472
Kaempferol	4	0.95	0.65-1.37	55.2%	0.082c	2	1.12	0.91-1.38	0%	0.979	2	0.73	0.31-1.71	71.8%	0.060c
Myricetin	4	1.15	0.87-1.51	0%	0.965	2	1.15	0.80-1.67	0%	0.607	2	1.13	0.75-1.71	0%	0.935
Flavones	6	0.84	0.74-0.96	44.8%	0.107	4	0.83	0.63-1.09	64.4%	0.038c	2	0.76	0.54-1.08	0%	0.635
Case-control	5	0.82	0.66-1.02	55.0%	0.064c	3	0.83	0.61-1.14	87.9%	0.016c	2	-	-	-	-
Female	-	-	-	-	-	2	0.94	0.84-1.04	0%	0.353	0
Male	-	-	-	-	-	3	0.92	0.84-1.02	0%	0.477	0
Flavanones	7	1.04	0.86-1.27	44.5%	0.094c	5	1.08	0.95-1.22	28.2%	0.234	2	0.72	0.49-1.07	38.3%	0.203
Case-control	6	1.05	0.85-1.30	53.3%	0.057c	4	1.08	0.95-1.23	46.4%	0.144	2	-	-	-	-
Female	-	-	-	-	-	2	1.01	0.89-1.14	0%	0.734	0
Male	-	-	-	-	-	3	0.99	0.89-1.11	0%	0.583	0
Hesperidin	3	1.12	0.90-1.40	0%	0.675	2	1.15	0.91-1.45	0%	0.587	1
Naringenin	3	1.11	0.89-1.38	0%	0.732	2	1.13	0.90-1.42	0%	0.539	1
Flavan-3-ols	9	0.88	0.80-0.97	16.3%	0.297	7	0.88	0.79-0.97	30.1%	0.198	2	0.91	0.66-1.26	0%	0.335
Cohort	-	-	-	-	-	3	0.91	0.76-1.08	26.9%	0.254	0
Case-control	6	0.87	0.77-0.98	24.7%	0.249	4	0.86	0.76-0.98	46.6%	0.132	2	-	-	-	-
Female	-	-	-	-	-	3	0.94	0.87-1.02	54.7%	0.110	0
Male	-	-	-	-	-	4	1.07	0.99-1.15	23.5%	0.270	0
Anthocyanidines	5	0.75	0.64-0.89	21.9%	0.275	3	0.68	0.56-0.82	0%	0.868	2	1.03	0.73-1.43	0%	0.509
Case-control	4	0.76	0.64-0.90	37.9%	0.185	2	0.68	0.56-0.83	0%	0.668	2	-	-	-	-
Proanthocyanidines	3	0.55	0.35-0.87	74.4%	0.020c	2	0.72	0.61-0.85	0%	0.372	1
Isoflavones	14	0.90	0.80-1.01	54.4%	0.008c	10	0.89	0.77-1.02	65.1%	0.003c	4	0.91	0.78-1.06	5.5%	0.206
Cohort	7	0.98	0.85-1.12	44.0%	0.098	5	1.02	0.90-1.15	43.1%	0.135	2	0.88	0.74-1.05	48.7%	0.163
Case-control	7	0.78	0.70-0.87	37.5%	0.143	5	0.76	0.68-0.85	36.2%	0.180	2	1.02	0.73-1.44	0%	0.430
Female	7	0.95	0.81-1.11	47.7%	0.075c	6	0.93	0.78-1.11	54.3%	0.052c	1
Male	6	0.89	0.82-0.96	35.7%	0.170	5	0.90	0.83-0.99	42.0%	0.141	1

^aSelected study numbers; ^bP values for heterogeneity from Q-test;

^cRandom effects model was used if P < 0.1. RR: Relative risk.