Table 3. Schema of significant dietary parameters on the risks of colorectal cancer (CRC) and adenomas/polyps (AP) per case-control or cohort-control study designs and ethnic subgroups.
| Number of studies (n Case/n Control) |
B12 | Methionine | B9 (Folate) | B6 | B2 | Multivitamin | Fiber | |
|---|---|---|---|---|---|---|---|---|
| CRC | AP | CRC | CRC | CRC | CRC | CRC | CRC | |
| Case/Control | 8 studies (3,337/4,460) ES = 0.07* 4 studies (2,125/2,728) RR, high level = 1.04* |
NS | 10 studies (3,014/4,156) ES: NS 3 studies (2,028/3,013) RR, high level = 0.53**** |
ES = NS 9 studies (3,258/4,407) RR, high level = 0.94** |
3 studies (3,075/4,137) RR, high level = 0.96** |
ES:NS | – | 7 studies (5,564/7,417) ES = −0.09* |
| Subgroups | ||||||||
| R | ES:NS | – | 2 studies (751/979) ES = 0.14** Caucasian |
ES:NS | – | 2 studies (751/979) ES = 0.13** |
– | – |
| CR | ES:NS | – | ES:NS | ES = NS | – | ES:NS | – | – |
| European | – | ES:NS | – | ES:NS RR:NS |
– | – | – | |
| Caucasian | 6 studies (2,998/3,965) ES = 0.07* 3 studies (2,018/2,504) RR, high level = 1.04* |
ES:NS | 3 studies (2,028/3,013) RR, high level = 0.53**** |
ES = NS RR:NS |
– | 2 studies (751/979) ES = 0.13** |
– | 4 studies (3,197/4,200) ES = −0.08*** |
| East Asian | – | – | – | 3 studies (1,150/1,651) ES = −0.12* 3 studies (1,150/1,651) RR, high level = 0.89** |
– | – | – | – |
| Cohort/Control | – | – | NS | ES:NS 3 studies (933/1,564) RR, high level = 0.92* |
ES:NS | – |
7 studies (1,791/3,593) RR, low level = 1.13* |
– |
| Subgroups | ||||||||
| European | – | – | ES:NS | ES:NS RR:NS |
2 studies (178/178) ES = −0.17* |
– | – | – |
| Caucasian | – | – | – | 4 studies (3,790/135,100) ES = −0.86** 3 studies (933/1,564) RR, high level = 0.92* |
– | – | 6 studies (1,503/3,018) RR, high level = 0.81* |
– |
| East Asian | – | – | 2 studies (361/918) ES = 0.15* |
ES:NS RR:NS |
– | – | – | – |
Notes: ES: Effect size; RR: Risk ratio; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001; NS: Not significant; --: No data; Blue font denotes relative risk (RR) related parameters.