Neither intake of alcohol nor total dietary fiber modified the association between red meat, processed meat, poultry, or fish and risks for colon and rectal cancer (all P-interaction > 0.19). The association betweem processed meat and colon cancer risk tended to differ by cereal fiber intake (P-interaction = 0.06), the risk for colon cancer being elevated only among participants with a low intake ( >0 to ≤ 8 g/d), but not among those with higher intake ( > 8 g/d ). Thus participants with a low cereal fiber intake had a significant, 13% (95% CI: 1.01-1.28) higher risk for colon cancer per each increment of 25 G/d intake of processsed meat. Ahigher intake of fish was associated with a low fruit fiber intake [ >0 to ≤ 2 g/d; adjust IRR per 25 g/d = 0.77 (95% CI: 0.65-1.90)] but not among those with a higher fruit fiber intake (> 2 g/d; P-interaction = 0.01). Detary fiber intake from either source did not affect the risk for recctal cancer associated with red meat, processed meat, poultry of fish intake(all P-interaction > 0.14).