Overall red meat intake was not associated with risk for ractal cancer. Both intake of beef and pork affected the risk but opposite directions: a higher intake of beef was significantly associated with a lower risk for ractal cancer [adjust IRR per 25 g/d = 0.83 (95% CI: 0.70-0.98)], while a higher intake of pork was significantly associated with a higher risk [adjust IRR per 25 g/d = 1.18 (95% CI: 1.02-1.37)]. No association was found between rectal cancer risk and intake of processed meat or its subtypes, fish, or poultry (Table2)
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).