The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) has issued a colorectal cancer report allegedly concluding “that red and processed meat increase risk of the disease.” Part of the groups’ Continuous Update Project, which in 2007 covered 749 papers on colorectal cancer, the 2011 report reviews 263 additional papers examining “the links between colorectal cancer risk and diet, physical activity and weight.” According to a May 23, 2011, press release, the findings provide “convincing evidence that both red and processed meat increase colorectal cancer risk,” while “foods containing fiber offer protection.”

Billed by WCRF/AICR as “the most comprehensive and authoritative report on colorectal cancer risk ever published,” the meta-analysis also suggested that “ounce for ounce, consuming processed meat increases risk twice as much as consuming red meat.” WCRF/AICR recommends that “people limit consumption to 18 ounces (cooked weight) of red meat a week – roughly the equivalent of five or six small portions of beef, lamb or pork – and avoid processed meat.”