Vegetarians who also eat fish have even greater protection against colorectal cancers

 
According to the researchers, the additional benefit from fish probably comes from omega-3 fatty acids. However, they note that even the nonvegetarian group in the study consumed less meat than the average American.

SOURCE
http://www.wsj.com/articles/vegetarian-diet-lowers-risk-for-some-cancers-study-finds-1425913215