The risk of getting colorectal cancer from eating processed meat is significantly increased in 1 in 3 people who are carriers of a common gene variant, according to a new review published in PLOS Genetics.

Colorectal cancer is the third leading cause of cancer death in both men and women and across most ethnic-racial groups. It is influenced by a variety of factors, including genetic causes and lifestyle factors such as diet.

Previous studies have suggested that eating red or processed meat slightly increases risk of colorectal cancer, and that fruits, vegetables and fiber decrease risk.

Research has focused more recently on how common genetic variants might influence the relationship between certain dietary factors and colorectal cancer risk.

But these studies have mostly looked at the genetic variants called single nucleotide polymorphisms that are directly involved in metabolizing B-vitamins or key nutrients in fruit and vegetables.

The review analyzed 10 studies comprising 9,287 colorectal cancer cases and 9,117 controls. It examines more than 2.7 million common polymorphisms for how they interact with red meat, processed meat, fiber, fruit and vegetables, and how this affects colorectal cancer risk.