Why eating processed meat can be cancerous for certain people

A new study has found that a common genetic variant that affects one in three people, appears to significantly increase the risk of colorectal cancer from the consumption of processed meat.

The study of over 18,000 people from the US, Canada, Australia and Europe represents the first large-scale genome-wide analysis of genetic variants and dietary patterns that may help explain more of the risk factors for colorectal cancer.

Dr Jane Figueiredo at the Keck School of Medicine of the University of Southern California, explained that eating processed meat is associated with an increased risk of colorectal cancer and for about a third of the general population who carry this genetic variant, the risk of eating processed meat is even higher compared to those who do not.

"Our results, if replicated by other studies, may provide us with a greater understanding of the biology into colorectal carcinogenesis," Dr Ulrike Peters of the Fred Hutchinson Cancer Research Center's Public Health Sciences Division said.

The study population totaled 9,287 patients with colorectal cancer and a control group of 9,117 individuals without cancer, all participants in 10 observational studies that were pooled in the largest meta-analysis sponsored by the National Institutes of Health-funded Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colorectal Cancer Family Registry.

Scientists systematically searched 2.7 million variants to identify those that are associated with the consumption of meat, fiber, fruits and vegetables.

A significant interaction between the genetic variant rs4143094 and processed meat consumption was detected.

This variant is located on the same chromosome 10 region that includes GATA3, a transcription factor gene previously linked to several forms of cancer.

The study is published in PLOS Genetics.