The University of Southern California has identified a common genetic variant, called rs4143094, that affects one in three people. Possessing this gene significantly increases the risk of colorectal cancer from the consumption of red meat and processed meat. The research study was the first to identify the interactions of genes and diet on a genome wide scale, including that there is a genetic variant that lowers colecteral cancer risk when fruits and vegetables are consumed.
Colorectal cancer is caused by multiple factors linked to lifestyle, environmental and genetic causes, and the third leading cause of cancer death in both men and women across most racial groups.
In this study the researchers scoured more than 2.7 million genetic sequences for interactions with consumption of red and processed meat with a population pool of 9,287 patients with colorectal cancer versus a control group of 9,117 individuals without cancer.
The research findings specify that the risk of colorectal cancer associated with processed meat was significantly increased when people possess the genetic variant rs4143094. 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 transcription factor encoded by this gene normally plays a role in the immune system, but carries this genetic variant in about 36 percent of the population.
The assumption is that the digestion of processed meat may promote an immunological or inflammatory response that may trigger tumor development. The GATA3 transcription factor normally would help suppress the immunological or inflammatory response. However, if the GATA3 gene region contains a genetic variant, it may encode a dysregulated transcription factor that impacts its ability to suppress the response.
On chromosome 8, another statistically significant diet-gene interaction was found in variant rs1269486. For people with this variant, eating your fruits and veggies lowers the risk of colorectal cancer.
“Diet is a modifiable risk factor for colorectal cancer. Our study is the first to understand whether some individuals are at higher or lower risk based on their genomic profile. This information can help us better understand the biology and maybe in the future lead to targeted prevention strategies,” said lead author Jane Figueiredo, Ph.D., Assistant Professor of Preventive Medicine at the Keck School of Medicine of USC.
“But we are not saying that if you don’t have the genetic variant that you should eat all the red meat you’d like,” Figueiredo added. “People with the genetic variant allele have an even higher increased risk of colorectal cancer if they consume high levels of processed meat, but the baseline risk associated with meat is already pretty bad.”
University of Southern California (2013, October 24).