(NaturalNews) One in three people carries a genetic variant that makes them especially sensitive to increased colorectal cancer risk from processed meat consumption, according to a study conducted by researchers from 27 different institutions and published in the journal PLOS Genetics on April 17.
"Our results identify a novel gene-diet interaction with processed meat for colorectal cancer, highlighting that diet may modify the effect of genetic variants on disease risk, which may have important implications for prevention," the researchers wrote.
Dangers of red and processed meat
Colorectal cancer is the third-most common tumor type and the third-leading cause of cancer death in both men and women of most ethnic backgrounds. It has been linked to both genetic and dietary factors; genome-wide surveys have identified approximately 30 separate gene variants associated with colorectal cancer risk, while consumption of red and processed meat has been linked to increased risk, and consumption of fruits, vegetables and fiber has been linked to decreased risk.
For example, a 2008 study by the National Cancer Institute found that people who ate the most red meat had a 25 percent higher risk of colorectal cancer than people who ate the least. The researchers found that one in 10 colorectal cancer cases could be prevented just by reducing meat intake.
Little research has been conducted, however, into the interaction between these risk factors.
"The possibility that genetic variants may modify an individual's risk for disease based on diet has not been thoroughly investigated but represents an important new insight into disease development," researcher Dr. Li Hsu said.
The researchers compared dietary information, cancer status and roughly 2.7 million genetic variants in more than 18,000 people who had taken part in 10 separate studies later pooled together into the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colorectal Cancer Family Registry. Approximately half the participants had colorectal cancer, and the other half did not.
One in three vulnerable
In all participants, greater red and processed meat intake was associated with increased colorectal cancer risk, while fruit, vegetable and fiber intake was correlated with a lower risk. The researchers further found that individuals with the gene variants rs4143094-TG and rs4143094-TT experience an even greater risk associated with processed meat consumption, compared to those with the rs4143094-GG variant.
This particular gene is notable because it occurs in a place on the genome near a gene known as GATA3, which codes for a transcription factor that plays a role in immune function. Prior studies have linked GATA3 to various types of cancer.
About a third of the population carries the genetic variants found to be associated with greater risk from processed meat consumption
"Our results, if replicated by other studies, may provide us with a greater understanding of the biology into colorectal carcinogenesis," researcher Dr. Ulrike Peters of the Fred Hutchinson Cancer Research Center's Public Health Sciences Division said.
Although the study was not set up to explain the connections between processed meat, the gene in question and colorectal cancer, the researchers speculated that, in people with certain gene variants, processed meat might trigger an immune and inflammatory response that promotes tumor formation.
Researchers hope that further investigation into the connection between dietary and genetic cancer risk could lead to more personalized cancer prevention care.
"Diet is a modifiable risk factor for colorectal cancer," researcher Dr. Jane Figueiredo said. "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."