Red and processed meat ‘increases colorectal cancer risk’

People with a common genetic variant who consume red or processed meat may increase their risk of colorectal cancer. This is according to a study presented at the annual American Society of Human Genetics 2013 meeting.

Furthermore, the US researchers say they also found another specific genetic variant that suggests eating more fruit, vegetables and fiber may lower the risk of colorectal cancer.

To reach their findings, the researchers analyzed 9,287 patients suffering from colorectal cancer alongside a control group of 9,117 healthy individuals.

They also analyzed 2.7 million genetic sequences to determine whether there was a link between consumption of red and processed meat and colorectal cancer.

The study shows that individuals with the genetic variant rs4143094 – a variant that affects 1 in 3 people – demonstrate a significantly increased risk of colorectal cancer linked to the consumption of red and processed meat.

The researchers explain that this genetic variant is located on the same chromosome 10 region that has a transcription factor gene called GATA3 – a gene that has previously been linked to many forms of cancer.

The transcription factor encoded by this gene usually plays a part in the immune system, say the researchers.

Speculating on the link with processed meat, the researchers say that when the body digests it, this may trigger an “immunological or inflammatory” response. But if the GATA3 gene region consists of a genetic variant, it is possible it could encode a dysregulated transcription factor, making it hard to overthrow the response.

However, Jane Figuerido, assistant professor of preventive medicine at the Keck School of Medicine at the University of Southern California, notes that their findings do not mean people without this genetic variant should eat large amounts of red or processed meat.

She adds:

“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.”

Red meat has indeed developed a reputation for increasing health risks. Earlier this year Medical News Today reported on a study showing that consuming red meat may raise the risk of Alzheimer’s disease, while another study linked red meat to increased risk of type 2 diabetes.

But it is not all bad news. The researchers uncovered a positive genetic variant from the study – rs1269486 – on chromosome 8. Results showed that people with this variant who eat more fruit and vegetables may reduce their risk of colorectal cancer.

Findings could lead to better prevention strategies

The researchers note that the findings from this study could lead to better prevention approaches for colorectal cancer based on a person’s genetic variant.

Prof. Figuerido says:

Colorectal cancer is a disease that is strongly influenced by certain types of diets.

We’re showing the biological underpinnings of these correlations, and understand whether genetic variation may make some people more or less susceptible to certain carcinogens in food, which may have future important implications for prevention and population health.”

The researchers emphasize that further research is needed to determine the specific mechanism in which genes regulate the intake of certain foods and the impact for colorectal cancer risk.