Study identifies health benefit of chili peppers
The active ingredient in chili peppers is called dietary capsaicin and researchers at the University of California in San Diego say it could provoke chronic activation of the intestinal lining, reducing the risk for colorectal tumours.
Sensory neurons on the tongue contain a molecular pain receptor known as TRPV1 that distinguishes heat, acidity and spice.
"These are all potentially harmful stimuli to cells," says Eyal Raz, MD, professor of medicine and senior author of the study. "Thus, TRPV1 was quickly described as a molecular 'pain receptor.' This can be considered to be its conventional function, which all takes place in the nervous system."
In their study, which was conducted on mice, Raz and his team found that TRPV1 appears in the intestinal lining.
Here, according to Raz, it gets activated by an element that encourages skin cell reproduction called EGFR.
This is important because the epithelial lining of the intestine gets replaced every four to six days, even faster than the skin on the outside of the body, which replaces itself approximately once per month.
In the study, which was conducted on mice, researchers found that intestinal tumours can appear when the balance of the two is offset.
"A basic level of EGFR activity is required to maintain the normal cell turnover in the gut," says Petrus de Jong, MD, first author of the study. "However, if EGFR signaling is left unrestrained, the risk of sporadic tumour development increases."
Researchers genetically modified mice so that they lacked TRPV1, and as a result, scientists found they were more likely to develop tumours.
Study authors say further research is needed to establish a direct association between colorectal tumours and TRPV1.
"Our data suggest that individuals at high risk of developing recurrent intestinal tumours may benefit from chronic TRPV1 activation," said Raz. "We have provided proof-of-principle."
If this proves to be the case, chili peppers are likely to be in high demand.
Capsaicin is already a practical tool: it is the principal ingredient in pepper spray and it is used as a numbing ointment because of its ability to overwhelm the neurons.
The study was published in the Journal of Clinical Investigation.