The active ingredient in hot peppers may reduce the risk of colorectal cancer, according to a new study conducted in the laboratory. 
The research team found that capsaicin activated the TRPV1 pain receptor , which reduced tumor growth in the gut. TRPV1 was first detected in sensory neurons, where its role is to protect cells from potential damage due to heat, acidity and spicy chemicals in the environment. 
The new study found that intestinal epithelial cells also expressed it when stimulated by the epidermal growth factor receptor ( EGFR ), which is crucial for intestinal cell growth. 
The researchers found that if EGFR signaling was disrupted, it led to uncontrolled cell growth , which increased the risk of developing a tumor. The research team found that when the TRPV1 pain receptor is activated by EGFR , TRPV1 in turn provides direct negative feedback to EGFR , which reduces the growth of "unwanted" cells in the gut, thus reducing the risk of tumor development
Capsaicin also appears to play a role in activating TRPV1 . Capsaicin is an ingredient in hot peppers that generates heat. It has an irritating property to mammals in general, which is expressed in a burning sensation when in contact with body tissue.
Capsaicin is used in topical medications to relieve pain and is the active ingredient in hot sprays. 
The study data are published in The Journal of Clinical Investigation .