Asked by: Ella Swanson, Coventry
The heat in chilli is caused by a chemical called capsaicin, which binds to the TRPV1 proteins in the nerves that sense pain and heat. If these receptors are continually stimulated by regular spicy meals then the nerve cells ‘turn down the volume’ by adding phosphate groups to the receptor proteins. This causes the protein to alter its three-dimensional shape and reduces its ability to bind to capsaicin, so you become less sensitive. Our sense of taste also naturally decreases as we get older, so food that used to be intolerably spicy might now produce just a pleasant tingle.