Why Does Spicy Food Burn?

The "heat" from spicy food is not a taste but a pain sensation. Capsaicin, the active compound in chilli peppers, binds to TRPV1 receptors on nerve endings in the mouth and throat. These receptors normally detect temperatures above 43 °C and send pain signals to the brain. Capsaicin activates them at normal body temperature, so the brain interprets the signal as burning heat. This triggers sweating, flushing, and the release of endorphins — the body natural painkillers — which may explain why some people enjoy spicy food. Drinking water does not help because capsaicin is not water-soluble; milk (containing casein) is more effective at washing it away.