Q: How can you get used to eating spicy food? Do your taste buds change, or is there a psychological element at play?
— Alex Klunk, Chesterfield, VA
A: Spicy food tolerance comes from a physical change in how some of the body’s pain receptors react to capsaicin, the molecule responsible for the “hot” in spicy peppers and foods flavored with them. Psychology factors into how much we like the burn, not how we feel the burn.
The spicy heat (as well as temperature heat) is registered through specific receptors on the tongue’s nerve cells. When exposed to capsaicin, these receptors open to allow in sodium and calcium ions, causing the receptors to transmit that hot signal to the brain. However, with repeated short-term exposure to capsaicin, those calcium ions essentially close the receptor door behind them, inhibiting further transmission of pain signals.
Over the long term, with repeated spicy meals, the whole nerve ending starts to degrade in a way scientists are still trying to understand. The nerves aren’t permanently damaged, though, and can grow back. That’s why it takes a regular diet of spicy food to keep the burn at bay.