The Wall Street Journal:
As winter settles in and temperatures plunge, people turn to food and drink to provide a little warmth and comfort. In recent years, an unconventional type of warmth has elbowed its way onto more menus: the bite of chili peppers, whether from the red jalapeños of Sriracha sauce, dolloped on tacos or Vietnamese noodles, or from the dried ancho or cayenne peppers that give a bracing kick to Mayan hot chocolate.
But the chili sensation isn’t just warm: It hurts! It is a form of pain and irritation. There’s no obvious biological reason why humans should tolerate it, let alone seek it out and enjoy it. For centuries, humans have eagerly consumed capsaicin—the molecule that generates the heat sensation—even though nature seems to have created it to repel us.
Like our affection for a hint of bitterness in cuisine, our love of spicy heat is the result of conditioning. The chili sensation mimics that of physical heat, which has been a constant element of flavor since the invention of the cooking fire: We have evolved to like hot food. The chili sensation also resembles that of cold, which is unpleasant to the skin but pleasurable in drinks and ice cream, probably because we have developed an association between cooling off and the slaking of thirst. But there’s more to it than that.
Read the whole story: The Wall Street Journal