taste for spicy foods likely arose because before refrigeration, spices worked as a food preservative, which is particularly important in hot places where food spoils quickly. Garlic, onion, allspice and oregano are excellent bacteria killers, as are thyme, cinnamon, tarragon and cumin. “People who enjoyed food with antibacterial spices probably were healthier, especially in hot climates,” evolutionary biologist Paul Sherman said. “They lived longer and left more offspring. And they taught their offspring: ‘This is how to cook a mastodon.’”
