As with many questions about culinary traditions, the answer is multifaceted. First, chili makes living in the scorching tropics more bearable because this species of capsicum helps cool the body. Yes, that seemingly paradoxical statement is true because the consumption of the essential oils of chili turns the body into, if you will, a walking air-conditioning unit. Chili usually causes the diner to sweat. When the heat of the day or a dry breeze evaporates this perspiration, the diner's skin cools, because as water changes from a liquid to a gas, it absorbs a lot of heat calories from its surrounding environment.
Second, hot chili perks up the appetite, an important consideration because tropical weather does anything but whet the desire for food. On a hot, muggy day in the tropics, you have as much appetite as you would in a steam bath.
Third, hot chili adds needed zest to a diet that would otherwise be, for the most part, comparatively bland. Though tropical fruits are ambrosial delights, vegetables and seafood in the tropics are generally much blander than in the temperate zone.
Fourth, chili is a natural preservative. This makes chili valuable to people who live in the tropics because the hotter the climate, the faster and the more likely food will spoil.
Fifth, as contemptible cooks have long known, chili can swamp the telltale taste of spoilage.
Even chili-climate cuisines can benefit from chili. Besides providing flavor excitement for its own sake, chili aids digestion by accelerating the flow of gastric juices.
** Asian Recipes