What makes hot peppers hot?

Hot Chili peppers originated in Mexico. After the Columbian Exchange, many cultivars of chili pepper spread across the world, used for both food and traditional medicine.

Worldwide in 2014, 32.3 million tonnes of green chili peppers and 3.8 million tonnes of dried chili peppers were produced.China is the world's largest producer of green chillies, providing half of the global total.

But what makes chili peppers hot?

It is an irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related compounds are called capsaicinoids and are produced as secondary metabolites by chili peppers, probably as deterrents against certain mammals and fungi.