Chili peppers are a staple part of the cuisine in Central America, Asia, and India, while in the US you can find countless varieties of hot sauce, often with the words “inferno,” “insanity,” or “fire” on the labels.
It’s this heat, of course, that draws so many to add chili peppers to their meals, and it’s also the reason for their many medicinal properties, including pain relief.
Chili peppers’ heat comes from capsaicin, a compound produced to protect the peppers from fungal attack. Capsaicin is colorless and odorless, but when you eat it, capsaicin tricks your brain into perceiving heat where it touches your body.
Birds, interestingly, are not affected by capsaicin, and this allows them to widely disperse chili seeds for the plants’ survival. Virtually every other mammal, however, is – although humans are believed to be the only animal that chooses to willingly eat them.
How Chili Peppers Trick Your Brain
Your nervous system contains heat-receptor proteins known as TRPV1 receptors. Located in cells in your skin and digestive system, these receptors remain inactive unless you’re exposed to temperatures above 107.6 degrees F (42 degrees C).
At this point, you'll experience heat and pain, warning you to stay away from the source of heat. When you eat a chili pepper, capsaicin binds to and activates TRPV1, so even though you’re not actually in danger, your body thinks it’s being exposed to extreme heat.
As explained by the New York Times:
“…in mammals it [capsaicin] stimulates the very same pain receptors that respond to actual heat. Chili pungency is not technically a taste; it is the sensation of burning, mediated by the same mechanism that would let you know that someone had set your tongue on fire.”
The intensity of heat in peppers is measured by the Scoville scale, which was developed by pharmacist Wilbur Lincoln Scoville in 1912. While a bell (sweet) pepper has a score of zero, pure capsaicin can surpass 15 million Scoville Heat Units (SHU).
For comparison, jalapeno peppers range from 2,500 to 8,000 SHU, while Scotch Bonnet peppers can be upwards of 350,000. Ghost chilies, which are even hotter, have a potency of about 900,000 SHU. I am growing three ghost pepper plants and can confirm they are indeed very hot.
