Today’s Wonder of the Day was inspired by Liam. Liam Wonders, “What are the hottest peppers in the world” Thanks for WONDERing with us, Liam!

You may be surprised to learn that chili peppers are native to the Americas and have been a part of the human diet for thousands of years. Archaeologists in Ecuador have discovered evidence that suggests people have been growing and eating chili peppers for more than 6,000 years.

Christopher Columbus (yes, the same guy we celebrate for "discovering" America) was one of the first Europeans to encounter chili peppers when he began exploring Central and South America. Columbus and other explorers introduced Europeans to the chili pepper when they returned home.

Not long after, Europeans began finding culinary and medicinal uses for chili peppers. In 1494, Diego Alvarez Chance, a doctor on Columbus' second voyage to the West Indies, wrote about the medicinal properties of chili peppers.

As trade between Europe and the Far East increased, the chili pepper was also introduced to the Philippines, India, Korea, and Japan and became a part of their local cuisine, too.

So where does such a little pepper get its big heat? The answer is capsaicin, a chemical in the pepper.

When you eat a pepper, capsaicin comes in contact with pain receptors in your mouth. These pain receptors sense heat. When capsaicin activates the receptors, they send a message to the brain telling it you have eaten something hot.

Your brain responds to the message by raising your heart rate, increasing perspiration, and releasing endorphins, which are special body chemicals that help relieve pain. The highest concentration of capsaicin is present in the white flesh on the inside of a pepper and the coating on the seeds.

Peppers come in all different sizes, shapes, colors, and spiciness levels. In 1912, a chemist named Wilbur Scoville developed a special scale to measure the spiciness of a pepper.

Scoville had trained tasters sample water containing chili pepper extracts, an experiment called the "Scoville Organoleptic Test." By diluting the samples until the tasters could no longer detect any heat or spiciness, Scoville assigned each pepper a number rating called a "Scoville Heat Unit (SHU)."

A habanero pepper, for example, has an SHU rating of 200,000. This means the habanero sample had to be diluted 200,000 times before tasters could no longer detect heat.

The Scoville Scale is still in use today, and peppers range from 0 (bell peppers) to over a million (naja jokolia/ghost chili). Pure capsaicin measures 16 million SHUs!

If you're not a fan of spicy food, chili peppers may not be showing up on your plate anytime soon, but keep an eye out for them at your local hospital. A recent study discovered that capsaicin attacked cancer cells without harming healthy cells nearby. This discovery may be helpful for future cancer research and the development of cancer treatments.

Fun facts about chili peppers:

  • Capsaicin is water insoluble, which means a glass of water won't cool your mouth once you bite into a pepper. If you're looking for relief, try a glass of cold milk instead.
  • Chili peppers are a great source of vitamin C.
  • There are three acceptable forms of spelling chili in the English language: “Chili" (South America and parts of the United States), “Chile" (North America, including parts of the United States), and “Chilli" (Great Britain).

Wonder What's Next?

Hot dog! Join us tomorrow for a bright-yellow Wonder of the Day that goes great with ketchup and is a perennial picnic favorite.