Why peppers are so hot - and why we eat them anyway

"Why do peppers burn your mouth?" asked a young Arlington Heights Memorial Library patron.

Chili peppers produce capsaicin. When eaten it blooms from bite into burn. Those peppers also can ignite churning stomach acids.

But spicy peppers produce many positives. Some people savor the tingly, hot sensations. The pepper not only makes food tasty but also is an ingredient in medicine.

Capsaicin patches and pills can help patients with chronic shingles or arthritis, and bring relief to diabetes patients who lose feeling in their feet. It's possible that peppers in the tropics create microbes that prohibit parasites.

Chilies reflect a global marketplace. The plants originated in Central and South America, and the idea of eating chilies emerged thousands of years ago in Mexico. So it's no surprise people in Mexico eat more chilies than people in other countries - an estimated 17 pounds per person per year.

Mexico outproduces many chili-growing countries with nearly 3 million tons of peppers annually. But China heats up the market with six times more peppers - nearly 18 million tons each year.

Are chili peppers tasty? Hot? Spicy? What happens when you pop a pepper in your mouth?

Taste buds are a hot spice-free-zone - they only sense sweet, sour, umami (savory), bitter and salt. It turns out taste has nothing to do with that burning feeling chilies trigger. Spider webbing across your face is the trigeminal nerve, which picks up the heat sensation in peppers and delivers feelings of pain and temperature along the jawline, cheeks and mucous membranes. Smell contributes by helping to single out flavors.

So what do pepper-eating-people experience when they eat chilies raw, roasted, dried, fresh, as a sauce or salsa or in any other preparation?

The pepper ignites a warning signal that's sent to the brain. Caution! Hot! Tears sprout, noses run, mouths sense fire. Some people love that sensation. Others avoid it. The hotter the pepper, as indicated on the Scoville scale, the hotter the heat sensation.

Birds are perfect pepper pollinators. Scientists have identified a mutualistic relationship between peppers and the starlings in Guam and the Mariana islands. After pecking on pepper plants, starlings poop out chili seeds. The birds' digestive systems help to prepare the seeds for germination.

But nonnative brown tree snakes are devouring the starlings faster than they can disperse pepper seeds, putting peppers and peepers at risk.

"Birds are the gardeners of the forest, and without birds, no one's planting the seeds," said Haldre Rogers, Iowa State University assistant professor in the department of ecology, evolution and organismal biology.

Rogers and study collaborators, Monika Egerer and Evan Fricke, point to the snakes - uninvited ship hitchhikers that invaded the island after World War II - for decimating 10 species of local birds. Expensive remediation to bring back the starlings and invigorate the pepper population will include special snake hunters who will try to reduce the estimated 1 million to 2 million snakes that cover the island.

Check it out

The Arlington Heights Library suggests these titles on peppers:

• "Don't Say A Word, Mamá," by Joe Hayes

• "Green is a Chile Pepper: A Book of Colors," by Roseanne Greenfield Thong

• "How Chile Came to New Mexico," by Anaya A. Rudolfo

• "Little Red Hot," by Eric Kimmel

• "The World In Your Lunch Box," by Claire Eamer