The first time I ate a chili pepper was an intense experience. Though I knew better, I popped the whole pepper in my mouth on a dare. I was in Mexico on a short-term mission trip, and a local pastor took our group to eat at a restaurant in San Luis Potosi. He held up a little red wrinkled pepper and said, “If you can eat this pepper whole, you are missionary material.” Not one to pass up a challenge, I obliged. What’s the worst thing that could happen?
Without warning, my mouth and throat erupted in flames. Instantly I was sweating, and my nose and eyes watered uncontrollably. The heat relented only after an hour and many glasses of water to quell the inferno. To this day, I have eaten many varieties of chili pepper, but nothing since has equaled that diablo.
Since my first encounter with a hot pepper was in Mexico, it shouldn’t surprise me that even though peppers appear in cuisines around the world, they are native to the Americas. Their journey into the recipes of Europe and Asia began after Christopher Columbus’ voyages connected the Old World with the Americas. Those expeditions sparked the Columbian Exchange of the 1500s, through which peppers spread rapidly along global trade routes. In remarkably little time, cultures around the world adopted these new flavors and wove them into their own culinary traditions.
A burning question about chili peppers is, what makes them so hot? The heat in chili peppers comes from capsaicin (C18H27NO3), a molecule that is found in the placenta of the pepper. You may have seen Poblano, Jalapeño, Serrano, Cayenne, and Habanero peppers in the produce section. Those are all hot peppers, possessing one degree of heat to another. There is a scale for rating the intensity of the heat called the Scoville Scale, named of course, for Wilbur Scoville who came up with it. Scoville Heat Units (SHUs) range from zero to over two million. The rather benign bell pepper sits at the bottom, but Carolina Reapers blow the top off the scale. While peppers are also great sources of vitamins and antioxidants, people eat them for their flavor and heat. Remarkably, the only place in nature that capsaicin can be found is in chili peppers.
| Rank | Pepper | Scoville Range (SHU) | Heat Level |
|---|---|---|---|
| 1 | Poblano | 1,000 – 2,000 | Mild |
| 2 | Jalapeño | 2,500 – 8,000 | Mild to Medium |
| 3 | Serrano | 10,000 – 23,000 | Medium to Hot |
| 4 | Cayenne | 30,000 – 50,000 | Hot |
| 5 | Habanero | 100,000 – 350,000 | Very Hot |
How does capsaicin, whether eaten in peppers or in hot sauces made from them, cause that burning sensation? It comes from nerve receptors (designated TRPV1 by researchers) that activate when tissue encounters dangerously high heat. For example, whether it’s a too-hot sip of coffee or the sharp sting of touching something burning, your TRPV1 receptors fire. They alert your brain to the threat and prompt you to pull away before injury occurs. Capsaicin is fascinating because it binds to those same TRPV1 receptors and triggers the same reaction as actual heat—even though it isn’t physically burning you at all. It only feels like it. So why do some people enjoy chili peppers? Why willingly eat something that feels like fire? It’s partly because your body responds to that perceived pain by releasing endorphins—sometimes rewarding you with a euphoric high.
Chew on this: pain-inducing capsaicin even has medicinal value. According to WebMD, capsaicin may support heart health, weight loss, and pain relief. When mixed into topical creams or patches, it can desensitize pain-signaling receptors. Researchers are also exploring its anti-inflammatory properties and its use in migraine relief—for example, a small trial found that 0.1% capsaicin ointment applied to scalp arteries reduced migraine-related pain. And though it’s still early-stage, animal and cell studies suggest that capsaicin might kill prostate cancer cells or reduce prostate growth from benign prostatic hyperplasia (BPH).
You might wonder if capsaicin elicits a burning sensation animals too? It does, and it discourages them from eating the peppers. Yet birds, lacking TRPV1 receptors, can peck at the peppers, eat the seeds, and sow them by excreting the seeds to spread them far and wide. And while you think about eating hot peppers, think about the misleadingly-named peppermint. Yes, there is a non-poisonous chemical called menthol that triggers receptors that detect cold (designated TRPM8). Found in various mint species, menthol elicits a refreshing sensation very much like eating ice.
It’s such serendipity that peppers and mints both contain harmless chemicals that stimulate our nervous systems with hot and cold. Remember, capsaicin is only found in chili peppers, and menthol only in plants of the mint family. This cool coincidence has not escaped evolutionary biologists’ notice. In fact, there is recognition of how “capsaicin demonstrates the incredible elegance of evolution,” said Joshua Tewksbury in an interview for an article on this very subject. He continued, “Once in a while, the complex, often conflicting demands that natural selection places on complex traits results in a truly elegant solution. This is one of those times.”
Tewsbury is right about elegance. It is elegant that molecules in edible plants trigger sensations that people find enjoyable. It is elegant that the carbon-chained capsaicin yields measurable benefits to human health. The nuance of garden birds, but not other mammals, being able to eat chilis should make someone think.
All of these fun facts stand as yet another testament to the genius of God—the Mastermind who wove profound, interdependent complexity into the fabric of Creation. We are supposed to experience this astounding mound of evidence and conclude that there is a God. Consider the sheer number of edible plants, maybe as many as 30,000 different species—safe, nutritious, and tasty. How did that happen by chance? It didn’t. God providentially loved His Creation to not only feed us, which He could have done with considerably fewer choices, but also bless us with mind-boggling choices to bring us pleasure and joy.
You might be surprised that over 120 medicines are derived from plants, such as aspirin, morphine, and digitalis.
