The Science of Spicy: Four Amazing Things Chili Peppers Can Do

By Maggie Koerth-Baker |

The hottest thing about chili peppers isn't the way they taste; it's everything else they can do for you.

1. They Strangle Cancer

Human cells aren't the happy go-lucky little fellows we'd like to imagine. In fact, our cells commit suicide on a regular basis, via a process called apoptosis. Unlike the messy deaths that happen when a cell is injured or diseased, apoptosis is a peaceful passing, wherein an otherwise healthy cell reaches the end of its life span, then shuts down, shrinks, and is absorbed by its neighbors. But with certain types of cancer, the natural process of apoptosis doesn't occur. Unwilling to go quietly into the great night, cancer cells rage on, refusing to die, continuing to multiply, and eventually forming tumors.

That's where chili peppers come in. New studies have shown that capsaicin—the chemical compound that gives chili peppers their kick—may be the key to controlling cancer cells. During the past few years, research has indicated that capsaicin can induce apoptosis in cancers of the lungs, pancreas, and prostate. In the case of prostate cancer, researchers at Cedars-Sinai Medical Center in Los Angeles found that capsaicin also slows the cancer's ability to grow. This means chili-pepper treatments could be lifesavers for men who've survived one bout of cancer but are at risk of another.

Of course, that doesn't mean that people should start feasting on pepper-only diets just yet. Right now, there's little evidence that gorging on chilies will prevent healthy males from getting the disease. In fact, thus far, all research tests on capsaicin have been limited to Petri dishes and some very unlucky mice. That said, scientists remain optimistic about the pepper's potential to help control the disease.

2. They Fight Off Barnacles

Any good sailor knows that barnacles are bad news. If enough of these water-dwelling pests clamp onto a boat's hull, it becomes less hydrodynamic. In fact, barnacle build-ups can force ships to use as much as 30 percent more fuel. That's why many seafarers choose to safeguard their vessels by coating them with anti-barnacle paint. The only problem is that these paints are generally filled with toxic chemicals and metals.

Fortunately, in the early 1990s, an American sailor named Ken Fischer came up with a better idea. While chowing down on a Tabasco-laced sandwich, Fischer realized that barnacles might not share his love for spicy food. His hunch was right. Before long, Fischer was making millions off his pepper-based repellant, Barnacle Ban.

Surprisingly, barnacles might not be the only sea creatures averse to chili peppers. The Kuna tribe of Panama reportedly still sails with strings of chilies tied to their boats. The peppers supposedly make the ships (and the Kuna themselves) less appetizing to sharks.

3. They Numb the Pain

In addition to killing cancer and fending off barnacles, capsaicin has the ability to dull pain. When it hits the tongue, the spice activates pain receptors that fire up that burning sensation. But after a while, the same process depletes the body of Substance P, a chemical involved in the perception of pain. The message "ouch" stops getting through to your brain, and your discomfort fades.

Medical science has already turned this trick into over-the-counter creams for arthritis, but that's just the tip of the iceberg. Someday, capsaicin could revolutionize anesthesiology. Have you noticed that after a trip to the dentist, you talk funny and can't move parts of your face? That's because traditional anesthesia temporarily deadens your senses to the extent that you lose control of those body parts. In October 2007, however, researchers at Harvard Medical School announced that they'd used capsaicin to numb rats without rendering them immobile. The researchers first injected rats with capsaicin and then with a local anesthetic. As the capsaicin flowed through the pain reception pathways, the anesthetic followed in its footsteps, deadening any discomfort while leaving the rats free to scurry about their cages.

In the future, this could mean better painkillers—ones that could make it possible for women in labor to be mobile after an epidural or allow dental patients to move their faces normally after getting a filling.

4. They Make You Forget How Bad They Taste

Although pepper fanatics are always itching for new ways to assault their taste buds, chilies aren't actually addictive. Numerous scientific studies have shown that chili peppers don't induce physical cravings, withdrawal, or loss of control—the classic signs of addiction. Yet, there is something about peppers that keeps people coming back for more.

Scientists think that when pain receptors come into contact with capsaicin, it triggers the body to release endorphins—chemicals that bind to the same receptors in the brain as opiates such as heroin and morphine. And while endorphin highs from peppers aren't like the ones in Trainspotting, they can provide enough of a euphoric kick to keep people engaged in the actions that release them, such as jogging or bungee jumping. This observation may go a long way toward explaining why humans are the only mammals that keep eating chili peppers, even though the sensation burns. Scientists believe that the little high we get from the spice has helped us convince ourselves that we like the taste. The truth is that we do the same thing—for the same sort of pleasurable payout—with other bitter flavors such as coffee, tobacco, and beer.