Spicy food is very popular, despite the body’s attempts to convey the message that it should be eliminated as quickly as possible, through tears, sweating, and all other bodily functions. What is the reason behind this popularity and why do people enjoy it despite these feelings?
Liam Brown, an associate professor at University College London in the United Kingdom who specializes in the neuroscience of sensory perception and pain, told the British newspaper The Guardian, “Capsaicin – a compound found in peppers – binds to a receptor in the body called TRPV1, which is found in a specialized class of nerve cells called pain receptors, which usually detect things that may harm the body.”
It is like a small fire alarm going off that activates parts of the autonomic nervous system, which regulates various involuntary bodily functions without conscious control.
“That’s what leads to all these physiological effects, like crying, sweating, and runny nose,” Brown adds. “It’s your body’s attempt to get rid of the irritant.”
The TRPV1 gene is also activated by other factors, such as body temperature above 42°C – the point at which heat becomes damaging to tissue – and exposure to piperine, the main active ingredient in black pepper, which gives a much milder response.
Other spicy (but not quite spicy) foods activate different receptors, with TRPA1 dealing with mustard and horseradish, while TRPM8 is mainly responsible for cold temperatures and menthol.
“You can actually find other chemicals that have a much stronger effect on TRPV1 than capsaicin in one plant, Euphorbia resin,” says Brown.
The resinous Euphorbia plant contains resiniferatoxin, a compound similar to capsaicin, often described as about a thousand times stronger, and truly dangerous.
Initial warning
The first evidence of people eating hot peppers dates back to about 7,000 years BC in Mexico and Central America.
Pepper did not enter Europe until around the 16th century, but its popularity has boomed ever since. The global hot sauce market is expected to reach $5 billion by 2030.
“Research is still ongoing into how human brains learn what is safe and unsafe, including foods that are safe to consume,” says Brown. “More recent research emphasizes prediction, context, and controllability. The idea is that when you eat something spicy, you receive an initial ‘heat’ signal that is like an alarm. With repeated exposure, the peripheral response diminishes, and the brain learns that the signal is safe and under control. This shift in predictability and certainty is a big part of why the experience is tolerable, and then rewarding.”
“There’s also the idea of reappraisal, or the fact that through exposure and experience, we reframe the meaning of what pain represents, and that we believe is actually safe for us,” Brown adds. “That sense of control and mastery is important, as well as the social and cultural aspect of doing it with your family or friends.”
As with other initially unpleasant experiences—such as running, a cold shower, or a hot sauna—continuing to endure the initial pain also stimulates the body to release endorphins, providing a kind of light-hearted happiness.