Spicy food can reduce extreme physical pain

Eating a spicy piece of candy might help dull the sensation of intense physical pain, according to a recent small study on human sensory perception. Researchers found that holding a chili-infused gelatin cube in the mouth reduced how violently people reacted to high-intensity laser heat applied to their hands, though it did not relieve the feeling of minor heat pain. The findings were published in the journal Physiology & Behavior.

Capsaicin is the active chemical component that gives chili peppers their famous kick. When consumed, it binds to a specific type of receptor in the body known as TRPV1. These receptors are distributed throughout the mouth, tongue, and skin, and their primary biological job is to detect dangerous environmental heat.

When capsaicin binds to these receptors, it essentially tricks the nervous system. The brain registers a severe burning sensation, even though no physical burning is taking place. This causes an intense bodily reaction without leaving any lasting physical marks or tissue damage behind.

Medical treatments already take advantage of this localized chemical response to treat nerve damage, arthritis, and muscle aches. Topical creams and patches containing high concentrations of capsaicin are routinely used to manage chronic pain. By maintaining a constant, low-level burn, these creams overload the nociceptors, which are the sensory neurons that respond to damaging stimuli.

Over time, this constant stimulation tires the sensory nerves out, blocking them from sending actual pain signals upward to the brain. While the long-term, topical use of capsaicin is a common medical tool, the short-term effects of eating a spicy meal on sudden, acute pain are less fully understood. Previous research has offered mixed results on the topic. Some experiments have suggested that a fiery meal lowers a person’s physical pain threshold, while other trials have pointed toward a rapid pain-relieving effect.

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Yizhou Zhou, a researcher at Chongqing Normal University in China, and a team of colleagues wanted to test whether the immediate sensation of a burning mouth could alter how the brain processes other painful events occurring in the body. They designed an experiment to see if a brief exposure to edible spicy food acts as a temporary painkiller for thermal pain. The research team also sought to figure out if a person’s everyday dietary habits relate to their overall baseline pain tolerance.

To investigate this dynamic, the team recruited 48 healthy young adults from a university campus. Because the sample included fewer than 50 participants, it is considered a small study. To participate, the volunteers had to be free of any chronic pain conditions, psychiatric disorders, or digestive issues like stomach ulcers. The experiment required each volunteer to visit the laboratory on two separate occasions spaced roughly a week apart.

During every visit to the laboratory, participants filled out questionnaires meant to assess their mood and hunger levels. The researchers needed to ensure the volunteers were starting from the entire same emotional baseline on both days, as sudden shifts in mood or appetite can alter how a person perceives physical discomfort.

Next, the researchers calibrated a specialized laser machine for each individual participant. The device emitted precise bursts of infrared heat directly onto the back of the left hand. The team used a heat laser because it activates the exact same nerve pathways as capsaicin, making it an ideal tool to test the overlapping sensory responses.

Participants rated the laser pulses on a standard scale from zero, meaning no sensation at all, to ten, meaning the worst pain imaginable. The technicians adjusted the laser energy up or down until they locked in a specific baseline for each person. They isolated a mild stimulus that rated as a four, along with a harsh stimulus that rated as a seven.

Once the customized baselines were set, the taste test began. During one visit, participants held a gelatin cube laced with crushed chili powder in their mouths for five minutes without chewing or swallowing. Based on chemical analyses, the cube contained a safe, moderate dose of capsaicin designed to induce a noticeable burning sensation. During the other visit, participants held a plain, water-based gelatin cube in their mouths as a control condition.

After the five minutes were up, the participants spit out the gelatin and rinsed their mouths thoroughly with pure water. They immediately received 40 tiny laser pulses to their left hand, divided evenly between the mild setting and the intense setting. After every pulse, the volunteers had five seconds to rate the physical intensity of the pain and how emotionally unpleasant the experience felt.

The mood baseline checks revealed that holding the spicy gelatin in the mouth did not alter a participant’s overall emotional state. The participants were not simply in a better or worse mood during the chili condition. As expected, they did report a robust burning sensation in their mouths that lasted throughout the entire laser portion of the test.

When looking at the low-intensity pain trials, the researchers found no differences between the two tasting sessions. Participants rated the mild heat pulses as equally painful regardless of whether they had just tasted the spicy gelatin or the plain water gelatin. The oral burning sensation offered no relief for minor physical discomfort.

For the intense laser pulses, a different pattern emerged. After holding the chili gelatin in their mouths, participants rated the high-level heat bursts as distinctly less intense than they did after holding the plain gelatin. They also rated the high-intensity pulses as much less unpleasant. The spicy taste stimulation acted as a temporary, intense-pain buffer.

At the end of the second visit, the researchers asked the volunteers to fill out final questionnaires detailing their usual dietary habits. The participants reported how often they ate foods that caused a tingling or burning sensation, and what level of heat they usually preferred on a daily basis. They also completed a standard psychological evaluation designed to measure their general fear of medical and incidental pain.

Individuals who reported a regular preference for spicier foods scored lower on the pain sensitivity surveys. They were less likely to fear imagined painful scenarios and generally expressed a higher tolerance for physical distress. People who ate spicy food more often also preferred a much higher level of heat when they cooked at home.

The authors noted a few possible biological explanations for the results. One leading theory involves conditioned pain modulation, a phenomenon where one localized noxious sensation signals the nervous system to inhibit the perception of a second painful event elsewhere in the body. The intense spicy heat in the mouth might trigger natural descending inhibitory pathways from the brain, muting the harsh feeling of the laser on the hand. Capsaicin is also known to promote the release of endorphins, which act as natural pain-relieving chemicals produced by the body.

Alternatively, the oral burn might simply act as a powerful distraction. If participants were hyper-focused on the burning sensation in their mouths, their brains may have possessed less cognitive bandwidth to process the painful lasers. Future experimental studies will need to incorporate methods to measure attention to fully separate mental distraction from physiological nerve signaling.

The relationship found between dietary habits and pain tolerance also comes with limitations. The survey data only shows a mathematical correlation, meaning it cannot demonstrate that eating fiery foods causes someone to become generally tougher against pain. Some individuals might be born with a higher tolerance for pain, which in turn allows them to enjoy spicier meals. A person’s environment and cultural upbringing likely shape diet and pain tolerance simultaneously.

Additionally, the small sample was entirely composed of young, healthy university students in China. Culturally, dietary habits regarding chili consumption vary widely across the globe. The results of the study might not hold true for older adults, people suffering from chronic pain disorders, or populations who rarely encounter spicy seasonings in their everyday meals. To build on this framework, future trials could test individuals across diverse cultural backgrounds and age spans.

The study, “Acute spicy stimulation reduces laser-induced heat pain perception in healthy adults,” was authored by Yizhou Zhou, Tingran Chen, Yu Peng, Jiayu Zheng, and Zhou Yang.