Some people eat spicy food almost every day. They love the taste and the tingle, but I often wonder: how is all that heat affecting their body.
Eating spicy food can produce a variety of physiological reactions, such as a tingling in the tongue and lips, as well as sweating, said David Julius, who is a physiologist at the University of California, San Francisco in the US.
“We all enjoy sensory experiences; spicy foods make life more interesting,” he said.
But not all of the potential responses are welcome, even for those who enjoy the taste.
Here’s what we know about how spicy food affects the body.
Spicy food lovers are likely to be familiar with one immediate physical reaction — sweating.
That’s because some of the spiciest foods contain compounds that bind to nerve receptors along the gastrointestinal tract, including the mouth, which are activatedby heat.
Chillies, the flavourful backbone of many spicy dishes, contain the compound capsaicin, which binds to those receptors and then sends a pain signal to the brain, as Julius discovered in his Nobel Prize-winning work on the topic.
The main chemicals found in peppercorns, horseradish and mustard also bind to the same receptors, albeit much less potently.
These nerves send similar signals to the brain as they would if you came into contact with actual fire, which is why you might start sweating or become flushed; that’s the body’s way of cooling itself down.
“Capsaicin fools your body into thinking the temperature has risen, and so your brain thinks it needs to shed heat,” Julius said. “In humans, we mostly do that by sweating.”
Eating spicy food in moderation is generally safe for people who don’t already have stomach issues. However, it can cause inflammation to the areas that aid digestion and can sometimes lead to heartburn, stomachaches or diarrhoea.
People with gastritis, which occurs when the lining of the stomach is inflamed, may be especially susceptible to increased abdominal pain.
Studies have shown that consuming spicy foods can be associated with some health benefits. One study found that taking a daily supplement of capsaicin (containing the amount in four or five habanero peppers) sped up metabolism, where participants burned the equivalent of an extra 200 calories per day over a 14-week period. In a 2022 study involving more than 6,000 adults, scientists found that chilli intake was linked with a reduction in calcium buildup in the walls of the coronary arteries, which supply blood to the heart.
It’s unclear, however, whether eating spicy foods can reduce the likelihood of obesity or heart attacks in the long term.
The evidence is mixed on whether spicy foods raise or lower cancer risk. A few studies have found that daily consumption of chillies is associated with an increased risk of esophageal cancer, but not of gastric or colorectal cancers.
And while several experiments performed on cells in labs have found that capsaicin and piperine — the chemical found in peppercorns — may help impede or destroy human breast cancer cells, scientists, don’t yet know if these findings might lead to potential treatment.
One study published in 2015, of nearly half a million people in China, found that those who ate spicy food six to seven times per week for several years had a 14 per cent reduced risk of death compared with those who ate spicy food less than once per week. The researchers thought these results were possibly related to the spicy foods’ antioxidant and anti-inflammatory effects, which can protect againstconditions such as diabetes and certain types of cardiovascular disease.
In rare cases, very hot peppers have caused extreme physiological reactions, such as thunderclap headaches or vomitingso severe it ruptured someone’s esophagus.
If you’ve bitten into food that has more spice than you can handle, reach for something with high fat content, such as milk or sour cream, Julius said. Capsaicin is a fat-soluble compound, so it won’t dissolve in water no matter how much of it you drink.
It’s important to respect how much heat your body can take, Julius added.
But if you love spicy foods and your body can handle them, experts say, there’s no reason to avoid them.