What Really Happens to Your Body When You Eat Spicy Food

While some people swear by Sriracha and extra chili flakes, others can't eat anything that's more than mild. Regardless of which type of person you are, the science of spicy foods is fascinating.

Experts explain spicy food's side effects on your heartburn, longevity and more.

It may sound like a silly question, but not all of us are spice connoisseurs. The answer is capsaicin, a chemical compound found in spicy foods, like cayenne pepper, that's responsible for that burning sensation we experience when we eat them.

While you may not love the heat capsaicin gives off, the compound boasts health benefits. For example, capsaicin can serve as an analgesic, or pain reliever, per the National Library of Medicine.

As a topical medication, capsaicin is specifically used to relieve nerve pain. Joint problems like rheumatoid arthritis and skin conditions like psoriasis can also be treated with capsaicin-containing ointments or gels, according to the University of Michigan Health.

Eating spicy foods whole can have other effects on the body. Here are a few of them.

"Several medical conditions can be exacerbated by intake of spicy foods," says Mary Matone, RD, a registered dietitian at the private practice Culina Health.

Take gastroesophageal reflux disease, or GERD, for example. The condition is characterized by the back-flow of stomach acid into the esophagus, which can cause a burning sensation in the upper GI tract and chest.

"While spicy food isn't thought to be a primary cause of GERD, it can definitely exacerbate it," Matone says. "Although the mechanism is unknown, spicy foods may irritate the already afflicted esophagus, causing heartburn and discomfort."

What's more, capsaicin may slow the rate at which foods move through the stomach, increasing the risk of reflux as a result, per a July 2017 study in the ​Journal of Neurogastroenterology and Motility​​.​

Also interesting: It's a common misconception that spicy foods can increase your risk of stomach ulcers, per the University of Chicago Medicine.

"In fact, capsicum may actually reduce the production of stomach acid," Matone says. "As a result, spicy foods, and especially those containing capsicum, may actually help improve symptoms in those with peptic ulcers."

There are a few theories of how spicy foods can contribute to weight loss. Research suggests that spicy ingredients could increase calorie and fat burn or reduce appetite, per an October 2021 review published in the journal ​Appetite​​.​

Various trials included in the review provided people with capsaicinoids, either in supplement or whole-food form. While some of the studies reported modest (about 10 percent) increases in energy burn, the results generally weren't long-lasting.

"While the evidence does suggest that capsicum intake may increase energy expenditure and promote weight loss, it should be noted that this increase is minimal and is not likely to cause significant weight loss without other interventions," Matone says. "[Observed weight changes] may also depend on a person's beginning weight and body fat percentage."

The bottom line: Don't bank on jalapeños being a panacea for shedding pounds. A healthy approach to sustainable weight loss should instead consist of a well-balanced diet and regular exercise for long-term health benefits.

It's not uncommon to get the sniffles as soon as you start eating a spicy dish. Capsaicin is known to loosen mucus, per the University of Michigan Health.

While the reaction can feel annoying, there may be some benefits to those Sriracha-fueled sniffles, including better air circulation and improved drainage from the sinuses.

People who ate spicy foods almost daily were observed to have a 14 percent greater chance of living longer than people who ate foods less than once weekly, per an August 2015 review in ​The​ ​British Medical Journal​​.​

While the study was observational (and therefore can't prove cause and effect), it's possible that capsaicin's anti-inflammatory and antioxidant properties contributed to these potential longevity benefits, according to the Harvard T.H. Chan School of Public Health.

Spicy foods might be good for your heart: Chinese adults who ate spicy foods more frequently and in larger amounts were found to have lower LDL cholesterol levels and LDL-to-HDL ratios compared to adults who ate less or none of the hot stuff, per a July 2017 study in the ​British Journal of Nutrition​​.​

That's encouraging, as lower LDL cholesterol levels are associated with a decreased risk of developing heart disease. But the study reported another fascinating finding: Eating more spicy food was also associated with higher triglyceride levels in the blood, which are a ​risk factor​ for heart disease.

The researchers believe the higher triglycerides could be due to the fact that spicy ingredients are often used to add flavor to plain starches like rice, a staple in the Chinese diet. But excess carbs are converted to fat in the body and can therefore contribute to higher trig levels. In other words, eating more spicy food could also mean eating more refined carbs, which could potentially mean more fat in the blood.

The takeaway: Spicy foods may improve lipid levels, but ​how​ we eat them matters. Emphasize adding chili flakes or hot sauces to nutrient-dense foods like veggies and fish instead of refined carbs.

How the body responds to spicy foods is completely individual.

"While some of the groups mentioned above are generally advised to limit intake of spicy foods, it's important to note that tolerance levels vary from person to person," Matone tells LIVESTRONG.com.

"Additionally, though most of the research supports abstinence from large amounts of spicy foods in these vulnerable groups, there is little research available assessing the impact of smaller doses of spicy foods on these conditions."

If you have a condition like GERD or IBS, talk to a doctor or registered dietitian to learn whether and how much of these foods may work for you. While ghost peppers probably aren't on the menu, a few shakes of pepper may be A-OK.