Newswise — Capsaicin is the chemical compound found in chili peppers that produces the “heat” we feel when we eat spicy foods. When you eat a hot pepper, capsaicin binds to a class of pain receptors called TRPV1 found in the mouth, on the surface of the tongue and throughout the digestive tract.
“But capsaicin does not actually burn you,” said University Hospitals dietitian Jayna Metalonis, MS, RD, LD. “Instead, it tricks your brain into thinking a temperature change has occurred, resulting in the sensation of heat and pain.”
Not surprisingly, your body’s reaction to capsaicin is to cool itself down – hence the sweating that often accompanies eating very spicy food. Similarly, capillaries dilate so that heat can be directed away from the body through the skin, as seen by the flushed faces and hands of those who drench their tacos in hot sauce.
In its attempt to cool itself down, your body’s temperature will rise, so not all of the heat you experience when eating spicy food is imaginary. Your body will also attempt to rid itself of capsaicin by increasing the production of mucus, tears and saliva, resulting in the runny nose, water eyes and even drooling that still makes that Thai green curry so worth it for many of us.
The mouth-on-fire sensation typically fades after about 20 minutes as capsaicin molecules neutralize and stop binding to pain receptors. As the irritant passes from your mouth into your throat to travel the length of your gastrointestinal tract, it can cause the following reactions:
- A burning sensation in the chest as capsaicin binds with pain receptors in the esophagus.
- Irritation of the phrenic nerve, which controls the motor function of the diaphragm, resulting in hiccups.
- Swelling of the throat, making breathing difficult and/or causing hoarseness of voice.
- Increased production of mucus in the stomach and a temporary increase in metabolic rate, which can cause stomach cramping and pain.
- An increased rate of digestion in the intestines that can lead to diarrhea.
- Nausea and vomiting (usually only if the food is very spicy).
- Painful bowel movements. Capsaicin is never entirely digested, so a portion will pass through the gut and trigger more TRPV1 pain receptors.
The Health Benefits of Spicy Food
While a spicy food challenge isn’t likely to have lasting benefits, there are some health benefits to eating spicy food over time, including:
- Longer lifespan: An extensive population-based study published in BMJ in 2015 found that people who ate spicy food six or seven times a week had a reduced risk in total mortality when compared to people who ate spicy foods less than once a week.
- Lower “bad’ cholesterol: Research has shown that eating red chili peppers can lower levels of LDL (low-density lipoprotein), also known as “bad” cholesterol because of its connection with heart disease.
- Weight loss: Capsaicin may curb appetite and boost metabolism, which can help people burn more calories at rest and during exercise.
- Stomach health: Multiple studies have shown that capsaicin inhibits acid production in the stomach, which may help prevent ulcers.
- Gut health: Perhaps surprisingly, spicy foods can have a calming, anti-inflammatory effect in the gut and improve the microbiome.
- Pain management: Capsaicin is a key ingredient in certain pain relief medications, and it is used in a number of creams and patches to treat conditions such as:
- Back pain
- Joint pain
- Rheumatoid arthritis
- Shingles (post-herpetic neuralgia)
- Tendonitis, including tennis elbow
- Trigeminal neuralgia (a rare facial pain syndrome)
- Cancer prevention: Studies have shown that capsaicin can suppress the growth and metastasis (spread) of several types of cancer cells.
- Skin health: Capsaicin has been shown to reduce inflammation, redness and scaling in skin conditions like atopic dermatitis and psoriasis.
Can Spicy Foods Cause Long-Term Damage?
As the old saying goes, anything in excess can be harmful.
“The good news,” Metalonis said, “is that for most healthy people – even those participating in ‘extreme’ challenges involving consumption of record-setting hot peppers – eating very spicy foods does not pose any serious or lasting dangers to your health and does not usually require medical treatment.”
But she noted there are exceptions. Recently, some high school students in California were hospitalized after having difficulty breathing following participation in the viral social media “one chip challenge,” which involves eating a chip made from some of the hottest peppers on the market. Similarly, stories of people winding up in the ER with “thunderclap headache,” constricted blood vessels in the brain, or spontaneous esophageal rupture after eating the world’s hottest peppers are rare but have occurred.
For people with certain underlying medical conditions, it may be best to avoid spicy foods. These conditions include:
- Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn’s disease
- Celiac disease
- Stomach ulcers (though spicy foods do not actually cause ulcers)
- Gallbladder issues
- Acid Reflux/gastroesophageal reflux disease (GERD)
- Irritable bowel syndrome (INS)
- Anal fissures
If you’re not used to spicy foods, start slow. It’s likely your heat tolerance – and enjoyment – will increase over time, while reaping the many health benefits.
Jayna Metalonis, MS, RD, LD, is a Clinical Outpatient Dietitian with University Hospitals’ Clinical Nutrition Department, which offers comprehensive nutrition services to improve the health and quality of life for patients.