Acid reflux occurs when the stomach’s contents shoot back up into the oesophagus, which can cause an unpleasant burning sensation. People with frequent symptoms of acid reflux and heartburn may be diagnosed with gastro-oesophageal reflux disease (GORD). The highest levels of GORD are reported in Europe and the US, with the lowest in Asia.


Although many people report that spicy foods give them acid reflux, the scientific data on this is by no means definitive. The key suspect is thought to be a substance called capsaicin, which gives chillies their heat. Capsaicin activates so-called TRPV1 receptors in the oesophagus to produce a burning sensation.

One small Mexican study found that capsaicin triggered symptoms such as heartburn and chest pain in 28 of 31 people diagnosed with GORD and 6 out of 17 ‘healthy’ people. Meanwhile, a US study found that adding capsaicin to food brought on ‘peak heartburn’ sooner after eating. In 2020, Thai medics reported that GORD patients experienced more severe heartburn after eating a meal containing chilli, although it did not affect healthy people.

Acid reflux and GORD are triggered by a number of factors, especially obesity. Fatty foods also aggravate symptoms because they take longer to pass through the stomach, increasing pressure on the valve that leads to the oesophagus.

A South Korean study found that hot, spicy stews, noodles and fried foods were regular heartburn offenders. The researchers point out that eating too quickly and continuing to eat after feeling full also exacerbates symptoms.

Interestingly, eating chilli regularly could be the best thing to do. A Taiwanese study found that although capsaicin increases heartburn if you eat it once, taking it regularly significantly reduces symptoms. At higher doses, capsaicin acts as a painkiller. Some people indeed report anecdotally that eating chilli or cayenne pepper regularly has cured their GORD symptoms. So maybe that’s the answer.

Extra chillies with everything!

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Asked by: Kate Franklin, Exmouth


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Dr Emma Davies is a science writer and editor with a PhD in food chemistry from the University of Leeds. She writes about all aspects of chemistry, from food and the environment to toxicology and regulatory science.