From dessert cocktails to fortified wines and amari, after-dinner drinks are a longstanding tradition in Europe, with popularity slowly but surely growing here in the United States. Of these after-dinner drinks, digestifs featuring bold flavors like bitter and herbal spices — such as Campari, Fernet-Branca, and Amaro Nonino — are increasingly popular choices. Aside from being delicious nightcaps, you may notice that they make you feel a bit lighter — or at least like you can button your pants back up — after a big night of eating.

As the name digestif may suggest, these bitter cordials contain herbal and botanical ingredients that are known to aid digestion. Curious as to why bitter tipples seem to carry curative properties for an unsettled belly, VinePair tapped Denver bartenders Seth VanLaanen of The Family Jones and Stuart Weaver of Lady Jane for more information.

“Bitters were originally created, marketed, and sold as a proprietary medicine to cure certain ailments,” Weaver says. “In the modern day and age, bitters are marketed and sold as digestifs and cocktail modifiers as they do wonders to help balance a cocktail or seamlessly meld flavors together.” Despite their use in a number of cocktails, bitters and digestifs maintain medicinal properties known to calm the stomach.

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“Bitters trigger our salivary glands, activate our palate, and produce more saliva, which in turn triggers our digestive tract and allows the body to process and digest in a more effective manner,” explains VanLaanen. The reason why? Our body’s natural reaction is to treat bitter substances the same way it treats poison. In nature, bitter substances can be observed in a number of toxic plants or can act as a signal that food has or is beginning to spoil. Thus, the human body has evolved to detect these substances and send signals to the brain and body warning that they have the potential to cause harm. Should they be consumed anyway, the human body immediately works to protect the stomach from further damage by releasing hormones in the gastrointestinal tract that stimulate the contraction of the stomach wall, thus promoting digestion of the substance.

So, the next time you have an upset stomach or are feeling overstuffed after a large meal, consider adding a few dashes of bitters to your beverage or sipping on a digestif. “While I can’t speak on bitters’ current medicinal applications,” Weaver says, “I often prescribe bitters and ginger ale to myself and my staff when someone complains of an upset tummy.”