Thanks to increased stomach acid and cortisol, there are three main ways drinking coffee on an empty stomach can impact your health. Here’s how:
Heartburn
Coffee may exacerbate acid reflux and cause heartburn, especially if you have a history of these conditions or gastroesophageal reflux disease (GERD), Panzarella says. If you tend to get heartburn after drinking coffee, he says it can help to take an antacid or H2 blocker, such as famotidine (Pepcid AC), on an empty stomach 30 minutes before eating or drinking anything.
Nausea or Diarrhea
The acids in coffee can irritate the digestive system and boost stomach acid production. So can the caffeine, which can also speed up digestion, according to Northwestern Medicine. The effects may be even stronger on an empty stomach without food to buffer the acidity.
This can cause nausea or trigger a bowel movement, Panzarella says. People with irritable bowel syndrome, caffeine sensitivity, heartburn, or gastritis may be more affected, Weine says.
Jitters or Anxiety
As a stimulant, caffeine can activate your central nervous system, increasing your heart rate and blood pressure. This can cause restlessness, jitters, anxiety, heart palpitations, and sleep disruption, Weine says. These symptoms are usually more common if you have a caffeine sensitivity, and drinking coffee on an empty stomach can worsen them, he adds.
