Morning energy boost: Is it harmful to drink coffee on an empty stomach?

The acid in coffee causes the pH value in the stomach to decrease, causing the stomach to become more acidic and more stomach acid to be produced. “The stomach can usually handle this situation without any problems,” says nutritionist and diabetes specialist Matthias Riedl (60) from Hamburg (D). The stomach lining secretes a layer of mucus to protect itself from aggressive substances.

But in some people, caffeic acid and stomach acid produced by the stomach irritate the gastric mucosa, says Riedl, unless there is food in the stomach that neutralizes the acid, such as a buffer. This condition especially affects people whose stomach lining is sensitive due to genetic predisposition, smokers whose stomach lining is damaged by harmful substances in cigarette smoke, or elderly people whose stomach lining is less durable.

“Complaints such as stomach pain, heartburn or bloating indicate that you cannot tolerate drinking coffee on an empty stomach,” says the expert. Or that you drink too much coffee in general and need to reduce your consumption.

Protection against cardiovascular diseases

With a few exceptions, drinking coffee on an empty stomach is not harmful. “The positive effects of drinking up to four glasses a day have been scientifically proven,” says Riedl. Black coffee promotes the regeneration of liver cells and supports the elimination of fat from the liver.

According to experts, the caffeine-containing drink is also effective against cardiovascular diseases, reduces inflammation in the intestines and improves intestinal flora. This is because coffee contains polyphenols, called secondary plant substances, which have antioxidant and anti-inflammatory effects. However, if you consume more than four cups a day, the positive effects of coffee will no longer be seen.

changes in the brain

In a 2021 study, researchers at the University of Basel found evidence that regular caffeine consumption reduces gray matter volume in the brain. These are the parts of the central nervous system that are responsible for all human perception processes and motor performance, as well as intelligence.

The changes reappeared after the subjects stopped consuming caffeine for ten days. According to the researchers, the results do not mean that caffeine consumption has long-term negative effects on the brain.