The “gut punch” isn’t just metaphorical: Unpleasant sensations prompted by fear or disgust are linked to a more acidic pH in the stomach.
You know that “closed stomach” feeling that catches us after a bad scare or in front of a disgusting scene? It has precise biological basis: according to an Italian study still in pre-publication, fear and disgust are connected to one increased acidity of gastric juicesthe secretions present in the stomach. In short, the perceived intensity of these emotions would be directly connected to the pH of the digestive fluids.
Real-time analytics. A group of neuroscientists from the “La Sapienza” University of Rome led by Giuseppina Porciello asked 31 healthy male volunteers with an average age of 24 to ingest a pill sensor capable of measuring pH, pressure and temperature in the tract digestive tract before being normally excreted in the faeces.
As the capsule recorded from inside the stomach, the boys watched a series of short films designed to trigger disgust, fear, happiness, sadness, or a neutral emotional state.
A two-way street. After each video, participants completed a questionnaire on the intensity of perceived emotions. Films that prompted disgust or fear were linked to a lower, or more acidic, pH in the stomach than normal.
The volunteers who reported the most intense emotions of fear or disgust also had the most acidic gastric juices, but it is not clear which of the two factors influences the other: that is, whether it is the negative emotions that “sour” the digestive environment or if, on the contrary, a higher acidity of the stomach influences the intensity of the perceived emotions.
Consumed by anxiety. Past research has linked negative emotions such as stress caused by job loss to an increased risk of stomach ulcers, injuries caused by excess acidity.
To better clarify the relationship between what we feel and the physiological response of the digestive system, however, other studies should be planned: for example, subjects could be administered protein pump inhibitors (gastroprotective drugs that prevent the stomach lining from producing an excess of acid ) to understand if this alters the intensity of negative emotions.
A report to be investigated further. The results will have to be confirmed on a larger and more varied sample of volunteers, but once again research highlights the relationship between the brain and the digestive system in emotional responses.
A field of analysis which, in addition to being interesting in itself, could serve to improve people’s well-being: for example, by alleviating chronic digestive disorders, important psychological benefits could be obtained.