Quarks - the truth about the vagus nerve

The vagus nerve is suddenly everywhere. On social media, people claim that if you are stressed, tense, or feeling low, all you need to do is stimulate your vagus nerve — through ear massages, gargling, singing, breathing exercises, or special electrical devices. It almost sounds too good to be true. But how much of it is actually backed by science?

In this video, we take a closer look at what the vagus nerve really does in the body: how it connects the brain with the heart, lungs, gut, and immune system. Why it plays a central role in the parasympathetic nervous system — the system responsible for "rest and digest." And why heart rate and heart rate variability can reveal whether the body is currently in a state of stress or relaxation.

We also test some of the most popular vagus nerve "hacks": ear massage, the diving reflex, and deep diaphragmatic breathing. Which of these methods truly stimulates the vagus nerve? Which ones simply feel relaxing? And why does the way the nerve is stimulated matter so much?

Because medically, vagus nerve stimulation is indeed a fascinating field. It is already used in the treatment of epilepsy and depression, and is currently being investigated for inflammatory diseases such as rheumatoid arthritis, multiple sclerosis, Crohn's disease, and Long Covid. There is even ongoing discussion about possible links to obesity. However, there is a significant difference between clinically applied vagus nerve stimulation and the simple relaxation hacks often promoted online.

The video is conducted in german.