Nicht genug Wasser zu trinken überflutet Ihren Körper mit schädlichen Stresshormonen. Erwachsene, die gewöhnlich weniger flüssig trinken, steigen eine weitaus stärkere Reaktion von Cortisol auf stressige Situationen als diejenigen, die viel trinken – selbst wenn andere Faktoren, wie eine erhöhte Herzfrequenz und das Gefühl der Angst, einheitlich blieben.

I’ve linked to the news release in the post above. In this comment, for those interested, here’s the link to the peer reviewed journal article:

https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00408.2025

From the linked article:

Not drinking enough water floods your body with harmful stress hormones

It’s common advice to drink more water for energy, appetite control and clearer skin – but researchers have now demonstrated that hydration plays an even deeper role in health. It influences how our bodies react, hormonally, to stress, keeping cortisol in check and in turn lowering the risk of many serious health conditions. It’s the first study to show that fluid intake influences cortisol reactivity to stress.

Liverpool John Moores University (LJMU) scientists, investigating whether water influenced stress hormone levels, found that adults who habitually drink less fluid mount a far stronger cortisol response to stressful situations than those who drink plenty – even when other factors, like elevated heart rate and feelings of anxiety, remained fairly uniform.

Using a UK health database, researchers screened 100 healthy men and women aged 18–35 years, selecting 32 who fell into either the lowest or highest 25% of fluid intake. Those in the “low” group drank an average of 1.3 liters per day, while the “high” group had an intake of a average of 4.4 liters daily. Importantly, both cohorts were otherwise well matched for age, sex, sleep quality, anxiety levels and other factors known to affect stress responses.

The researchers found – and this was expected – that the low-intake group consistently showed signs of poorer hydration – darker urine, more concentrated urine and higher copeptin levels. But the striking result came after the stress test.

Both groups reported feeling equally anxious and showed similar heart rate elevation during the mock interview. But their cortisol responses diverged sharply. Across the high-intake group, cortisol levels remained normal among men and women, but for those who didn’t drink a lot of water, their cortisol levels spiked and stayed significantly elevated for 30 minutes after the test.

But do they drink less fluid because they have lower daily sodium intake? It might not be good to simply drink more water.