Salt, water balance and hormones in people and mice
What it found
Long-term high salt intake did not make people drink more water, but made them hold on to water instead.
In mice, extra protein and urea helped the body retain that water.
What they found
Studies in people
Water intake in people
People on long-term high salt intake did not drink more water, which was unexpected. Instead, their bodies retained more water.
Hormones and salt balance
Salt and water balance in people was influenced by changes in glucocorticoid and mineralocorticoid hormones.
Animal and lab studies
Urea and water retention
In mice, eating more protein raised urea levels and the number of urea transporters in the kidney's inner region. This helped the mice retain the water needed to keep their internal balance.
Studies in people and animals
A more complex process
The results suggest that the body's response to high salt is not a simple passive process. It involves hormones, metabolism, food and water intake, and how the kidneys handle salt and water.
What the authors conclude
“Together, the results of these two studies lay the groundwork for future studies to determine how, in the face of chronic changes in salt intake, humans maintain volume and osmotic homeostasis.”
Also in their conclusions
- They say the two studies lay the groundwork for future research.
- They want future studies to work out how people keep their water and salt balance steady when salt intake changes over the long term.
How it was done
For a long time, keeping the body's water and salt balance was thought to be a simple, passive process. These studies tested whether that view is right.
One study followed people on long-term high salt intake and tracked their water intake, water retention and hormone levels. The other studied mice to see how urea and urea transporters in the kidney affect water retention.
What it can’t tell you
- We summarised it from the abstract only.
- The human study followed people over time, so it can show links but not prove cause and effect.
- The mouse findings may not apply in the same way to people.
Who paid
- Conflicts
- Conflict of interest: The author has declared that no conflict of interest exists.
The paper
- Title
- Salt and water: not so simple
- Type
- Study
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Zeidel ML (2017). Salt and water: not so simple. The Journal of clinical investigation. doi:10.1172/JCI94004Free full textPubMed 28414294DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error