Dr Jens Jordan, a former postdoctoral fellow in Clinical Pharmacology and lead author of the study, commented on the findings.
He confessed: “We do not know how water raises blood pressure”, but admitted “warm, room temperature, or cold” water still raised blood pressure readings.
Dr Jordan did have a theory, though: “Water might be increasing blood pressure by interacting with osmoreceptors (which sense salt concentrations) or stretch receptors in the stomach or liver.”
Further work is needed to understand why water raises blood pressure in older, healthy individuals.
source: express.co.uk