US researchers have found that a large glass of water may be the latest blood pressure drug for some patients.
Investigators at Vanderbilt's Autonomic Dysfunction Center reported that water has a powerful blood pressure raising effect in patients who experience fainting spells while standing.
Blood pressure started increasing within two or three minutes after the water was ingested, increased rapidly over the next 15 minutes, and then began to decrease after about 60 minutes. Drinking more water at 60 minutes caused the blood pressure effect to be sustained for another hour.
"There is something about the water itself that causes the increase in blood pressure; intravenous infusion of 475 millilitres of sugar solution did not elicit the effect.
Water might be increasing blood pressure by interacting with osmoreceptors (which sense salt concentrations) or stretch receptors in the stomach or liver," added Jordan, the director of the Clinical Research Center at the Franz University in Germany.