Drinking a lot of water is supposed to be healthy, but there is apparently little scientific support for the belief. A review of clinical studies has found no evidence that drinking eight glasses of water a day, the usual recommendation, is beneficial to a healthy person.

Numerous claims have been made about water  that it prevents headaches, removes dangerous “poisons,” improves the function of various organs and is associated with reduced risk for various diseases. But none of these is supported by scientific evidence. The authors were not even able to find a study leading to the “eight glasses a day” rule, whose origin remains unknown.

Image Credit... Tony Cenicola/The New York Times

The researchers, in the June issue of The Journal of the American Society of Nephrology, say some studies have found evidence that drinking extra water helps the kidneys clear sodium, and long-term sodium retention might increase the risk of hypertension, but no clinical significance for the phenomenon has been established. Water also helps clear urea, but urea is not a toxin.