Saw this in the Science Times this morning…
“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.
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.”
Read the rest here.
Of course it’s a little bit different here in Arizona. One of the firs things I discovered when I moved here was that I had to be really intentional about constantly drinking water. The dry air and the heat combine to dehydrate you pretty quickly. Once you learn the signs it’s not too hard to keep on top of, but for the first year I was here I kept wondering why I was always so lightheaded…
I was curious about this once upon a time. Shouldn’t the amount of water someone eneds be variable between people, and for each person? I have days when I drink under a quart and days when I drink over two gallons. Also, “glass” is not a unit of measure and that made me doubt the veracity of the “rule.” I remember finding [somewhere] that the origins of the “rule” may go back [several decades?] to [some doctor]’s work on how much total water intake a person needs. If my memory is correct, he concluded something like four to eight cups per day, which he remarked includes the water content of food. He then disappeared into obscurity.
(I’d be more informative, but these things tend to be like my black dress socks– I know I saw them once, sometimes it would be good to have them again, but I can’t ever remember where they are. And in this case my wife doesn’t know.)