Eight glasses of water a day myth doesn t float

The only ones still urging consumers to strive to drink eight eight-ounce glasses of water a day are the bottled water companies, argues Dr. Margaret McCartney in a British Medical Journal commentary.

Dr. McCartney reviewed the published literature on this subject and found several studies that did not support the notion that consuming that much water, or any other type of fluid, for that matter, could provide health benefits such as staving off kidney disease or improving one s complexion. She says that most of the studies that support this level of hydration are flawed. There are, however, consequences to over-hydrating, such as hyponatremia, in which blood sodium levels plummet to unsafe levels. Instead of strictly adhering to the eight-glass-a-day rule, says Dr. McCartney, use your own level of thirst to determine how much to drink.

ACSH s Dr. Ruth Kava, who wrote on this subject back in 2001, adds that this faulty recommendation is a misinterpretation of the need for approximately eight glasses of fluid which needn t be consumed in the form of eight glasses of water. For instance, hydration can come from other beverages, as well as from foods with a relatively high water content especially fruits and vegetables.