April 2, 2008 -- The health benefits of drinking water, at least for already
healthy people, may have been oversold, according to a new report. The findings
will likely disappoint water-bottle-toting Americans and relieve those who can
never seem to down those eight glasses of water a day, widely recommended for
But there is nothing magical about those eight glasses, at least when it
comes to proven health benefits, according to a new report. "There is no
clear evidence of benefit from drinking increased amounts of water," writes
Stanley Goldfarb, MD, professor of medicine at the University of Pennsylvania,
Philadelphia, and the senior author of an editorial on the topic in the
Journal of the AmericanSociety of Nephrology.
On the other hand, he adds, "There is also no clear evidence of
lack of benefit." There's a general lack of evidence either
Those doctors and others who have been recommending drinking eight glasses
of water aren't basing it on anything scientific, according to Goldfarb. He
concludes that most healthy people don't have to worry about drinking eight
glasses every day.
He emphasizes he is talking about healthy people with kidneys that function
well. And he points out that people who live in hot, dry climates do need to
drink more water to avoid dehydration, as do those who engage in vigorous
Health Benefits of Drinking Water: Search for Evidence
Goldfarb was curious about where the longstanding recommendation about eight
daily glasses of water originated. "In my mind it wasn't that drinking this
extra water would hurt you, but that you might not have to."
So he combed through medical literature dating back to the early 1970s,
trying to find the science to back up the advice.
Turns out, there is no single study and no single outcome that led to the
recommendation becoming popular, he says. Somehow, it took on a life of its
Goldfarb and his University of Pennsylvania colleague, Dan Negoianu, MD,
next examined some popular claims about the health benefits of drinking water,
trying in each case to find scientific evidence.
"We looked at the evidence of some of the so-called urban myths that
have grown up about drinking water," Goldfarb says.