8 glasses of water a day 'an urban myth'
Water and a well-balanced diet 'do far more than water alone,' Australian researcher says
Posted: Jun 10, 2012 12:51 AM ET
Last Updated: Jun 10, 2012 12:48 AM ET
The common advice to drink eight glasses of water a day doesn't hold water, say nutrition and kidney specialists who want to dispel the myth.
"What drove us to drink two litres of water a day?" asks an editorial in this week's issue of the Australian and New Zealand Journal of Public Health.
The recommendation was driven by vested interests rather than health, suggests author Speros Tsindos of the department of dietetics and human nutrition at La Trobe University in Victoria, Australia.Chef Rodney Bowers, left, pours a glass of water as Russell Smith, organizer of a campaign to encourage the drinking of tap water instead of bottled water at restaurants, looks on. Other beverages also help us meet the body's fluid needs, say nutrition specialists. (Aaron Harris/Canadian Press)
"Humans need to maintain fluid balance and need to drink water when required, but should also consider fluid in unprocessed fruits and vegetables and juices. There is further evidence that water and a well-balanced diet does far more than water alone," Tsindos wrote.
"Water is important for health; however, the recommendation of eight glasses of pure water per day appears an overestimation of requirements."
Even a baked potato is 75 per cent water, said nutrition Prof. Susan Barr of the University of British Columbia, who sat on a Canadian-U.S. committee that looked at fluid intake.
"There's nothing magical about water from a glass of water as opposed to water from a food or any other beverage," Barr said.
Drinking caffeinated beverages such as tea and coffee do not lead to dehydration, said Dr. Stanley Goldfarb, a nephrologist at the University of Pennsylvania who reviewed research claims on drinking eight glasses of water and studied how the kidneys handle it.
Let thirst guide you
"Drinking the coffee will count towards your total water intake for the day," Goldfarb said.
Goldfarb said despite the common idea that it's important to "drink eight glasses of eight ounces of water" a day, "There’s no evidence that benefits health in any real way and it really represents an urban myth."
There's no evidence you need to drink more water than what thirst dictates, Goldfarb added.
Studies on desert nomads showed people can consume minimal amounts of water in harsh environments. The military has also looked at how much water soldiers need to take with them when patrolling in hot climates without harming their performance.
"If one is just playing a game of tennis in an indoor facility, for example, or having a short run on a treadmill in an air-conditioned gym, the need to maintain hydration during that is just non-existent," Goldfarb advised.
People have died of dehydration and from drinking too much water too quickly.
A good guide to tell if the body’s finely tuned fluid balance is to check the colour of your urine. If it's very dark, you're on the dry side; if it's very light or translucent, then you need to drink a bit less water, said Dr. David Price, head of family medicine at McMaster University in Hamilton, Ont.With files from CBC's Kelly Crowe
Top News Headlines
- Neil Macdonald: Washington's obsession with leakers
- Julian Assange and Edward Snowden are just the most prominent targets in an all-out legal and propaganda campaign that America's security apparatus is mounting against leakers everywhere, Neil Macdonald writes. more »
- Half of First Nations children live in poverty
- Half of status First Nations children in Canada live in poverty, a troubling figure that jumps to nearly two-thirds in Saskatchewan and Manitoba, says a newly released report. more »
- Who's who in the Senate expense controversy
- Keeping track of the names popping up in the ongoing Senate expenses controversy — from the investigators to the four senators themselves — could be a difficult task for even the most seasoned political observers. more »
- How open is Ottawa's new 'open data' website?
- Treasury Board President Tony Clement is touting the federal government's revamped data portal as a "new natural resource." But that online window for previously published data arrives at the same time the government faces controversy over just how open it really is. more »
Latest Health News Headlines
- Sexually transmitted oral cancers screened with early blood test
- Antibodies to a high-risk type of a virus that causes mouth and throat cancers when transmitted via oral sex can be detected in blood tests many years before onset of the disease, according to a World Health Organization-led team of researchers. more »
- Parents in dark about teens tanning, study suggests
- New research into the use of indoor tanning salons by Alberta teenagers suggests their parents are clueless about it. more »
- Celiacs, diabetics face hard food bank choices
- Life on a limited income is an extra challenge for people living with diabetes or celiac disease, a poverty survey by Women's Network PEI is finding. more »
- Mental illness afflicts most of Calgary's homeless, study finds
- A study has found there is an "overwhelmingly high" rate of undiagnosed and untreated psychiatric illness among Calgary's homeless population. more »
- 2 men jailed in Dominican wedding fight return to Canada
- All-party deal on bills, MP oversight lets House out early
- Are e-cigarettes safe to puff?
- Most groups don't want return of Trudeau speaking fees
- Half of First Nations children live in poverty
- Police probe death of woman, 27, in Kelowna home
- Huge ancient city at Angkor Wat revealed by lasers
- Tim Hortons being circled by Wall Street hedge funds
- Hundreds attend 'Change Brazil' protest in Vancouver