Drinking two liters of water per day may not benefit most individuals and even could be harmful, investigators say.
At the Canadian Society of Nephrology annual meeting here, re-searchers from the University of Western Ontario, also in London, presented a study showing a significant correlation between excess urine production—which is usually caused by excess fluid intake—and proteinuria.
The large population-based study un-covered a fivefold higher risk of proteinuria among people with polyuria than among those with normal urine volume, even after taking into account such factors as age, sex, and estimated glomerular filtration rate.
If investigators replicate this finding, further research should be conducted to determine the renal consequences of drinking two liters of water per day, said lead investigator Jessica Sontrop, PhD, assistant professor in the department of epidemiology and biostatistics.
“Such a finding would have important implications, given the silent nature of kidney disease and the widespread, but unsubstantiated, belief that drinking eight glasses of water per day is healthy.”
Drinking too much water called latest threat to health
Canadian doctors are warning drinking too much water may cause loss of kidney function - something they discovered purely by accident.
The study is published in this week's issue of the Canadian Medical Association Journal.
"If you go on the Internet you'll get at least 500 hits on how healthy it is to drink as much water as humanly possible," Clark said. "Some health magazines recommend people drink a minimum of 12 to 15 glasses of fluid per day."
But Clark said flushing the kidneys doesn't help kidney function.
Even doctors believe the medical myth that people should drink at least eight glasses of water a day, according to an article published last month in the British Medical Journal, which traced the notion back to a 1945 recommendation from the U.S. Nutrition Council.
Ignored in the original statement was that most of the fluid people need is found in food, especially fruits and vegetables, the researchers said.
Are You Damaging Your Kidneys Without Knowing It?
Don’t force down 8-10 glasses of water per day unless your thirst dictates it
Your body is not a long plumbing tube that gets cleaner by forcing more water through it. Every time you drink water that your body doesn’t need, your kidneys are forced to spend energy to filter out this excess water. This filtration process puts significant burden on the tiny blood vessels that line your kidneys, which can contribute to the development of chronic kidney disease.
The amount of water that you need depends on a variety of factors. Eating lots of water-rich foods like vegetables and fruits decreases the amount of water you need to drink. Living in a warm climate, regular exercise, sweating, and eating salt all tend to increase your need to drink water. Ultimately, the amount of water you drink should be determined by your sense of thirst on a moment-to-moment basis.
Staying safely hydrated
Generally if you drink enough fluid so that you rarely feel thirsty and produce 1.5 liters (6.3 cups) or more of colorless or light yellow urine a day, your fluid intake is probably adequate. If you're concerned about your fluid intake or have health issues, check with your doctor or a registered dietitian. He or she can help you determine the amount of water that's right for you.
To ward off dehydration and make sure your body has the fluids it needs, make water your beverage of choice. It's also a good idea to: Drink a glass of water or other calorie-free or low-calorie beverage with each meal and between each meal. Drink water before, during and after exercise.
Although uncommon, it is possible to drink too much water. When your kidneys are unable to excrete the excess water, the electrolyte (mineral) content of the blood is diluted, resulting in low sodium levels in the blood, a condition called hyponatremia.
