Eight-glasses-of-water rule may be more myth than miracle cure
Did you drink your eight glasses of water today? You didn’t? Well, don’t sweat it. There’s increasing evidence that we’re getting waterlogged.
It’s been gospel for as long as I can remember that we should be drinking eight glasses of H2O a day and that if we don’t we’re probably going to shrivel up and dry out.
But the medical science people tell me quite sternly that this isn’t so, and even those in the holistic community who hold to the eight-glass rule caution about agua overload.
“There’s a myth and an industry out there that promotes water drinking. People have accepted it despite the medical literature. There is no evidence that drinking large amounts of water is beneficial. Continuously drinking in small amounts probably has no negative consequences, but drinking large amounts at one time can actually be deadly. Water does not flush toxins from the body. If anything, drinking large amounts may impair kidney function. Does it improve skin tone? Your skin is a relatively small part of the body’s cellular complement. Water is distributed throughout the body, not just preferentially to the skin.”
STANLEY GOLDFARB, professor of medicine, University of Pennsylvania School of Medicine, Philadelphia
“We tell patients to calculate about 15 millilitres of water for every pound of body weight. For a person who weighs 100 pounds, that’s about 1½ litres [6 cups] per day. A person working out or in a hot environment would need more. Those with kidney issues should reduce the recommended amount. Water helps keep your energy up and your metabolism going. It helps with clarity. Each individual needs to find the right amount. Chinese medicine advises us not to drink too much water, especially cold, with meals. People drinking warm or hot water require less.”
DU LA, naturopathic doctor, Toronto
“Studying the Walkerton community, we discovered that about 5 per cent of people were drinking more than 3 litres of fluid a day [1 litre is about 4 cups] and thought it was good for them. We picked this up accidentally because they were spilling lots of protein in the urine, which is a marker of kidney damage. We asked them to reduce their volume intake, down to what we perceive to be normal – less than six large glasses of fluid a day – and the majority normalized their protein excretion. We will know more about whether the fluid intake caused kidney damage in the next six months. If you load up with fluid, it will rush to the brain and cause cerebral edema, which, if it’s big enough, can result in death.”
WILLIAM CLARK, nephrologist, professor of medicine, University of Western Ontario, London
“The average amount of fluid that North Americans consume on a daily basis is more than adequate. If someone is dehydrated, their urine will be extremely concentrated. Most people probably do need eight or more glasses of fluid, but that can come in the form of any non-alcoholic beverage or even water in food. You can be well hydrated without drinking any water. You could have milk, juice, tea, a salad, an apple. The benefit of drinking water is that it’s a calorie-free beverage.”
SUSAN BARR, professor of nutrition, University of British Columbia, Vancouver