Water Education - Water and Health

What if I can't drink eight glasses of water a day?

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For years we've been admonished to chug eight glasses of water a day--for our skin, for our weight, for general good health. But--surprise--experts say that advice might not hold water. On the one hand, it seems that more people than ever are drinking heavily: College students bring bottles into classrooms; office workers nip from jugs all day long. Many of us are like Gerri Johnson, a 56-year-old kindergarten teacher living in Manhattan Beach, who says, "I carry a bottle of water throughout the day, and I'm always drinking. It flushes out my body, and it's good for my skin."

8 Glasses of Water

At the same time, some nutritionists insist that half the country is walking around dehydrated. We drink too much coffee, tea, and sodas containing caffeine, which prompts the body to lose water, they say; and when we are dehydrated, we don't know enough to drink. Can it be so? Should healthy adults really be stalking the water cooler to protect themselves from creeping dehydration? Not at all, doctors say. "The notion that there is widespread dehydration has no basis in medical fact," says Dr. Robert Alpern, dean of the medical school at the University of Texas Southwestern Medical Center in Dallas.

Doctors from a wide range of specialties agree: By all evidence, we are a well-hydrated nation. Furthermore, they say, the current infatuation with water, as an all-purpose health potion--tonic for the skin, the key to weight loss--is a blend of fashion and fiction and very little science. Consider that first commandment of good health: Drink at least eight 8-ounce glasses of water a day. This unquestioned rule is itself a question mark. Most nutritionists have no idea where it comes from. "I can't even tell you that," says Barbara Rolls, a nutrition researcher at Pennsylvania State University, "and I've written a book on water."

Some say the number was derived from fluid intake measurements taken decades ago among hospital patients on IVs; others say it's less a measure of what people need than a convenient reference point, especially for those who are prone to dehydration, such as many elderly people. Kidney specialists do agree on one thing, however: that the 8-by-8 rule is a gross overestimate of any required minimum. To replace daily losses of water, an average-sized adult with healthy kidneys sitting in a temperate climate needs no more than one liter of fluid, according to Jurgen Schnermann, a kidney physiologist at the National Institutes of Health. One liter is the equivalent of about four 8-ounce glasses.

According to most estimates, that's roughly the amount of water most Americans get in solid food. In short, though doctors don't recommend it, many of us could cover our bare-minimum daily water needs without drinking anything during the day. "Whenever I go to the airport I see all these people carrying around bottles of water, and I wonder, 'What's behind this?' " says Schnermann. "Certainly not science." Try confusion. The way it's almost always stated, in books, magazines, and newspapers, the 8-by-8 rule specifically discounts caffeinated beverages, such as coffee.

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