01 April 2009

There is no scientific evidence establishing the need for the average healthy person to drink increased amounts of water, said doctors from University of Pennsylvania, after an extensive review of literature.

“Drink when you’re thirsty. That’s the way your body is designed.” According to the study entitled “Just Add Water,” increased water intake is only really justified in certain cases, such as for athletes or those engaged in vigorous exercise, those living in hot, dry climates, and people suffering from particular illnesses.

Health Benefits of Water
It is a long held belief that drinking the recommended eight glasses of water per day is essential for everyone. Water has been touted to be helpful not only in removing toxic chemicals from the body and keeping organs in top condition, but for stopping headaches, keeping weight off, and even improving skin tone.

The doctors examined the theory that drinking more water helped the kidneys flush more toxins from the body. They found that while drinking more water does have an impact of the rate at which various substances are cleared by the kidney, there is no indication that this resulted in any actual health benefits. Drinking large amounts of water actually tends to reduce the filtering ability of the kidney. No documentation that an increased amount of water is beneficial to the body’s organs, regardless of whether it is gulped or slowly ingested. They found one small study in which trial participants who drank more water experienced fewer headaches than those who did not, but the statistics were not significant. Dr. Goldfarb cited the case of a woman who, as part of a contest, drank water continuously and very rapidly for several minutes. Shortly afterward, she developed swelling of the brain and died.

Water and Weight Loss
Water is supposedly an ideal aid for those who want to lose weight, creating a sense of fullness, thus curbing the appetite. But, doctors found no clinical trials measuring the effects of water intake on weight maintenance.

Water and Skin Tones
While dehydration can decrease skin tension, no studies were found that showed a clinical benefit to skin tone with increased water intake. In certain cases, drinking a lot of water may actually be harmful.

The Water Intake
An earlier study by Heinz Valtin from Dartmouth also debunked the 8x8 water recommendation (8 ounces, 8 times a day), as well as a few other myths; dark urine does not mean dehydration, thirst doesn’t mean “it’s too late,” water doesn’t help or prevent constipation, cancer or heart disease, and caffeinated beverages count as fluid intake.

Dr. Goldfarb says there is no rational basis for the widespread belief that people need to drink eight glasses of water a day, and isn’t clear where the recommendation comes from. But Valtin speculates that our obsession with water may have evolved from The Food and Nutritional Board of the National Research Council who, in 1945 wrote that “an ordinary standard for diverse persons is 1 milliliter for each calorie of food.” This would amount to about 2-2.5 liters, or 64-80 ounces per day. However, eager readers may have stopped short before reading the sentence noting that “most of this quantity is contained in prepared foods.”

On the other hand, there is also no clear evidence of lack of benefit. There may even be a placebo effect to those eight daily glasses. If you are convinced that a lot of water makes you feel stronger and healthier, so be it. However whoever don’t feel that way should not feel obligated to do so.

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