April 11, 2008 - A review conducted by the University of Pennsylvania casts doubt on the perception that drinking large amounts of water is beneficial to your health. The reviewers noted a lack of evidence that drinking lots of water improves skin, curbs appetite, or detoxifies the body. They did say that athletes and those in dry climates may need to drink more than the average person.

The ability of kidneys to process toxins does not seem to increase proportionally to the amount of water consumed. While more water does create more urine, it does not increase the total amount of toxic material removed from the body. There was little or no scientific data to confirm or contradict the claims that extra water could improve skin, reduce headaches, or help people lose weight.

The Institute of Medicine report Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate says that hydration can be maintained over a wide range of total water intake. It concludes that drinking when thirsty coupled with beverages at meals and the water derived from foods are enough to maintain normal hydration levels on a day-to-day basis.

The report goes on to say that individuals who are physically active or exposed to hot environments require more total water intake. There is no evidence of adverse effects associated with habitual high intake of water in healthy people, provided it is approximately proportional to losses.

• Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate

• USDA Dietary Reference Intake Page