NEW YORK (Reuters Health) - A new review of three deaths of US military recruits highlights the dangers of drinking too much water. The military has traditionally focused on the dangers associated with heat illness, which has killed a number of healthy, young enrollees, Colonel John W. Gardner of the Office of the Armed Forces Medical Examiner in Rockville, Maryland told Reuters Health. However, pushing the need to drink water too far can also have deadly consequences, he said. "The risk has always been not drinking enough," Gardner said. "And then people who aren't medically attuned get overzealous," inducing recruits to drink amounts of water that endanger their health, he added. "That's why we published this paper: to make it clear to people that overzealousness can be dangerous," Gardner explained. In September 1999, a 19-year-old Air Force recruit collapsed during a 5.8-mile walk, with a body temperature of 108 degrees Fahrenheit. Doctors concluded he had died of both heat stroke and low blood sodium levels as a result of overhydration. During January 2000, a 20-year-old trainee in the Army drank around 12 quarts of water during a 2- to 4-hour period while trying to produce a urine specimen for a drug test. She then experienced fecal incontinence, lost consciousness and became confused, then died from swelling in the brain and lungs as a result of low blood sodium. In March 2001, a 19-year-old Marine died from drinking too much water after a 26-mile march, during which he carried a pack and gear weighing more than 90 pounds. Although he appeared fine during the beginning stages of the 8-hour walk, towards the end he began vomiting and appeared overly tired. He was then sent to the hospital, where he fell into a coma, developed brain swelling and died the next day. It is unclear how much water he drank during the march, but Marines were given a "constant emphasis" on drinking water before and during the activity, Gardner writes in the latest issue of Military Medicine. In an interview with Reuters Health, Gardner explained that drinking too much water is dangerous because the body cannot excrete that much fluid. Excess water then goes to the bowel, which pulls salt into it from the body, diluting the concentration of salt in the tissues. Changing the concentration of salt, in turn, causes a shifting of fluids within the body, which can then induce a swelling in the brain. The swollen organ will then press against the bones of the skull, and become damaged. The researcher added that previous cases of water toxicity have been noted in athletes who consume excessive amounts in order to avoid heat stroke. In addition, certain psychiatric patients may drink too much water in an attempt to wash away their sins, or flush out poisons they believe have entered their bodies. In 1998, the Army released fluid replacement guidelines, which recommend a certain intake of water but limit it to 1 to 1-1/2 quarts per hour and 12 quarts per day. It takes a while for these guidelines to get "permeated out" to everybody, Gardner admitted. In the meantime, he suggested that bases take notice of the mistakes of others, and "not wait for somebody to die from (water toxicity) again," he said. "You can't prevent everything bad from happening," Gardner noted. "But when it does, you have to learn from it." SOURCE : Military Medicine 2002;167:432-434.

