Water and its wide range of benefits
Published on August 8, 2008 12:25 AM
A medical study showed that people must drink eight glasses of water a day. But according to other medical-journal articles, there's no scientific evidence for claims that drinking water eight times a day, can bring a wide range of benefits, from speeding weight loss to ridding the body of toxins, fighting constipation, fatigue, dry skin and hastening recovery from colds and flu.
For example, a 10-year study of nearly 48,000 men published in the New England Journal of Medicine in 1999 found that the risk of bladder cancer fell 7% for every cup subjects drank per day.
Other studies have found that the more water people drank the fewer precancerous colon polyps people had. Also researchers have found that women who drank at least five glasses of water a day had a 41% lower risk of fatal heart disease, and men had a 54% lower risk, compared with those who drank just two glasses a day.
Physiologist Heniz Valtin of Dartmouth Medical School discussed these studies and more and he concluded that they didn't support a universal recommendation that everyone drink eight glasses of water.
Jodi Stookey, a scientist at Children's Hospital and Research Center in Oakland, have found that substituting water for sweetened beverages helped female dieters cut overall calories and that women on four popular diets who drank at least one liter of water a day lost more weight than those who didn't.
Urologists do agree that extra water can reduce the recurrence of kidney stones. But they don't know if water will prevent them in the first place. Health Scientists reported that kidney stones occur in 4% to 5% of the population, so it's not practical to tell everyone to drink that much.
Experts also agree that people's water needs vary considerably. For instance, Jacquelin Chan, an epidemiologist at Loma Linda University and the lead investigator on the Adventist heart study, said that some fluids like juice have been shown to increase blood viscosity, whereas water decreases it, at least temporarily. That's why she advice people to drink water frequently during the day. She added that drinking at least five glasses of water a day can reduce blood viscosity.
"If your usual habit is to have a bowl of popcorn or peanuts on your desk, sipping on a glass of water instead is satisfying and keeps your hands and mouth busy," said Karen Miller-Kovach, chief scientific officer at Weight Watchers, which recommends six glasses a day.