The truth: None of these claims holds water, according to a new study. Below, Stanley Goldfarb, M.D., professor of medicine at the University of Pennsylvania and study coauthor, explains why you can toss the eight-glasses-a-day advice down the drain.
The average woman gets enough fluid through a healthy diet-- about two and a half quarts. Most of that comes from beverages (coffee, tea, and juice as well as water); up to a third is from juicy fare like leafy greens, apples, and yogurt.
If you're breakout-prone, all the water in the world won't keep your pores free of bacteria and dirt. The best approach for clear skin: cleansing, exfoliating, and using products that are oil-free.
Kidneys filter waste from the blood and regulate fluid levels -- two separate functions. The extra H2O you down simply keeps you in the loo.
Bottom line: Rather than relying on wishy-washy water lore, listen to your body -- when you're thirsty, drink up!