Reality: Not so. In principle, the 90 to 125 (or so) ounces recommended by the Institute of Medicine would include your morning coffee, the soda you drink with lunch and even a glass of wine at dinner. Practically speaking, however, caffeinated, sweetened and alcoholic drinks pack chemical cargoes (or trigger chemical reactions) that demand significant amounts of fluid to properly process and filter. As a result, nonwater beverages can actually set you back, water-wise, many experts suggest. “They can actually dehydrate the body,” says Haas.
For example, says Vasey, drinks like coffee, black tea and cocoa are very high in purines, toxins that must be diluted in large quantities of water to be flushed from the body.
Artificially sweetened drinks add to the body’s toxic burden. Sugar and coffee also create an acidic environment in the body, impeding enzyme function and taxing the kidneys, which must rid the body of excess acid.
Moreover, says Vasey, caffeine found in coffee, black tea and soft drinks adversely affects your body’s water stores because it is a diuretic that elevates blood pressure, increasing the rate of both the production and elimination of urine. “The water in these drinks travels through the body too quickly,” says Vasey. “Hardly has the water entered the bloodstream than the kidneys remove a portion of the liquid and eliminate it, before the water has time to make its way into the intracellular environment.” (For more on the importance of intracellular hydration, see “Myth No. 5.”)
Bottom Line: Moderate consumption of beverages like coffee and tea is fine, but be aware that while some of the fluids in nonwater beverages may be helping you, certain ingredients may be siphoning away your body’s water stores. So, when you’re drinking to hydrate, stick primarily with water. And, if you’re looking for a pick-me-up, try sparkling water with a squeeze of citrus.