The beverage industry is touting a natural resource with potent healing powers, one that promises to boost the immune system, aid weight loss, ease sore muscles and even fight hangovers.

It's called water.

But this isn't bland old tap water. It's flavored and “nutritionally enhanced” bottled water that has been jazzed up with everything from cucumber to mango and grapefruit extracts, infused with vitamins, minerals and electrolytes and loaded with herbal supplements, antioxidants and oxygen.
 
Known as “functional beverages,” thirst quenchers such as VitaminWater are especially popular with consumers ages 18 to 34 looking for a boost. The waters don't just hydrate; they claim to “protect your skin from the inside out,” “revive your soul,” “improve your mood” and “increase energy and alertness.”
 
Whether fortified water can deliver on all those promises is still up for debate. Critics say there's no science to show enhanced water has more health benefits than less-expensive tap water, while environmental organizations, religious groups and even restaurateurs argue that all bottled water — enhanced or not — is a wasteful and insupportable use of fossil fuels because of the costs associated with its manufacture and transportation.
 
From a nutritional standpoint, experts maintain that it's better to get nutrients through whole foods. They also point out that taking extra vitamins doesn't necessarily make you healthier.
 
But Americans are drinking up fortified waters anyway. From 2004 through 2006, sales for enhanced waters and sports drinks grew by 73 percent, to $1.2 billion, according to the market-research firm Mintel International Group.
 
But is it necessary? Although the bottled-water association recommends drinking eight glasses a day of 8 ounces each, the Institute of Medicine says “the vast majority of healthy people adequately meet their daily hydration by letting their thirst be their guide.”

“Most people need to drink two quarts of water a day,” said Marion Nestle, a professor in the Department of Nutrition, Food Studies and Public Health at New York University. . “But these quarts do not have to come from water itself; they can also come from anything with water in it.”

Although artificially vitamin-enriched food and drinks may sound beneficial, they're not the same as foods with naturally occurring vitamins and nutrients, wrote Renee Loux in “The Balanced Plate” (Rodale, $22.95). In many cases, the body can't do much with the added nutrient because it can't absorb it.

Endurance athletes who have lost electrolytes through sweat may benefit from electrolyte-enhanced drinks, for example, but for most people, the drinks simply offer extra calories.

“There's not a single drink out there — from Enviga to SmartWater — that has any proof of impact,” said nutrition professor Barry Popkin, who directs the Interdisciplinary Center for Obesity at the University of North Carolina at Chapel Hill.

Still, it's a smart idea to hydrate. And if enhanced waters help people consume less calorie-laden soda, there's a place for them in a diet, said registered dietitian Roberta Duyff, author of The American Dietetic Association's “Complete Food and Nutrition Guide” (Wiley, $24.95).

Chicago Tribune