Chances are you've seen the bright bottles and flashy displays at your supermarket: Vitamin Water … Sobe Life … Oxygen Water … waters with protein and fiber … even waters that offer to cure your hangover or pump up your sexual vitality.
Water may be the oldest drink there is, but enhanced bottled waters are the newest, hottest thing in beverages.
The enhanced water category has become a $1.5 billion industry, with more than 150 products available, says Barry Nathanson, editor of the trade publication Beverage Spectrum. The question: Are there any benefits?
Nutritionist Dr. Pamela Peeke believes that you should think before you drink.
While a little more water can't be bad, some of the purported pluses these enhanced waters tout might not entirely live up to the hype, she says.
For example, what health benefits come from adding more oxygen to water -- as in Active O2? Peeke said you can easily have 10 times more oxygen just by breathing in and out than you'd get by consuming one of these oxygenated waters.
"The bottom line is if you wanted more oxygen, open your mouth and breathe," she said.
Vitamin Water is the country's best-selling enhanced water -- it's even endorsed by such celebrities as Shaquille O'Neal and Carrie Underwood. But along with the water's vitamins, Peeke says it packs another punch too: calories. In fact, an entire 20 oz. bottle of Vitamin Water has 32.5 grams of sugar, just 6½ grams less than the sugars in a 12 oz. can of Coke.
So, are these healthy beverages?
"Define healthy for me," Peeke said. "There's no peer-reviewed research that we're aware of that says in those kinds of combinations and percentages of vitamins and refined sugar, that you're going to suddenly become healthy."
Coca-Cola, the maker of Vitamin Water, told ABC News in a statement that "we don't make health claims beyond nutrient content claims for our products. We state very clearly on our label what's in our product and consumers can be sure they are receiving the nutrients listed in each bottle of Vitamin Water."
'Boost Memory, Mental Sharpness' With Water?
Other enhanced waters also add ingredients that sound like they're good for you, such as protein and fiber, to help curb your appetite. Kellogg's created a drink called K20 Protein Water that has 5 grams of protein, 5 grams of fiber and 50 calories.
The company's ad says the product "helps you take the edge off your hunger and still lose weight."
But Peeke said, "Five grams of protein probably is not going to do that. You're going to feel fuller just having drunk the entire bottle of water. Drinking this will not stop you from eating that large slice of cake in front of you."
Kellogg's said, "There are numerous published studies and articles on how protein and fiber work to promote satiety, and we relied on this data to support our K20 claims."
What about a water that says on its cap that it was "created by physicians"? That is a big selling point for the waters from Function, founded by 32-year-old orthopedic surgeon Dr. Alex Hughes.
"We spend so much time and effort either developing devices or pharmaceuticals to help sick people," Hughes said, "but very little time necessarily spent trying to enhance the lives of healthy, hard-charging adults."
Hughes said he and his friends decided to develop drinks for weekend warriors like themselves. Along with a drink designed to abate hangovers and another drink touted to boost sexual vitality, Function offers a beverage called Brainiac, which claims to "boost your memory and mental sharpness," thanks to ingredients like soy PS, zinc and ginkgo biloba.
Peeke is wary.
"You're just going to assume, 'wow, that sounds sort of medical and I got to trust him," she said. "He's got an M.D., for crying out loud. Be careful here. ... Look for the research that goes with it."
Function cites a host of supportive studies to bolster its claims, but the studies are of the ingredients and not the drinks.
"We test that that ingredient is still in its functional form on the other side," Hughes said, "and then that's our criteria for how we know that that functional ingredients is still in effect in the product."
Brainiac Water vs. Hawaiian Punch
No one has ever officially tested Brainiac, so "20/20" decided to.
Dr. Thomas Crook has run hundreds of studies on memory during the last 37 years. He and his colleagues at the Cognitive Research Corporation in St. Petersburg, Fla., agreed to construct a small test for "20/20" with 12 people to see whether drinking one bottle of Brainiac really would improve memory.
A group of people were given a few computerized tests, like recalling names with faces, to establish their basic memory levels. Then, in unmarked glasses, some were given Function's Brainiac and others were given a placebo. After drinking the beverages, each took the memory tests again.
The results of the unofficial test? Not only was there no sign that Brainiac boosts memory, the group that drank the placebo -- a Hawaiian Punch mixture -- did slightly better than those who drank Brainiac.
In a response, Function says that because Crook's experiment "comprised only 12 test subjects" it had generated "no statistically significant findings."
Crook agrees, but said from his experience the results "didn't surprise me ... because I read the papers that were sent and I looked at the amount that they were adding -- the amount of PS, the amount of ginkgo they're adding to the product. They're so small that no one has ever shown any effect."
Seems like when it comes to enhanced water, it is up to the consumers to make healthy choices -- and to read the labels carefully.
Besides, Peeke believes, there's another choice you might want to consider, too. "You know something? At the end of the day, it's all about having just plain old water. "