The Rumor: Coconut water is more hydrating than H2O

According to some, coconut water is the latest miracle drink. It's gained a reputation recently as the go-to beverage after a workout. In fact, word is that it's better for rehydrating you than standard-issue H2O. But is it all it’s cracked up to be? We spoke to Andrea Giancoli, registered dietitian and spokesperson for the Academy of Nutrition and Dietitics, to take a deeper look at naturally sweet drink.

The Verdict: Coconut water may not be the best choice in every situation

"In the past few years, coconut water has just exploded on the health scene,” says Giancoli. “It definitely has that health halo around it.” But while it's certainly trendy, in most cases, you’re probably just as well off drinking from the tap. “Whenever a new miracle cure comes around, we tend to think if we just eat -- or drink -- enough of that one thing, it will cure all that ails us,” says Giancoli. "However, rather than guzzling a Tahitian island’s worth of the stuff, you’re better off sticking to a balanced diet."

So, what’s making everyone cuckoo for coconut water?

First, let’s take a closer look at what it is: Simply put, coconut water is the clear liquid that sloshes around the inside of young (green) coconuts. If you’re lucky enough to land on a beach in Rio, you can drink it straight from the source. Outside of tropical zip codes, you’ve probably seen it sold in cans or bottles at health food stores.

What’s it made of? Coconut water offers a large dose of certain nutrients. “It’s especially rich in potassium,” says Giancoli, “And potassium is something that a lot of us don’t get enough of since we don’t eat enough fruits or vegetables.”

On average, a can of coconut water will deliver about 500 mg of potassium, roughly what you’d get from a banana or a cup of orange juice, according to Consumerlab.com, which did an in-depth nutritional analysis of the three leading brands of coconut water. And that’s pretty much Giancoli’s point: There are plenty of ways besides coconut water to up your potassium intake. “Bananas are common in our diets,” she says, “but potatoes actually have more. They’re a potassium powerhouse.”

And what about coconut water’s reputation as a super-hydrator?

Like most leading sports drinks, coconut water contains sugar and electrolytes, though it’s lower in both calories and sodium, key facts when it comes to rehydration. “If you’re doing a workout that’s longer than an hour, coconut water may not give you what you need to replace what you’ve lost,” says Giancoli. Same goes for working out in very hot weather.

When you sweat, you lose minerals as well as water, and you need to replace both after a tough workout. However, the main mineral in sweat is sodium, something sports drinks like Gatorade tend to contain far more of than coconut water. And if you're a hard core athlete, that's exactly what you need.

When you crunch the numbers, “An equal amount of Original Gatorade would provide about 150 mg of sodium, compared to a leading brand of coconut water’s 24,” reports ConsumerLab.

And there have also been issues with less-than-truthful product claims: Vita Coco, one of the better-known brands, was forced to change claims on its packaging (such as that it contains "more electrolytes than leading sports drinks") after losing a class action lawsuit in 2012.

As for how coconut water stacks up to trusty old H20, a study found that when comparing coconut water to plain water and a rehydration drink, all three provided adequate rehydration. However, blood sugar levels were restored faster with coconut water, which contains natural sugar, and the rehydration drink than with water.

So, do you need it?

“If you work out for an hour or less,” says Giancoli, “you don’t need a sports replacement beverage. For the casual exerciser, drinking water is enough. If you find that you’re hungry afterward, drink water and eat something.”

Coconut water can also tide you over if you're hungry but don't have food on hand. But be warned: “If you’re exercising more than an hour, coconut water may not be enough [to replace what you've lost],” says Giancoli.

If you drink coconut water before you work out, it will give you a little sugar to get you started, and it is lower in calories than most juices or workout drinks. But be sure to read the label closely: Some bottles contain two servings per container. “If you’re drinking a lot of coconut water thinking, 'Hey, this is good for me,' you could get to the point where you’re drinking too many calories without realizing it,” Giancoli says.

The bottom line: Coconut water is trendy and refreshing, but overall, the star of this drink is its potassium. “Some people really like coconut water and are willing to pay the price, but you should not feel like you have to include it in your diet, or, if you’re not, that you’re missing out,” concludes Giancoli. “It’s expensive, and the nutrients it offers can be found in other foods.”