There is a lot of hype about coconut water and health—search the web and you'll find claims that drinking coconut water boosts the immune system, helps with weight loss, prevents aging, or lowers the risk of cancer. The research is just not there to support these claims, and much more research is needed.

Our society is definitely in need of a middle ground though- a beverage option with less sugar, that doesn't have the high level of sweetness we find in artificially-sweetened drinks.

My colleagues and I in the Department of Nutrition at Harvard School of Public Health have called on beverage manufacturers to develop a new class of lower-sugar beverages that have no more than 1 gram of sugar per ounce, with no artificial sweeteners.

We’re talking about drinks that are lightly sweet and don’t have as many calories as sodas and fruit juices. These (1 gram of sugar per ounce) beverages don’t get a “green light” on the How Sweet Is It Scale. We put them in the “yellow” category, meaning that they are a better choice than high-sugar soft drinks, but still have more calories than plain water, so don’t overdo them.

Within our beverage rating system, natural coconut water would just about meet the criteria of our "yellow" category, as it has about 1.3 grams of sugar per ounce. It is a bit lower in sugar and calories than many sports drinks on the market, and much lower in sugar and calories than sugary colas and fruit juices that are heavily marketed to kids. So it could be a better choice for families looking for a beverage that’s a bit less sweet.

It's important to not overdo it -- an 11 ounce container of coconut water has 60 calories, and if someone drinks a few of these during the day, the calories can quickly add up (though not as quickly as if they were drinking soda or fruit juice).

Whatever brand of coconut water you choose, be mindful.  Read the label and watch out for coconut water drinks that are mixed with fruit juices. These are much higher in sugar and calories than natural coconut water – and would fall into our “red” beverage category, meaning that people should drink them sparingly and infrequently, if at all.
You can read more about the Harvard School of Public Health beverage campaign on The Nutrition Source and more about coconut water in this Web MD article  that I was interviewed for .  

Photo by Arvind Balaraman from Freedigitalphotos.net