Brierley Wright, M.S., R.D.

I love sparkling water-so much so that I have a SodaStream at home and at the office. You can imagine, then, how much I looked forward to researching the answer to: is seltzer water good or bad for my health?

Lucky for me, compared to straight-up water, seltzer is just as hydrating, says an American Journal of Clinical Nutrition study. That's good, because about half of us fall behind on the daily recommended 11 to 15 cups of water (from foods and drinks).

Related: 7 Refreshing Foods to Help You Stay Hydrated

The carbon dioxide (CO2) that transforms water into bubbly, refreshing seltzer may make you burp, give you a little gas or aggravate esophageal reflux (GERD), but that's about it. If you've heard seltzer isn't good for your teeth, turns out it depends on what kind you're drinking. The CO2 in ­seltzer makes your mouth more acidic (an acidic environment erodes your teeth's enamel), but only slightly, so plain ­seltzer won't harm your pearly whites. The flavoring added to flavored seltzer, though (often ­citrus-based), can plummet your mouth's pH to a level that is harmful to your teeth. Can't forgo your favorite flavored sip? Pair it with a meal: food is typically more neutral, so it balances seltzer's acidity. Better yet, make your own with a soda maker and fluoridated tap water. The fluoride immediately protects your teeth from acid-inducing erosion and strengthens them over time.

Check the ingredients in flavored seltzers, too: they sometimes deliver no- or low-calorie sweeteners (Equal, Splenda, Truvía), which keeps calories in check, but newer research shows low-cal sweeteners may adversely affect your gut microbiome and even encourage belly fat.

BOTTOM LINE: Seltzer, especially plain, is healthy and hydrating-and beats soda for a fizzy fix.

Foods for a Brighter Smile and Whiter Teeth

May/June 2017