Is Drinking Seltzer Actually Healthy?

Whether you’re trying to cut back on your soda habit or simply get bored drinking plain water all the time, seltzer water is a popular way to enjoy a carbonated beverage without any added sugar or artificial sweeteners. But is stocking our fridges with seltzer actually healthy for us? Or are these bubbly drinks doing more harm than good? Let’s look at the claims and see what the science has to say about it!

What is seltzer water?

Before we jump into the research, let’s do a quick run-down of the different types of bubbling water.

Carbonated water is the overarching category under which sparkling water, seltzer water, club soda, and tonic all fall. What sets each type of carbonated water apart is the source of the carbonation and the addition of various ingredients.

Sparkling mineral water is the only water of the bunch that is naturally carbonated. Sparkling mineral water comes from naturally bubbling springs and contains various natural minerals. Because the amount and types of minerals vary by water source, different sparkling brands often have their own unique taste.

Seltzer water is the most common of the bunch these days; seltzer water is plain water that’s been carbonated using carbon dioxide (CO2). Unflavored seltzer has a clean taste, with the harshness of the carbonation varying by brand. Flavored seltzers use natural flavorings to achieve the desired flavor, but there shouldn’t be any added sweeteners or artificial sweeteners. However, be on the lookout as some diet soda brands containing artificial sweeteners incorrectly label themselves as seltzer.

Club Soda is water infused with minerals and carbonated by the injection of CO2. The minerals added may vary based on brand, but the most common ones are sodium bicarbonate, sodium citrate, potassium sulfate, and disodium phosphate. While club soda has a more mineral taste than seltzer, they are often used interchangeably, mainly when used as a mixer.

Tonic water is the most unique tasting of all the carbonated waters. It is similar to club soda in that water is infused with minerals and carbonated by adding CO2; however, tonic also has quinine. Quinine is a compound found in the bark of cinchona trees and was traditionally used to prevent malaria. Because quinine has a bitter flavor, many brands add sugar or high fructose corn syrup to balance out the taste. As a result, not all tonic waters are calorie- or sugar-free.

Arguments Against Seltzer and Other Carbonated Beverages

Putting tonic water aside, carbonated beverages are zero-calorie, naturally sugar-free, and made from water. So why wouldn’t they be healthy? Some argue that carbonation in water can damage teeth, weaken bones, and lead to weight gain. There’s also a concern that drinking carbonated water isn’t as hydrating as drinking plain, regular water.

So, are any of these true? Let’s take a look at the research!

Ability to Hydrate

Staying hydrated is essential for good health. When we’re hydrated, our hearts can pump blood more efficiently throughout the body, and our muscles work much better too. And while we all know that drinking water is an essential part of getting adequate hydration, there have been questions about whether carbonated water is just as hydrating.

A recent randomized trial of 72 men looked at the effects of 13 commonly consumed beverages on hydration status. The study found that carbonated water was just as hydrating as still water.

However, I’ve found that carbonated water affects people differently from working with clients. For some, because they enjoy the taste of these waters, they are more likely to drink more fluids throughout the day, resulting in better hydration. On the other hand, the bubbles in carbonated beverages can cause some individuals to feel overly full and drink less throughout the day.

Effects on Tooth Enamel

It’s no surprise that soda is bad for our teeth. Thanks to the high sugar content and acidity, drinking soda regularly can lead to cavities and tooth enamel erosion. While carbonated beverages don’t have sugar, they still have some acidity from the carbonation process, which has some people concerned about negative effects on tooth enamel.

In 2016, the American Dental Association studied the pH of over 387 beverages to determine the erosive potential of each. The study found that carbonated water was much less erosive than other beverages and tended to have the same erosive potential as regular still water.

As a result, the ADA recommends replacing sugary beverages with carbonated water, but they stress that seltzers and other carbonated waters shouldn’t replace intake of fluoridated still-water. 

However, don’t break out the bubbles quite yet. In a study from the University of Birmingham, it was found that some flavored seltzers were just as acidic as orange juice.

Specifically, lemon, lime, and grapefruit were found to be the most erosive as they have citric acid in addition to the carbonic acid already found in seltzer. 

A separate study looking at unflavored still and sparkling water found no significant differences in erosive potential. So, with regard to dental health, plain seltzers and carbonated waters may be the best option. 

Effects on Bone Health

The concern over carbonated water and bone health comes from studies that show lower bone mass density (BMD) associated with carbonated beverages. As a result, some people became concerned that seltzer and other carbonated water would have similar effects.

The Framingham Osteoporosis Study looked at the relationship between carbonated beverage intake and bone density in 1,431 women and 1,125 men. They found that only cola, no other carbonated beverages, was associated with low BMD.

Part of the reason only cola was found to lower bone density may be that cola contains phosphoric acid, which has been shown to interfere with calcium absorption in the bone.

Weight Gain

For many of us, whether or not drinking seltzer can lead to weight gain is an important question as we’ve been told that seltzer is a healthy way to consume fewer calories overall, leading to weight loss.

While the research is still ongoing, a recent study in rats found that carbonated beverages (sweetened and unsweetened) led to significantly greater weight gain than rats given a sweetened but de-gassed carbonated beverage. The researchers then tested this in 20 healthy male humans and found the same results.

These findings are surprising, as it was initially thought the sugar and calories in soda lead to weight gain, not carbonation. But this study showed that even if you keep the sugar in when you take the bubbles out, the weight gain is less.

So why did this happen? The researchers found that carbonated beverages led to significantly greater increases in ghrelin (a hormone responsible for making us feel hungry) than de-gassed beverages. 

However, this was just one study and more research into the long-term relationship between seltzer and weight.

The Bottom Line

So what have we learned? Seltzer and other carbonated beverages can be just as hydrating as regular water, and they haven’t been shown to reduce bone mass density. However, with regards to dental health, try to stick with plain or non-citrus flavors more often to keep erosion of tooth enamel lower.

As far as weight gain goes, the research is still ongoing. While carbonation may increase hunger, so can a lot of other factors. From a dietitian perspective, carbonated waters are a better alternative than sugary sodas and a nice break from regular water. However, it’s still important to hydrate with non-carbonated water as well.