Polar Seltzer is essentially water with bubbles. It contains zero calories, zero sodium, zero sugar, and no artificial sweeteners. The ingredient list is short: carbonated water and natural flavors. For most people, it’s a perfectly healthy drink and a solid swap for sugary sodas or juice.
That said, a few nuances are worth knowing, especially around dental health, digestion, and one contaminant that showed up in testing.
What’s Actually in Polar Seltzer
Polar keeps things minimal. The ingredients are carbonated water and natural flavor essences. There’s no sodium, no caffeine, no gluten, and no animal products. A can delivers exactly what plain water does nutritionally: nothing, in the best possible sense. You’re not adding anything problematic to your diet by drinking it.
This puts Polar in a different category from tonic water (which contains sugar), club soda (which contains added sodium), and diet sodas (which contain artificial sweeteners). If you’re choosing between Polar Seltzer and a can of soda, the seltzer wins by a wide margin every time.
Hydration Compared to Still Water
Seltzer hydrates you just as well as flat water. A randomized trial published in the American Journal of Clinical Nutrition tested 13 commonly consumed drinks on 72 men and developed a beverage hydration index to rank them. Water and seltzer came out equally hydrating. At 100 percent water, the only difference between seltzer and tap water is the dissolved carbon dioxide that creates the fizz, and that doesn’t change how your body absorbs or retains the fluid.
If you struggle to drink enough water throughout the day, seltzer can be a useful way to hit your hydration goals. The carbonation makes it more interesting than plain water for many people, and there’s no penalty for choosing it.
Effects on Teeth
Carbonated water is slightly more acidic than flat water because dissolved CO2 forms a weak acid called carbonic acid. This raises a fair question about enamel erosion. But the American Dental Association points to research showing that plain sparkling water and regular water have roughly the same effect on tooth enamel.
The caveat is citrus-flavored varieties. Citrus flavors tend to have higher acid levels, which does increase the risk of enamel damage over time. If you drink a lot of lemon or lime flavored seltzer daily, you may want to rinse with plain water afterward or alternate with non-citrus flavors. But the risk is still far lower than drinking orange juice, sports drinks, or regular soda, all of which are significantly more acidic.
Digestion and Bloating
The carbonation in seltzer releases carbon dioxide gas in your stomach. If the expanding gas creates enough pressure, it triggers the belching reflex. For most people, this is a minor and brief experience. Research suggests that digestive discomfort from carbonation typically only becomes noticeable when you drink more than about 300 ml (roughly 10 ounces) in one sitting.
People with gastroesophageal reflux disease (GERD) are sometimes told to limit carbonated drinks. The evidence here is actually mixed. Some surveys have found a weak link between carbonated beverages and reflux symptoms, but the overall research is contradictory, and the studies that do show an association often had methodological problems. If you have reflux and notice that seltzer makes your symptoms worse, it’s reasonable to cut back. But carbonation isn’t a universal trigger.
One reassuring finding: nearly all the carbon dioxide you swallow gets absorbed before it reaches the lower digestive tract. So while seltzer might cause some upper-GI bloating or burping, it’s unlikely to cause problems further down.
Bone Health Concerns
You may have heard that carbonated drinks weaken bones. This concern comes from studies on cola, not seltzer, and the two are very different. Cola contains phosphoric acid and caffeine, both of which have been loosely linked to lower bone mineral density in some research. A large study found that cola intake was associated with lower bone density at the hip in women, but non-cola carbonated drinks showed no such association.
A clinical trial published in the British Journal of Nutrition directly tested this. Healthy postmenopausal women drank about one quart of either carbonated or non-carbonated mineral water daily for eight weeks. Blood and urine markers for bone turnover showed no difference between the two groups. Harvard Health has noted that the real issue with soda and bone health likely comes down to displacement: people who drink a lot of cola tend to drink less milk, and the missing calcium matters more than the carbonation itself.
PFAS in Polar Seltzer
Consumer Reports testing detected PFAS (sometimes called “forever chemicals”) in several sparkling water brands, including Polar Natural Seltzer Water at 6.41 parts per trillion. PFAS are synthetic chemicals found widely in the environment that break down very slowly in the body and have been linked to health concerns at higher exposure levels.
For context, 6.41 parts per trillion is a very low level. The EPA’s current advisory for certain PFAS in drinking water is 4 parts per trillion for two specific types, though not all PFAS compounds are treated equally. Polar’s levels were well below those found in some other brands tested (Topo Chico, for example, had significantly higher levels). Whether this amount is meaningful for your health is genuinely uncertain. PFAS contamination is a broader environmental issue, not something unique to Polar or even to sparkling water, as many tap water sources contain comparable or higher levels.
How Polar Compares to Other Options
- Versus regular soda: No contest. A 12-ounce can of soda typically has 35 to 45 grams of sugar. Polar has none. Choosing seltzer over soda eliminates a major source of added sugar from your diet.
- Versus diet soda: Polar avoids artificial sweeteners entirely, which some people prefer. Diet sodas also contain phosphoric acid and other additives that seltzer doesn’t.
- Versus plain water: Nutritionally identical. The only trade-off is a small increase in acidity (especially with citrus flavors) and possible bloating if you drink a lot quickly.
- Versus mineral water: Mineral waters like San Pellegrino or Perrier contain naturally occurring minerals such as calcium and magnesium. Polar doesn’t. If you’re looking for a mineral boost, sparkling mineral water has a slight edge, but the amounts are small.
For the vast majority of people, Polar Seltzer is a healthy, zero-calorie way to stay hydrated. It doesn’t harm your bones, it hydrates as well as still water, and the dental risk is minimal unless you’re drinking citrus flavors all day. The biggest benefit is practical: if the fizz makes you drink more water than you otherwise would, that alone makes it a good choice.