Is Carbonated Water Good for You? Evidence and Practical Advice

Plain carbonated water is water with carbon dioxide gas dissolved under pressure. This guide covers unsweetened, unflavoured carbonated water. Tonic water, soft drinks and products containing sugar, sweeteners or added acids need separate consideration.

Hydration

Plain carbonated water contributes to fluid intake in the same way as still water. In a 2016 randomised trial of 13 beverages, sparkling water and still water produced similar short-term fluid retention in healthy adult men.

The study measured urine output for four hours after a fixed one-litre serving. It does not establish one drink as better for every person, climate or activity level. Choose still or sparkling water according to preference and tolerance.

Teeth and Acidity

Carbon dioxide forms weak carbonic acid in water. Added acids, especially citric acid, can make a flavoured product more erosive than plain sparkling water.

The American Dental Association says plain sparkling water in moderation may cause only minimal erosion compared with soft drinks and sports drinks. Frequent exposure, added flavouring or citric acid, and holding an acidic drink in the mouth increase the concern.

To reduce acid exposure:

• Choose plain, unsweetened sparkling water.
• Drink it with meals instead of sipping it continuously.
• Do not swish or hold it around the teeth.
• Rinse with plain water after an acidic drink.
• Follow a dentist's advice if you already have enamel erosion or sensitivity.

Bone Health

A Framingham Osteoporosis Study analysis found an association between cola intake and lower hip bone-mineral density in women, but found no significant relationship for non-cola carbonated drinks. This was an observational study, so it does not show that cola caused the difference.

Plain carbonated water does not contain the sugar, caffeine or phosphoric acid found in many colas. Current evidence does not establish carbonation by itself as a cause of lower bone-mineral density.

Bloating, Reflux and Digestion

Carbonated drinks can cause burping, temporary fullness or bloating because they release gas in the digestive tract. The NHS lists fizzy drinks as a possible bloating trigger. People who notice reflux, bloating or pain after carbonated drinks can reduce the amount or switch to still water.

A small 2002 trial compared carbonated water with tap water for 15 days in 21 people with functional dyspepsia and constipation. Symptoms improved in the carbonated-water group, but the study was too small and narrow to support a general treatment claim. Carbonated water should not replace medical assessment for persistent digestive symptoms.

Flavoured Sparkling Water

Check the ingredients rather than relying on the words “sparkling water” on the front of the pack. Look for:

• added sugar or syrup;
• citric acid and other added acids;
• sweeteners; and
• sodium, if a clinician has advised you to limit it.

Fresh citrus also adds acid. Adding fruit at home does not make an acidic drink neutral.

Making Sparkling Water at Home

The main home formats are:

• Countertop carbonator: carbonates water filled into a compatible bottle.
• CO2 siphon: uses individual gas chargers in a pressurised bottle.
• Purifier with carbonation: filters source water and carbonates it in the same appliance.

Compare the appliance price, compatible CO2 supply, cylinder yield, bottle requirements and cleaning instructions. A purifier with carbonation also has replacement filters and may require water, drainage and power connections. The HydroSpark+ is Velta's RO purifier with sparkling, cold, ambient and hot water.

Frequently Asked Questions

Can children drink plain sparkling water?

Plain unsweetened sparkling water does not contain the sugar in a soft drink, but keep still water available too. Ask the child's dentist or clinician about individual dental, digestive or feeding concerns.

Is sparkling water bad for the kidneys?

The carbonation itself has not been established as a cause of kidney disease. Products can differ in sodium, sugar and other ingredients. Anyone with kidney disease or a prescribed fluid or mineral limit should follow their clinician's advice.

How much is too much?

There is no single limit that applies to everyone. Total fluid needs and tolerance vary. Reduce the amount if it causes bloating, reflux or other symptoms, and seek medical advice for persistent symptoms.

Does carbonated water cause weight gain?

Plain carbonated water has no sugar or calories. Flavoured products may contain either. Replacing a sugary drink with plain sparkling water reduces sugar and calories from that drink, but does not by itself guarantee a change in body weight.

Is sparkling water better than still water?

Neither is universally better. Both contribute to hydration. Still fluoridated tap water avoids carbonic and added acids, while some people prefer the taste and texture of sparkling water.