Is bottled water bad for you?

The conversationFor many people, the beginning of the year is a time for making new health resolutions — whether it’s eating more vegetables, cutting back on sugar, or drinking more water.

Adequate hydration is essential for bodily functions such as temperature regulation, transport of nutrients and elimination of waste. Water even acts as a lubricant and shock absorber for joints.

Although most people know they should be drinking more water, it can get a little boring. So how about sparkling water as an option to spice things up a bit? After all, sparkling water is just as good as regular water, right? Not quite.

Aerated liquids

Sparkling water is made by adding carbon dioxide to water. This produces carbonic acid with a slightly acidic pH of between three and four. The “feel” in your mouth you feel after sipping a fizzy drink is actually the chemical activation of pain receptors on your tongue, which respond to that acidity and produce a grumpy taste. And here lies part of the problem, because acid in beverages can damage our teeth.

Glass of mineral water with ice and slice of lime, child and adult blurred in background

Nice to drink but not so good for your teeth. Image source: Bignai/

The outer layer of our teeth, the enamel, is the hardest tissue in the body. It is made up of a mineral called hydroxyapatite, which contains calcium and phosphate. Saliva is mostly water, but it also contains calcium and phosphate.

Normally, there is a balance between tooth minerals and the minerals in saliva. Mouth and saliva normally have a pH of six to seven, but when this falls below five and a half, calcium and phosphate molecules migrate from the teeth into the saliva. This can happen due to the carbonation in carbonated drinks.

Bad for your teeth?

This demineralization creates tiny pores in the tooth mineral and the tooth enamel begins to dissolve. Initially, the pores are microscopic and can still be clogged by re-adding calcium or phosphate, or replacing calcium with fluoride – this is how fluoride in toothpaste protects teeth. However, once the amount of lost tooth minerals reaches a certain level, the pores can no longer be clogged and the tooth tissue is lost forever.

Frequently soaking teeth in acid from carbonated beverages can leach out more minerals than can be reabsorbed, and there is a greater risk of tooth wear or erosion

Although plain sparkling water is better for your teeth than flavored sodas (diet or regular sodas), which have a lower pH, still water is best — it has a pH of around seven. Incidentally, lemonade is not only carbonated, but also contains some “minerals” that provide the taste. This may include sodium. So if you’re watching your salt intake, you need to be careful too.

Pure water

It’s also worth noting that sparkling water is not an appetite suppressant. Despite what you may read online, there is no conclusive scientific evidence that drinking bottled water makes you feel full or curbs your appetite. Yes, drinking carbonated water will fill your stomach (which will likely cause burping as well), but it won’t stay in your stomach any longer than still water.

Even when carbonated water is drunk with food or meals, there is no difference in the rate of gastric emptying compared to still water. Scientifically, it is difficult to measure hunger and satiety, which means that studies examining these are based on or influenced by people’s personal feelings – and of course we humans are all very different. In fact, the European Food Safety Authority, which provides independent scientific advice on food safety, does not endorse health claims made on foods or drinks that claim to increase satiety.

Four supermarket fridge shelves with different brands of bottled water

Bottled water is big business. Image Credit: Toshio Chan/

The NHS recommends drinking between six and eight glasses of fluids a day. In addition to water, this can also include low-fat milk and sugar-free drinks as well as tea and coffee. Water is always a healthy and cheap way to quench thirst. It has no calories, is free and contains no sugars, which can damage teeth – unlike the myriad of sports, energy and fizzy drinks that flood supermarket shelves.

Of course, replacing sugary soft drinks with bottled water is a step in the right direction. It is estimated that soft drinks account for about 25% of sugar intake in adults and increase acidity in the mouth. Most mineral waters do not contain added sugars, but some do. So always read the label.

So if you’re trying to increase your fluid intake, still water is still the preferred option. But if a glass of water isn’t your thing, sparkling water can help you stay hydrated and can be a tasty alternative to plain water – but remember how often you drink it to protect your dental health.The conversation

Nicola InnesProfessor of Pediatric Dentistry, University of Dundee and Suzanne Zaremba, Lecturer in Nutrition, Center for Public Health Nutrition Research, University of Dundee

This article has been republished by The Conversation under a Creative Commons license. Read the original article.

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