Cordial, squash, fruit drinks and most flavoured waters affect children's teeth in two ways at once: the sugar feeds the bacteria that cause decay, and the food acids soften enamel directly, so even the sugar-free versions are not tooth-safe when a child sips them through the day. A glass of cordial looks harmless next to a can of soft drink, yet Better Health Channel puts a 250 mL glass of blackcurrant cordial, made up to the label directions, at about 22.75 g of sugar, close to six level teaspoons. Water and plain milk are the drinks every Australian guideline recommends for children.
Written by Dr James Tran, BDent (University of Sydney), MICOI, GradDip (Oral Implants), general dentist at Lumi Dental in Melrose Park.
The short version
- Cordial is mostly sugar and citric acid. Made up as directed, a 250 mL glass carries close to six teaspoons of sugar.
- Fruit drinks and squash are not juice. Better Health Channel's example is 25% juice with about 26 g of sugar per 250 mL.
- Flavoured and sparkling flavoured waters are usually sugar-free but acidic enough to erode enamel; our guide to sparkling water and enamel covers the plain versions.
- How often a child sips matters more than what is in the bottle. Enamel stays softened for around 20 to 30 minutes after each mouthful.
- Water and plain milk are the only everyday drinks children need. Anything sweet belongs with a meal, in a small cup, not every day.
Sugar plus acid: why a sweet drink is a double hit
Two separate things happen when a child drinks cordial. The first is decay: bacteria in plaque turn sugar into acid, and every mouthful restarts the process. The second is erosion, which healthdirect describes as two steps: acid in the drink softens the enamel surface, and the softened layer is then worn away by chewing and brushing. Children are more exposed than adults, because baby tooth enamel is softer and more easily damaged by acid. In my experience a child who carries a bottle of cordial shows both: early decay between the back teeth, and glassy, cupped edges on the front teeth where acid has thinned the enamel.
Cordial, squash and fruit drinks: what is in the glass
Cordial
Cordial is a sugar and food acid concentrate, usually with a little juice, that you dilute at home. Better Health Channel's example, a blackcurrant cordial with 25% juice reconstituted to directions, comes to about 22.75 g of sugar in a 250 mL glass. The sharp taste is citric acid, shown in the ingredients as "food acid (330)". Reduced-sugar cordials swap sugar for sweeteners but keep the acid; our article on artificial sweeteners and teeth explains why that helps with decay but not erosion. Mixing cordial weaker than the label says cuts the sugar in proportion but still leaves an acidic drink.
Squash and fruit drinks
A fruit drink or squash is juice mixed with water, sugar and food acid, and the percentage of juice on the pack is often small. Better Health Channel's example, a 250 mL pop-top fruit drink with 25% orange juice, carries about 26 g of sugar. Even pure juice is a limited drink: the Raising Children Network suggests no more than half a cup a day, mixed with water or ice. Our guide to fruit juice, smoothies and teeth covers that in detail.
Flavoured and sparkling flavoured waters: sugar-free is not acid-free
Parents ask me about this category most, because the label says "water". Some are not sugar-free at all: Better Health Channel lists a 600 mL vitamin-style water at about 29 g of sugar, and the Raising Children Network warns that flavoured mineral waters can be high in added sugar. Even the sugar-free ones are acidic. The clean, slightly sour bite comes from citric acid (330) or malic acid (296), and carbonation adds a little acid of its own. healthdirect lists sugar-free soft drinks and products containing citric acid, sodium citrate or phosphoric acid among the external causes of dental erosion. In a child, erosion shows as shorter, yellower or see-through edges that chip easily or are sensitive to cold.
How your child drinks matters as much as what
healthdirect notes that frequent sips of an acidic drink increase the time acid is in contact with the teeth, and that enamel stays softer for about 20 to 30 minutes after each exposure until saliva neutralises the acid. A cup of cordial finished with lunch is one acid episode. The same amount sipped from a sports bottle across a school afternoon is a new episode every few minutes. Our article on sports and energy drinks covers the bottles children carry to training.
At bedtime, teeth.org.au advises no food or drink after brushing. NSW Health's Munch and Move program gives parents four rules for sweet drinks: not every day, water them down, serve them with meals rather than through the day, and use a small cup.
Hidden sugar and acid: common children's drinks compared
| Drink and serve | Sugar per serve (Better Health Channel examples) | Acid | Verdict for teeth |
|---|---|---|---|
| Tap water | None | None | Every day, unlimited |
| Plain milk | Natural lactose only | Not acidic | Every day; full-fat under two |
| Cordial made up as directed, 250 mL | About 22.75 g, six teaspoons | Citric acid (330) | Sometimes, with a meal, diluted further |
| Fruit drink, 25% juice, 250 mL | About 26 g, six and a half teaspoons | Fruit acids plus added acid | Sometimes, with a meal |
| Flavoured or sparkling flavoured water, sugar-free | None | Citric or malic acid, carbonation | Occasional, with food, never sipped for hours |
| Vitamin-style water, 600 mL | About 29 g, seven teaspoons | Food acids; check the label | Not a children's drink |
| Sports drink, 600 mL | About 36 g, nine teaspoons | Citric acid | Not an everyday drink |
| Regular soft drink, 375 mL can | About 40 g, ten teaspoons | Phosphoric or citric acid | Rarely |
The single rule: if it is not water or plain milk, it goes with a meal, in a small cup, not every day
The Raising Children Network says that for children aged two and older, tap water and milk are the best drinks, and that soft drinks, cordial, sports and energy drinks have a lot of added sugar and virtually no nutrients. Better Health Channel notes that the Australian dietary guidelines ask everyone to limit drinks with added sugar, cordials and flavoured mineral waters included. Tap water also carries fluoride, a point both NSW Health and teeth.org.au make.
The rest of the rule is damage control. With a meal, saliva is flowing and chewing clears the mouth, so the drink becomes one acid episode rather than many. A small cup limits volume and time. If your child already expects cordial in every bottle, I usually suggest stepping the strength down over a few weeks rather than stopping overnight.
Reading the label, and swaps that work at home
Three things to look for on the pack
First, the "sugars" line per 100 mL; for cordial, check whether the figures are for the concentrate or the made-up drink. Second, the per-serve figure against the cup your child actually uses. Third, the ingredients list, where food acids appear by number: citric acid 330, malic acid 296, sodium citrate 331, phosphoric acid 338. teeth.org.au suggests the Health Star Rating for comparing packaged drinks, though it rates nutrients rather than acid, so a well-rated sugar-free drink can still be hard on enamel.
Swaps that children accept
Cold tap water in a jug with cucumber, mint or a few frozen berries works for most children. If cordial stays in the house, make it weaker than the label suggests, serve it only with a meal, and use a straw so the drink bypasses the front teeth. Afterwards, rinse with water and wait at least 30 minutes before brushing. Brush twice a day with fluoride toothpaste in the right amount for their age, which our guide to children's fluoride toothpaste sets out.
How we approach this at Lumi Dental
A children's check at Lumi Dental looks for the two patterns these drinks leave: early decay between the back teeth and acid wear on the edges. The dentist examines and diagnoses, and the hygiene team of oral health therapists talks with the family about what is in the water bottle and the lunchbox. Where a child is at higher risk, the team may apply fluoride varnish or a remineralising treatment. The whole practice accepts the Child Dental Benefits Schedule for eligible children; see children's dentistry at Lumi Dental. Children who need specialist care are referred to a paediatric dentist.
Questions patients ask
Is cordial bad for kids' teeth?
In the way most families use it, yes. Made up as directed it carries about six teaspoons of sugar per glass plus citric acid. With a meal, well diluted and not every day, it does far less harm.
Is flavoured water bad for your teeth if it has no sugar?
It can still erode enamel. The flavour comes with citric or malic acid, and healthdirect lists sugar-free soft drinks and citric acid additives among the causes of dental erosion.
How much sugar is in a glass of cordial?
Better Health Channel's example is about 22.75 g in 250 mL made up to directions, close to six level teaspoons. Brands and dilutions vary, so compare the per-100 mL figure on your bottle.
Can I give my child diluted cordial?
Occasionally, with a meal and in a small cup. Extra dilution lowers the sugar, but the drink stays acidic, so it should not go in a bottle to be sipped all day.
Can damage from sugary drinks be reversed?
Partly. Very early decay can often be halted with fluoride and a change of habits; our article on reversing early decay explains how. Enamel lost to erosion does not grow back, but a dentist can protect what is left.
Not sure what your child should be drinking? Book a children's check at Lumi Dental in Melrose Park
A children's check lets the team at Lumi Dental look for early signs of erosion and decay and talk through the drinks at home. Families come to Melrose Central from Melrose Park, Ryde, Parramatta, Ermington and Rydalmere, with on-site parking. See our current offers, read about children's dentistry at Lumi Dental, or check eligibility under the Child Dental Benefits Schedule.
Sources
- Better Health Channel: Soft drinks, juice and sweet drinks, limit intake
- Raising Children Network: Healthy drinks for kids and teens
- healthdirect: Dental erosion
- NSW Health, Munch and Move: Water is the best drink for healthy kids
About the author
Dr James Tran is a general dentist at Lumi Dental in Melrose Park. He holds a BDent from the University of Sydney and a Graduate Diploma in Oral Implants, and is a Member of the International Congress of Oral Implantologists (MICOI).
This article is general information only and is not a substitute for an examination and individual advice from a registered dental practitioner. Suitability for any treatment varies from person to person.
