As part of our report on “enhanced” waters, we tested the pH of 19 drinks to see how acidic they were.
A pH of 7 is neutral (for example, tap water); the lower the pH, the more acidic the drink. A pH less than 5.5 increases the risk of dental erosion. The majority of products in our test had a pH below 5.5.
Eight of the drinks contained citric acid, naturally present in oranges and other fruit, and added to beverages as a preservative and for flavour. The most acidic drink was Pure NZ Herbal Sparkling Drink, which had a pH of 2.7. The manufacturer said the drink’s been discontinued but we were able to find old stock in a Wellington supermarket.
Next were Ch’i’s sugar-free offering and OVI Hydration Citrus (it contains ascorbic acid), both with a pH of 2.9. That compares with 2.4 for Coca-Cola.
Five others — VitalZing Water Drops Lemon Lime, Vitasport Water Booster Lemon Lime, Mizone Sports Water Lime, Glaceau Vitamin Water Dragonfruit and Caliwater Cactus Water (it contains lemon juice) — were more acidic than the Keri Orange Juice we tested as a comparison.
The only drinks that had a pH above 5.5 were Pump Water, H2Coco Coconut Water Cocoespresso and Ararimu Valley Alkaline Water. The two plain coconut waters we tested had a pH of 5.4.
New Zealand Dental Association senior oral health educator Dr Deepa Hughes says the acidity of drinks is a hidden danger. “We should drink plain water, not sugary or acidic drinks for hydration. Any other drinks, even if they have ‘diet’ or ‘water’ in their name are best for occasional treats,” Dr Hughes says.
|Keri Orange JuiceA||3.9|
|WATER & WATER-BASED DRINKS|
|Ararimu Valley Alkaline Water||9.8|
|Zero Water Lemon & Lime||Malic acid||4.0|
|Ch'i Herbal Rejuvenation Sparkling Refresher Herbal Sugar Free||Citric acid, ascorbic acid||2.9|
|Mizone Sports Water Lime||Apple cider vinegar, citric acid||3.1|
|OVI Hydration Citrus||Ascorbic acid||2.9|
|Glaceau Vitamin WaterDragonfruit||Citric acid||3.7|
|Sequa Relax||Citric acid||4.0|
|Powerade Silver Charge||Citric acid, sodium citrate||3.5|
|Pure NZ Herbal Sparkling DrinkB||Citric acid||2.7|
|WATER DROPS & BOOSTERS|
|VitalZing Water Drops Lemon Lime||Citric acid||3|
|Vitasport Water Booster Lemon Lime||Malic acid, citric acid||3.1|
|COCONUT & CACTUS WATERS|
|True Nopal Cactus Water||4.6|
|Caliwater Cactus Water||Lemon juice||3.8|
|Chaokoh Coconut Water||5.4|
|O Qua Coconut Water||5.4|
|H2Coco Coconut Water Cocoespresso||7.2|
GUIDE TO THE TABLE PRODUCTS are listed in each category by energy (kJ) (lowest to highest). AThese products were included as a baseline comparison. BThe manufacturer advises this product has been discontinued. pH was tested by an independent laboratory. The lower the pH the more acidic the drink.
Dental erosion, a gradual wearing away of the enamel that can leave your teeth sensitive to hot or cold food or drinks, isn’t the same as tooth decay. Decay is caused by acid produced by bacteria feeding on fermentable carbohydrate, such as sugar, in your mouth. Erosion occurs as the acidic drink washes over the whole tooth surface, which dissolves the tooth enamel in the process. Once the enamel is lost, it’s lost forever.
You can minimise the harm to your teeth by only drinking acidic and sugary drinks during meals when your mouth is producing plenty of saliva to wash the sugar and acid away. You should also drink these drinks quickly — not sip them over a long period of time — or use a straw to reduce direct contact with the teeth.