Bottled water gives the brush-off to tooth decay

by Richard Gray

Scientists find minerals have beneficial effect on dental hygiene

Drinking bottled mineral water protects teeth from the damage caused by sweet and acidic food, according to remarkable new research by a team of Scots scientists.

As the debate rages over whether bottled water tastes any better than tap, the researchers have discovered that the simple act of drinking two glasses of mineral water a day offers "significant" protection against tooth erosion.

The Dundee University team believe bottled water helps remineralise the enamel outer layer of teeth, which is vulnerable to erosion.

The research, which was funded by the Scottish Executive, has astounded dentists, who have longed believed drinking water had no effect on teeth whatsoever.

The findings are good news for the UK's £2bn-a-year bottled water industry, which is under pressure after a report by the Drinking Water Inspectorate found that UK tap water is among the safest and purest in the world.

Campaigners claim bottled water firms are ripping off consumers by asking them to pay up to 95p a litre for a product little better than can be taken from the tap.

But Dr Graham Chadwick, who led the study at Dundee's dental school, believes mineral water can supply vital nutrients to teeth that help them resist wear.

In a comparison of 16 different factors thought to influence the destruction of tooth enamel, he discovered that only sparkling mineral water and brushing with fluoride toothpaste provided protection to teeth.

"This was a chance finding for us," Chadwick said.

"The high mineral content seems to help remineralise teeth by replacing essential minerals in the enamel that get removed when they are exposed to acid."

The study examined the eating, drinking and brushing habits of 250 school children aged between 11- and 13-years-old and compared them with the level of dental erosion over an 18-month period.

The researchers used a unique method for measuring the level of erosion in the children's teeth by applying a technique more commonly used to monitor damage to Britain's coastlines.

They scanned impressions taken from the children's mouths to create a digital map of their upper front teeth which were compared with maps taken 18 months later to measure tiny changes in size due to erosion.

The study found that most risk factors - such as a bedtime drink, drinking fruit juice and eating after brushing - had a negligible direct effect on tooth erosion.

But it found that those children who drank mineral water suffered less erosion than those who did not, even though both groups drank sugary soft drinks.

And while the study focused on the effect of sparkling mineral water, Chadwick claims the effect would be the same for still mineral water. It is thought even tap water could have a positive effect, but that would depend on the levels of minerals it contained.

Indeed the findings may weaken calls for fluoride to be added to Scotland's water supplies as they suggest that tap water is already helping to protect the public's dental health without the additive.

Although dentists claim adding fluoride to water is the best way of improving the nation's dental health record, the move has met opposition due to health fears and the concept of "mass medication".

Chadwick said: "While you would not expect water to cause erosion of teeth, it is surprising that it should actually reduce erosion.

"Although our study looked at fizzy mineral water, there is no reason why the same effect would not be seen in still mineral water.

"In relation to tap water, I would certainly advocate that in order to prevent erosion people simply drink more tap water throughout the day rather than potentially erosive drinks."

He added that both adults and children could benefit from remineralisation, although his study was on children's teeth.

Erosion is caused by acid from carbonated drinks, fruit juices and other foods that wear down enamel, leaving teeth sensitive and prone to damage.

Scotland has one of the worst dental health records in Europe with almost half of all 11-year-olds suffering from decay in their adult teeth.

The latest study, funded with a £100,000 grant from the Scottish Executive Chief Scientist's Office, is now being examined by health officials.

A spokesman for the Executive said: "Current advice recommends drinking still water as there are concerns about dental erosion linked to fizzy drinks. However, we carefully monitor new research and keep our advice under review."

Dentists expressed surprise at the findings and called for further research.

Previous studies have found that the small levels of carbon dioxide that produce sparkling water also leave it slightly acidic.

Dr Chris Deery, a consultant in paediatric dentistry in Edinburgh, said: "There is a debate in the dental profession about whether carbonated mineral water causes erosion or not.

"I am part of the group that did not think it was harmful, but I am surprised that it is protective. It would great if we could encourage children to drink more mineral water rather than sugary soft drinks."

Dr Steve Creanor, from Glasgow University, added: "Fizzy mineral water is certainly better than drinking fruit juices and sweetened soft drinks, but there is not enough evidence yet to say it conveys protection."

Resources:
Scotsman.com