Behind the label: Listerine teeth and gum defence

Behind the label: Listerine teeth and gum defence
Pat Thomas 13/01/2009

A little mouthwash to make your tongue and gums feel fresh and clean? Beware, you may be swilling a mouthful of chemicals that will give you more to worry about than bad breath. Pat Thomas reports
We all know that brushing and flossing keep teeth and gums healthy. Nevertheless, in the pursuit of the perfect smile consumers are currently being encouraged ‘to develop a repertoire of oral care purchases’ – in other words, buy more stuff.
Traditionally a mouthwash is an antiseptic gargle that helps remove the bacteria that cause bad breath. But today mouthwashes claim to fight plaque, strengthen teeth, prevent tooth decay and provide all-day freshness as well. Potential mouthwash users are apparently one of the great untapped markets and strategies to exploit this market, particularly in the UK, have paid off. Last year Brits bought 34 million bottles of mouthwash. According to Pfizer Ltd, owners of the Listerine brand, more than 900,000 people in the UK started using outhwash for the first time last year and over half these were purchasing Listerine, the UK’s number one brand. In the US, 147 million bottles of mouthwash fl ew off the shelves, with Listerine accounting for 53 per cent of these sales.

Occasionally, however, marketeers push too far. Earlier this year print ads for Listerine featured a bottle balanced on a scale opposite a floss container, and said: ‘Listerine antiseptic is clinically proven to be as effective as floss at reducing plaque and gingivitis between the teeth.’ A US federal judge ruled this was false, misleading and constituted a public health risk.

Although mostly water, today’s magic bullet mouthwashes are also full of harsh chemicals.

Long-term use of alcohol-containing mouthwashes dries and changes the pH of the mouth and throat and is associated with an increased risk of mouth and throat cancers. If a mouthwash contains a harsh detergent like cocamidopropyl betaine, this compounds the damage. Listerine contains a slightly milder detergent, Poloxamer 407, but its unique qualities – being soluble in liquids at low temperature, but turning into a gel at higher temperatures (ie body temperature) – makes it a film former, keeping other toxic ingredients on the surface of the mouth for longer.

Mouthwashes also commonly contain fluoride, a systemic poison, and this product is no exception. It contains both sorbitol and more worryingly saccharin, which causes bladder cancer in animals.

Finally there are synthetic colours, aromas and flavourings. Flavourings and aromas are basically perfumes. At best they mask odour temporarily; and since they are composed of volatile solvents, they can also alter the basic fl ora of the mouth in the same way as alcohol and may cause dermatitis around the mouth. Combinations of several strong flavourings may be particularly irritating, and methyl salicylate (oil of wintergreen), eucalyptol (oil of eucalyptus) and thymol – even if they are naturally derived – are also highly toxic. Just 10ml of methyl salicylate can poison a child; 30ml can poison an adult.

In addition, bright colours and nice smells mean that children find mouthwashes so intriguing that each year hundreds accidentally get smashed on as little as two ounces. So do adults; earlier this year an American woman was arrested for drunk driving after drinking three glasses of Listerine.