• Tests were carried out on 49 tea bags ranging from own brands to decaf
  • Fluoride levels varied with the lowest levels in specialty teas at 0.72mg 
  • This compares to 2.3mg in a Tesco original tea bag and decaf was higher

Drinking tea and bad teeth have long been unflattering stereotypes associated with the English.

But a new study has revealed how a traditional brew can in fact help to strengthen our gnashers – with budget brands coming out on top.

Tests on 49 tea bags found drinking about four cups a day gave people the daily recommended intake of fluoride – known to strengthen tooth enamel and prevent decay.

Cheaper blends and decaffeinated versions were found to contain the most fluoride, which comes from the soil where the tea is grown.

One mug of black blended tea, measuring 240ml, provides on average 1.18mg fluoride, according to the study, published in Nutrition Bulletin.

The figure for single estate/speciality tea, which includes green tea, is lower at 0.72mg.

Tesco Original teabags came out on top, with 2.3mg of fluoride per kg, followed by the supermarket’s Original blend, 2.2mg, and PG Tips standard teabags, 1.7mg.

Decaffeinated blends scored the highest in the study, thought to be as decaf contains stronger flavoured leaves which have had more opportunity to take up fluoride from the soil.

Author of the study, Dr Carrie Ruxton from the industry-backed Tea Advisory Panel, said switching from a sugary drink to tea could improve dental hygiene.

‘Average intakes of tea in the UK are just over two servings daily according to national surveys,’ she said.

‘Increasing this to four cups, would be well within the safe upper limit for fluoride but above recommended levels, helping people to achieve optimal levels of fluoride and protect their teeth.’

However, other studies have claimed the cheaper tea bags can push a person’s fluoride intake over daily recommended levels and put them at a higher risk of bone and dental disease.

European recommendations suggest that an adult does not consume more than 7mg of fluoride per day.

University of Derby scientists discovered that economy blends of tea contained between 75 per cent and 120 per cent of the recommended daily intake.

However, this was looking at large quantities of tea. For example, the study found on average, a litre of cheap supermarket tea contained 6mg mg of fluoride.

Tea is a natural source of fluoride as the tea plant absorbs fluoride present in the soil of tea-producing countries.

The level of fluoride in tea leaves will depend on where the tea is grown, with countries such as Kenya, being particularly good for fluoride-rich soils 

But Dr Ruxton said drinking tea would provide the levels of fluoride recommended for good health and improve the country’s poor dental record.

‘Dental health remains poor in the UK, with decay affecting more than eight in ten adults and a third of primary one children,’ she said.

‘Each adult has an average of seven fillings. As tea is the best natural source of fluoride, switching from a sugary drink to a cup of tea would be an easy way to protect your teeth.

‘Tea may also freshen your breath as plant compounds in tea, called flavonoids, have been found to kill bacteria in the mouth which cause unpleasant odours.

‘Research shows that half the flavonoids in the British diet comes from tea.’

Meanwhile, other researchers have claimed that drinking at least three cups of tea a day can help keep your teeth in good condition, reducing the risk of decay.

A review of existing studies found that black tea helped combat two types of bacteria – Streptococcus mutans and Lactobacillus – that are both associated with tooth decay and gum disease.

Green tea appeared to have a similar effect – and also helped prevent bad breath by neutralising sulphur compounds that contribute to the condition.