Public health nutritionist Dr. Carrie Ruxton and her colleague T.J. Bond were aware of the potential dental benefits of tea consumption, but could the fluoride in tea exceed the amounts recommended by UK health agencies?
Ruxton and Bond examined 49 different teabags in three categories: less expensive grocery store brands, those promoted as specialty teas, and decaffeinated teas. The fluoride content was then measured in the dry tea leaves and in cups of tea made from each teabag.
The fluoride content ranged from 0.72 mg to 1.68 mg per cup, with an average of 1.18 mg. Then things got interesting.
There was a clear difference among the three categories. The specialty teas had the lowest fluoride levels (0.72 mg per cup), the less expensive grocery store brands had more and decaffeinated teas had the highest of all. PG Tips, for example, came in with 1.7 mg per cup while Tesco brand was 2.3 mg. Not surprisingly, the dry measurements reflected the same trend: Specialty tea measured 877 mg of fluoride per kg of dry leaf, grocery store brands 1164 mg and decaffeinated tea 1464 mg.
The source of the tea is likely the explanation for these fluoride differences. The tea plants absorb fluoride from the soil and certain locations, like Kenya, have higher naturally occurring amounts of fluoride. Grocery store teabags may more heavily rely on teas from these locations in their blends.
What recommendations result from this data? Researchers state that drinking four cups of tea daily will give the recommended daily amount of fluoride. Excessive consumption of lower quality and decaffeinated teas may contribute to overconsumption of fluoride. Given the high rates of dental problems in the UK, they believe that consumption beginning at the age of four could be helpful. The flavonoids in tea can also kill mouth bacteria that contributes to bad breath, tooth decay and gum disease.
These findings were published in the December 2015 Nutrition Bulletin, a publication of the British Nutrition Foundation.