Brown furry tongue (BFT) is one of the non-lethal consequences of smoking and affects around 360,000 pensioners in the UK. Although it may cause a mildly unpleasant taste in the mouth – much akin to eating quorn – there is no serious or long-lasting damage to the tongue itself, unless you attempt to remove the coating with an electric razor or rotary cheese grater.
In parts of Polynesia, BFT is considered a sign of wisdom, spirituality and fishing skill, and many British pensioners have emigrated to the island of Tuamotu, where they have become judges, minor deities and trawler skippers.
By contrast, BFT is illegal in the Baltic states, with prison terms of up to 12 years for licking a stamp in a public place, using an unprotected straw and supplying tongue and groove floorboards without a permit.
BFT is unrelated to BST, which is British Summer Tongue.