Scientists believe the colour of your tongue could be an early warning sign of cancer or diabetes.
Harvard researchers say your tongue can actually reveal a lot about your health, whether that’s its appearance, colour or even texture.
In a new article the scientists concluded the tongue should have a round and symmetrical look.
The study says the tongue can also have a white layer.
The study says: “Generally it is a light pink colour, although some may have a purple or brown pigmentation in African, Asian and Mediterranean populations.”
According to Tien Jiang, Odontologist at the Department of Public Oral Health and Epidemiology at the Harvard Medical Dentistry school, the white layer: “comes from a resistant protein called keratin which helps us not to scratch it when we eat.”
The study also concluded the colour of your tongue depends on what you eat, reports The Olive Press.
This, researchers say, is because the bumps on the tongue, known as papillae, absorb colours and residue from the things we eat and drink.
For example curries can containing a lot of turmeric can leave you with a yellow tongue and sweets blue.
The study says there are three main colours that act as a warning sign:
Brown or black
It says: “A brown or black tongue indicates a condition called ‘black hairy tongue’ which occurs when the papillae become too large.
“Normally, these small bumps don’t have much room to grow, but if they do, they can trap bacteria and mixtures of coloured food, leaving a brown or black tint.”
This is says can be caused by smoking, taking antibiotics, mouth dryness, excessive coffee or tea drinking and bad oral hygiene.
White stains or sores
White stains or sores on your tongue is a sign of yeast overgrow, the Harvard scientists found.
It can be caused by conditions such as diabetes, AIDs, taking antibiotics, cancer treatments, using dentures, smoking, or dry mouth.
In severe cases the sores can be a sign of mouth cancer. Similarly if they become yellow, red and painful.
Bright red
This could mean you have a B12 deficiency, scarlet fever or strep throat. The latter two conditions however will be accompanied by a red rash.