Smokers do not enjoy their coffee despite the strong, bitter taste of caffeine being easily detected. It seems their ability to taste is impaired by toxic chemicals found in tobacco, even after they have quit smoking.
As part of the study, scientists tested how well 451 volunteers could recognise the four basic flavours of sweet, sour, bitter and salty, as well as the intensity of each taste.
Researchers found that whether the volunteers smoked or not did not affect whether they could recognise salty, sweet or sour tastes but it did have an effect where the bitter taste of caffeine was concerned.
One in five smokers and one in four ex-smokers could not correctly recognise the taste.
However, 13 percent of non-smokers also failed the taste test.Researchers believe the build-up of tobacco in the body could stop taste buds renewing themselves and so harm a person's ability to recognise certain tastes, even after they have stopped smoking.
The findings of the study have been published in the latest edition of the journal 'Chemosensory Perception'.