Smokers’ taste buds do not allow them to taste bitterness of coffee

Though conventional pairing has cigarettes and coffee going together, researchers has found that the toxic chemicals in tobacco may hamper taste bud regeneration, resulting in smokers not being able to adequately taste the bitterness of their regular cup of coffee.

The researchers note that tobacco's chemicals are already known to cause a loss of taste in smokers, as well as structural changes to the fungiform papillae of the tongue - where taste buds are found. What has been unknown is to what extent smokers' taste range is affected, whether it returns to normal upon quitting smoking and if so, how long that takes.

Taste buds are largely responsible for conveying sweet, sour, bitter, salty and metallic sensations. To further investigate the changes in taste buds caused by smoking, they tested the ability of 451 study participants to recognize and rate intensity of the four basic tastes - sweet, sour, bitter and salty.

Dividing the participants into three groups (smokers, non-smokers and former smokers), the team conducted the voluntary tests during three separate and consecutive "World No-Tobacco Days."

A person's ability to recognize salty, sweet or sour tastes was not influenced by smoking status, the researchers say. However, smoking status did affect their ability to taste the bitterness in caffeine. While bitter receptors in the tongue are normally able to detect this sensation in even low concentrations, nearly 20% of smokers were not able to correctly identify the taste. Of the former smokers, 26.5% were not able to identify the taste, while only 13.4% of the non-smokers were unable to correctly identify the bitter samples.

The perception of bitter taste should be examined more closely, both as a tool for smoking cessation or for preventing smoking initiation. More generally, it should be worthwhile to consider the role of chemosensory perceptions in smoking behavior. The team believes the accumulation of some tobacco products in the body could impede taste buds regenerating, which could still affect a person's ability to recognize certain tastes after they have quit smoking.