A study on the relationship between type 2 diabetes and taste function in patients with good glycemic control

Type 2 diabetes mellitus (T2DM) has a very high impact on quality of life as it is characterized by disabling complications. There is little evidence about taste alterations in diabetes. Since many individual factors are involved in the onset of diabetes, the purpose of our study is to search a possible link between diabetes and individual taste function. Thirty-two participants with T2DM and 32 volunteers without T2DM (healthy controls) were recruited. Four concentrations of each of the four basic tastes (sweet, sour, salty, bitter), and pure rapeseed oil and water, were applied with cotton pads to the protruded tongue, immediately posterior to its first third, either to the left or right side. The results showed significant differences between groups in the ability to recognize sour, bitter, sweet, and water. Taste scores were lower in subjects with T2DM than in healthy controls, and an age-related decline in taste function was found. The taste function reduction associated with T2DM was not related to gender, disease duration, and glycemic control. In conclusion, it can be hypothesized that a general alteration of taste function can lead patients with type 2 diabetes to search for foods richer in sugars, as in a vicious circle, thus decreasing the likelihood of remission of diabetes mellitus.