Influences of weight, age, gender, genetics, diseases, and ethnicity on bitterness perception: a narrative review of current methodological aspects

Abstract\ud \ud Background\ud Bitterness perception seems to be related to an enhanced intake of dietary fat and to a tendency to the development of diseases such as obesity. However, the exact factors for this possible contribution still need to be better investigated. So, gustatory perception of the bitter taste is a promising area of study because of its importance regarding food choices and consequently feeding behavior. Therefore, this short review focused on recent papers reporting correlations between bitter taste, anthropometric variables, obesity and other chronic diseases, age, gender, ethnicity, and genetics.\ud \ud \ud Methods\ud A survey was performed in MEDLINE (PubMed) and Scielo from September 2015 to January 2017. Only review articles, observational studies and clinical trials published in English and Portuguese over the last 15 years which met the objectives of the present study were considered. A total of 40 papers were evaluated.\ud \ud \ud Results\ud Two papers showed a positive correlation between bitter taste and obesity, one indicated that this correlation is influenced by the subject’s age, one suggested a negative correlation, and two found no association. Age seems to be negatively correlated with the bitterness perceived, and female gender was associated with a stronger perception of bitterness. Genetics, mostly due to differences in TAS2R38 expression, influences sensitivity to the bitter taste, feeding behavior and also alcohol intake. Ethnicity, not only the subject’s phenotypic or genotypic characteristics, seems to play a role in taste perception and nutritional diseases.\ud \ud \ud Conclusions\ud Age, gender, genetics and ethnicity seem to play a role in bitterness perception. Data about associations between bitterness perception and anthropometrics are conflicting.AA received a scholarship from the São Paulo Research Foundation - FAPESP, process 2015/00403-3. SS received a scholarship from the National Council of Technological and Scientific Development - CNPq (PIBIC). JSM received a productivity scholarship from the National Council of Technological and Scientific Development – CNPq, process 304127/2009-4. The other authors have nothing to declare