Bitter taste perception in BaYaka hunter-gatherers

Abstract

AbstractAversion towards bitter tastes evolved across vertebrate species to enable the recognition of harmful plant toxins. Genetic background, mode of subsistence, and dietary factors may explain variation in bitter taste sensitivity between human ecologies. We are the first to examine bitter taste perception within a population at different levels of market-integration, conducting an experiment using phenylthiocarbamide (PTC) and thiourea (Thiourea) infused paper strips amongst the Mbendjele BaYaka hunter-gatherers from Congo. We investigated (i.) prevalence of bitter tasting phenotypes amongst the BaYaka; (ii.) differences between BaYaka who grew up in town and forest camps. We found that 45.1% of BaYaka experience PTC as bitter, and 42.5% experience Thiourea as bitter. There were no sex differences, however bitter tasting phenotypes were significantly more prevalent in town than in forest camps (PTC:64.1%vs35.1%; Thiourea:64.1%vs31.1%). Despite a shared genetic background, we found that BaYaka who grew up in town were more sensitive to bitter taste than those living in the forest, suggesting a developmental component in taste perception. We suggest that the dietary transition from wild to cultivated foods in BaYaka living in town and a decreased use of traditional plant medicine may underlie this variation in bitter taste perception.