sweets in human evolution are a subject of considerable study among scientists ranging from molecular biologists to cultural anthropologists. Our mammalian and primate heritage predisposes us to liking sweet taste for a number of reasons. See sweetness preference. Mammalian milk contains the sweet-tasting disaccharide lactose (glucose linked to galactose in β1-4 glycosidic linkage). The higher lactose and much higher oligosaccharide content of primate milk makes it even sweeter than cow’s milk or the milk of other dairy animals. We belong to a lineage with a long history of frugivory, defined by a taste for ripe fruit, and like our closely related ape cousins the chimpanzees and bonobos, we tend to love honey. Even early in our evolution our ancestors sought out ripe fruit, favoring the sweetness that develops as plants accumulate sugars in their maturing fruit to entice consumption by seed dispersers. The sweet taste of fruit is mostly due to glucose, the disaccharide sucrose (glucose linked to fructose in α1-2 linkage), and the monosaccharide fructose, which tastes even sweeter than sucrose. See fructose; fruit; and glucose. Most primates exhibit the hedonic “gusto-facial reflex” when tasting soluble sugars. Interestingly, larger primates appear to have lower detection thresholds for sugar.
