The human infants' response to vanilla flavors in mother's milk and formula

The mammalian infant experiences a variety of flavors prior to weaning because volatile compounds, such as vanilla, are transferred from the mother's diet to her milk. Following nursing mothers' consumption of vanilla flavor, their infants breast-fed longer and consumed more milk as compared to when their mothers consumed the diluent alone. Consistent with these findings, the bottle-fed infants' responses to vanilla-flavored formula were altered relative to their responses to the unflavored formula. In a short-term preference test, experimentally naive infants sucked more vigorously when feeding the vanilla-flavored formula. In a second test that encompassed an entire feeding, they spent more time feeding initially when the formula was flavored with vanilla. This differential responsiveness to the vanilla-flavored formula was absent following these two exposures to vanilla, however. These data support the hypothesis that flavors, either consumed by the mother and transmitted to her milk or added to formula, are detected by the infant and serve to modulate feeding. They also suggest that experience with a flavor in milk alters the infant's responsiveness to that flavor during subsequent feedings. It is hypothesized that under the natural condition of breast-feeding, infants become familiar with the flavors consumed by their mothers, and such experiences may impact on later food and flavor acceptability and choice.