Early dietary experience may shape salt preference

December 21, 2011

A study published in the American Journal of Clinical Nutrition shows that infants who have been introduced to starchy table foods—which often contain added salt—may have a greater preference for salty taste than infants who are not yet eating these foods.

In the study, salt preference of 61 infants was tested at both two and six months of age. At each age, the infant was allowed to drink from three bottles for two min each. One bottle contained water, another contained a moderate concentration of salt (1%, about the saltiness of commercial chicken noodle soup) and the third bottle had a higher concentration of salt (2%, which tastes extremely salty to adults). Preference for salty taste was calculated at each age by comparing the amount the infant consumed of a given salt solution to the amount of water it consumed. Thus, if the infant drank more of the 1% salt solution than water, it was considered to have a preference for the 1% solution.

Two-month-old infants were either indifferent to (1%) or rejected (2%) the salt solutions. At six months, salty taste preference of the same infants was related to previous exposure to starchy table food. The 26 infants already eating starchy foods preferred both salt solutions to water, while the 35 babies who had not yet been introduced to these foods remained indifferent to or continued to reject the salt solutions. Reflecting their greater liking for salty taste, the exposed infants consumed 55% more salt during a preference test than did infants not yet introduced to starchy foods.

To explore whether the early effect extended into childhood, 26 of the children returned at preschool age. Mothers completed questionnaires about the children’s dietary behaviors, which revealed that the 12 children who were introduced to starchy table foods before six months of age were more likely to lick salt from foods and also were likely to eat plain salt. These findings suggest that the early dietary exposure was related to an increased affinity for the taste of salt several years later.

“More and more evidence is showing us that the first months of life constitute a sensitive period for shaping flavor preferences. In light of the health consequences of excess sodium intake, we asked if the effect of early experience extended to salt,” said lead author Leslie J. Stein, a Physiological Psychologist at Monell. Stein noted that the study was a correlational and experimental studies need to be conducted to address the question of how children and adults come to prefer high levels of salt in their food.