The research – published in the American Journal of Clinical Nutrition – revealed that children and infants introduced to starchy table foods that contain added salt before the age of six months have a greater preference for salty tastes.
Reflecting their greater liking, the researchers revealed that exposed infants consumed 55% more salt during a preference test than those who were not introduced to starchy foods.
The findings also suggest this early dietary exposure was related to an increased liking for the taste of salt several years later at pre-school age.
“More and more evidence is showing us that the first months of life constitute a sensitive period for shaping flavour preferences,” said Dr Leslie Stein, of the Monell Center, USA.
“In light of the health consequences of excess sodium intake, we asked if the effect of early experience extended to salt,” she said.
Dr Gary Beauchamp, senior author of the research said many international authorities and national governments warn that most people eat too much salt.
“Because it's been so hard to change adult intakes, we asked whether preferences might be influenced earlier in life through experience with salty food ... If so, this may point to the development of public health initiatives that could help people reduce their salt intake," he said.
Food consumption rates and taste preferences of children is of growing concern to industry and policy makers given the rapidly increasing rates of obesity in this age group.
Earlier this year, FoodNavigator reported on a study suggesting that children’s knowledge and consumption of fast food has significant impact on their palate and preference for foods that are high in sugars, salts and fats.
The authors of the previous study – led by Dr Bettina Cornwell, University of Oregon – questioned why food and beverage manufacturers “have come to offer so many products high in sugar, fat, and salt?”
“One possible answer is that it has occurred in the pursuit of taste preference,” they argued, noting that competitive market forces "continually push companies to offer products that are preferred over others.”
In this scenario children’s demand for products containing high levels of salt, is then met by manufacturer supply of foods that contribute to unhealthy eating habits. Conwell said this appears to have become “a self-perpetuating cycle.”
In the new study, Stein and her colleagues measured the salt preference of 61 infants at both two and six months. At each age, the infant was allowed to drink from three bottles for two minutes each: one bottle contained water, another contained a moderate concentration of 1% salt, while the third bottle had a higher concentration of 2% salt.
Two-month-old infants were found to be either indifferent to (1%) or to reject (2%) the salt solutions in all cases. However, at six months, salty taste preference of the same infants was revealed to be associated with previous exposure to table food.
Stein and her team said the 26 infants already eating starchy foods preferred both salt solutions to water, while the 35 who had not yet been introduced remained indifferent to or continued to reject the salt solutions.
To explore whether the early effect of salt preference extended into childhood, 26 of the children returned at preschool age. At this stage, mothers completed questionnaires about the children’s dietary behaviours.
The data revealed that the 12 children 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 – suggesting that earlier exposure had led to a greater liking of salty tastes.
"It's important to note that our conclusions are limited by the correlational nature of the study," said Stein.
"Experimental studies are now needed to address the important question of how children and adults come to prefer high levels of salt in their food," she explained.
Source: American Journal of Clinical Nutrition
Volume 95, Issue 1, Pages 123-129, doi: 10.3945/ajcn.111.014282
“The development of salty taste acceptance is related to dietary experience in human infants: a prospective study”
Authors: L.J. Stein, B.J. Cowart, G.K. Beauchamp