(Relaxnews) - Scientists from the Monell Chemical Senses Center in Philadelphia, PA have found children who enjoy sweet tastes also enjoy salty tastes, and prefer such tastes more than adults.
The study, which was published in the journal PLOS ONE, suggests that biology contributes to our enjoyment of sweet and salty foods, which are high in calories and sodium, respectively.
Lead author Julie Mennella, PhD, a biopsychologist at Monell and her colleagues tested 108 children between 5 and 10 years old, as well as their mothers, for salty and sweet preferences. The same testing method was used for both, who sampled "broth and crackers that varied in salt content, and sugar water and jellies that varied in sugar content." Mennella's method is designed to scientifically determine taste preferences, even in young children. This is accomplished by having them compare and pick their favorites concerning two different levels of a particular taste, then compare that favorite with another taste over and over "until the most favorite is identified."
The research team also asked mothers and children to list foods and beverages they consumed in the past 24 hours in order to gauge daily sodium, calorie, and added sugar intake. Subjects provided a saliva sample genotyped for a sweet receptor gene, and a urine sample that measured levels of Ntx, a marker for bone growth. Weight, height and body fat percentage were measured in each subject as well. Two-thirds of the children taking part in the study were overweight or obese, and consumed twice the recommended levels of sodium. Their added sugar intake was about 20 teaspoons, or 300 calories, daily.
After analyzing data from the experiment, researchers found sweet and salty preferences were linked in children, and were generally higher than adult preferences. They also found children's taste preferences "related to measures of growth and development," as children who were tall for their age favored sweeter solutions, while children with higher amounts of body fat went for saltier soups. An indication that higher sweet preferences relates to bone growth spurts was also found, however this confirmation requires further study with a larger group of children.
"Our research shows that the liking of salty and sweet tastes reflects in part the biology of the child," noted Mennella. "Growing children's heightened preferences for sweet and salty tastes make them more vulnerable to the modern diet, which differs from the diet of our past, when salt and sugars were once rare and expensive commodities."
A link between sweet and salty preference was found in adults as well. Unlike with the children, the adults' sweet receptor genotype correlated to the most-favored sweetness level. "There are inborn genetic differences that affect the liking for sweet by adults," says collaborator Danielle Reed, PhD, "but for children, other factors -- perhaps the current state of growth -- are stronger influences than genetics."
With US children currently consuming much higher amounts of salt and sugar than recommended and The World Health Organization, American Heart Association, US Department of Agriculture and Institute of Medicine all recommending significant decreases in sugar and salt intake for children, understanding the basic biology that drives the desire for sweet and salty tastes in children can play a role in "developing more insightful and informed strategies for promoting healthy eating that meet the particular needs of growing children", Mennella remarked, regarding the implications of her research.
