Ever wondered why your kid yearns for more chocolates than other children? It could be because they need more sugar to get that same sweet taste, a new study suggests.
According to the research from the Monell Chemical Senses Centre in US, sensitivity to sweet taste varies widely across schoolchildren and is partly genetically-determined.
“Some children are 20 times better at detecting sugar than others. As sugar becomes more restricted and even regulated in children’s diets, the less sugar-sensitive children may get less of a ‘sweet signal’ — and, therefore, have a harder time dealing with sugar reduction,” said Danielle Reed from Monell Centre.
The researchers determined the sweet taste threshold — defined as the lowest detectable level of sucrose — of 216 healthy children aged 7-14. Each child was given two cups, — one with distilled water and the other with a sugar solution — and asked to identify which of the two cups had a particular taste.
This was repeated across a wide range of sugar concentrations. The lowest concentration that the child could reliably distinguish from water was designated as that child’s sweet detection threshold (a lower taste threshold meant the child is more sensitive to that taste).
To explore genetic influences on sweet taste perception, DNA from 168 kids was analysed to identify variation in two sweet taste genes known to be related to sweet sensitivity in adults – the TAS1R3 G-coupled protein sweet receptor gene and the GNAT3 sweet receptor signalling gene.
An additional analysis identified variation in the TAS2R38 bitter receptor gene, which is known to be related to individual differences in sweet preferences among children. It was found that the kids who were more sensitive to bitter tastes were also more sensitive to sugar content. In fact, dietary records showed that children with this same bitter-sensitive gene variant consumed a higher percentage of their daily calories as added sugar.
“We were surprised to find that sweet taste sensitivity and sugar consumption were related to a bitter receptor gene,” said Reed.
Using bio-electrical impedance to measure body composition, the researchers found that increased body fat was associated with greater sensitivity to sweet taste.
The findings were published in Journal of Nursing Research.