How you perceive sweetness is in your genes, researchers from Australia and the US report in Twin Research and Human Genetics.
"Eating too much sugar is often seen as a personal weakness," says study author Danielle Reed from the Monell Chemical Senses Center in a statement. "However, our work suggests that part of what determines our perception of sweetness is inborn in our genetic makeup."
She and her colleagues compared how 1,901 adolescents and young adults — including 243 monozygotic twin and 452 dizygotic twin pairs and 511 unpaired individuals — perceived the sweetness intensity of the natural sugars glucose and fructose and the synthetic sweeteners aspartame and NHDC.
Though they report that perceived intensity declines with age and that men rated aspartame more strongly than women, they say that how people perceived the sweetness of each sugar is heritable. They report modest heritabilities of 0.31, 0.34, 0.31, and 0.30 for glucose, fructose, NHDC, and aspartame, respectively.
This suggests that a common genetic factor influences the perception of sweetness, they say. They add that this factor explains about a quarter of the phenotypic variance.
"Our findings indicate that shared experiences, such as family meals, had no detectable ability to make twins more similar in taste measures," Reed adds. "The next big question is if, and how, genes and early experiences interact to affect food choice."