Do you have a sweet tooth? Researchers from the Monell Chemical Senses Center in Philadelphia have suggested that you can blame your genes for the extra servings of desserts. The team found that just as people born with a poor sense of hearing may need to turn up the volume to hear the radio, people born with a weak sweet taste may need an extra teaspoon of sugar in their coffee to get the right punch.
The researchers found that a single set of genes affects a person's perception of sweet taste, regardless of whether the sweetener is a natural sugar or a non-caloric sugar substitute. Study author Danielle Reed, behavioral geneticist at Monell said, "Our work suggests that part of what determines our perception of sweetness is inborn in our genetic makeup."
To reach this conclusion, the research team tested 243 pairs of identical twins, 452 pairs of fraternal twins and 511 unpaired individuals. Each study participant tasted and then rated the intensity of four sweet solutions- fructose, glucose, aspartame, and neohesperidine dihydrochalcone (NHDC).
The results revealed that genetic factors account for approximately 30% of person-to-person variance in sweet taste perception. Participants who perceived the natural sugars as weakly sweet experienced the sugar substitutes as similarly weak.
The authors said, "This suggests that there may be a shared pathway in the perception of natural sugar and high-potency sweetener intensity. Understanding the genetic differences that affect an individual's perception of sweetness may eventually help food manufacturers reduce the amount of sugars and sweeteners they add to food."
The study also found little evidence for a shared environmental influence on the perception of sweet taste. Assuming that twin pairs took part in communal meals during childhood, this result challenged the common belief that access to foods high in sugar may make children insensitive to sweetness. Reed explained, "Our findings indicate that shared experiences such as family meals, had no detectable ability to make twins more similar in taste measures."
The study is published in Twin Research and Human Genetics.