Estimated read time: 2-3 minutes
This archived news story is available only for your personal, non-commercial use. Information in the story may be outdated or superseded by additional information. Reading or replaying the story in its archived form does not constitute a republication of the story.
PHILADELPHIA — It may not be lack of self-discipline that keeps you from saying no to that second doughnut.
Scientists say the culprit could be your genes.
A new study out of the Monell Center and the QIMR Berghofer Research Institute — published in the Journal of Twin Research and Human Genetics — revealed that our genetic makeup determines how well we're able to sense sweetness.
To put it simply, some people are much more sensitive to sweet flavors than others — meaning those who don't taste it right away are prone to eating more to satisfy the craving.
#poll
"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 same sweet punch," said study author and behavioral geneticist Danielle Reed in a release.
Researchers asked groups of 243 identical twins, 452 fraternal twins and 511 non-twins to taste different kinds of sugars — both natural and synthetic — and rate them based on sweetness intensity.
By using twins, researchers were able to find out how much of a role shared genetics played in perception of sweet taste — considering identical twins share almost all genes, while fraternal twins share about half.
"If one member of the pair gets a weak signal from sugars or sweeteners, the other twin is more likely to also have a weak signal," Reed told Yahoo. This rang particularly true for sets of identical twins, researchers found.
Using the data collected, researchers determined genetic factors made up a nearly 30 percent difference in how sweetness was perceived. So it's likely nature, not nurture, that ultimately determines how strong our sweet tooth really is.
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 same sweet punch.
–Danielle Reed, study author
"Our findings indicate that shared experiences, such as family meals, had no detectable ability to make twins more similar in taste measures," Reed said.
Another observation was that those who reported a weaker sweetness perception detected little difference in taste between synthetic and natural sugars.
The results of this study could be used to help food manufacturers find more effective ways to use less sugar in their products, researchers said.
"Even though almost everyone — consumers, physicians, and public health officials — wants to decrease the amount of sugar in our diets, right now we have no tool that has the sensory equivalence of sugar," Reed said. "However, if we can understand why some people have weaker sweetness perception, we might be able to adjust this attribute so we could reduce the amount of sugar in foods."
