Why Some Have a Sweet Tooth and Others Don’t
Slave to the sugar? Blame your genes. (Photo: Getty Images)
If you’re a sugar addict, resisting a pint of ice cream, a bag of gummy bears, or a square of chocolate is no easy task — and it may seem that your weakness is not being able to get enough of the sweet stuff.
Well, according to new research from Monell Chemical Senses Center and the QIMR Berghofer Research Institute, loading up on sugar really is a sign of weakness: Some people have a “weaker” perception to sweet tastes — and may need to pack more sugar to get the same punch as people who have a stronger reaction, study author Danielle Reed, a behavioral geneticist at Monell, tells Yahoo Health.
The human sweet receptor contains a protein called T1R3 — and there are genetic variants that predict how well you perceive sweetness and much you like it, she explains. “People with a particular variant of this receptor seem to like very concentrated sucrose (table sugar) solutions more than people without the genetic variant.”
In the current study, researchers had identical twins (who share almost all the same genes), fraternal twins (who only have about half of the same genes), and non-twins taste natural sugars, like fructose and glucose, and synthetic sweeteners, like aspartame and neohesperidin dihydrochalcone, and rate the intensity of their sweetness.
Why use the twins? “When it comes to sweet taste, genetically identical twins are more similar than non-identical twins,” explains Reed. “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.” This twin-to-twin agreement isn’t as strong when the twins are fraternal. So by using twins, researchers were able to determine that genetic factors — not environmental ones — accounted for about 30 percent of the variance in sweet perception between people. This means being less sensitive to sugar can partially be blamed on nature and not nurture (i.e., being raised with high-sugar foods).
And though researchers suspected that there might be genetic differences when it came to how we perceive natural and artificial sweeteners, “it appears that sweet is perceived through a final common pathway,” Reed says.
So why do sweet genes differ? It could be because of both ancestry and diet, Reed says. “People who live where there is abundant fruit may differ from those who are predominantly or solely meat eaters,” she says. “For instance, cats have lost their sweet receptor over evolutionary time, perhaps because they are meat eaters and need not recognize sweet taste to get their proper diet.”
But unlike hearing and vision tests, there is no well-accepted test to measure taste in the doctor’s office, says Reed. So until that hits the market, know that your taste is “subject to the same laws as your other senses,” urges Reed. “Some people have sensitive hearing or vision and some people do not. Likewise some people have poor senses of taste and therefore require extra sweetness.”
Knowing your own body can help you not only better understand your experience with food but also allow you to make more conscious decisions about what you’re eating. And sweet tooth or not, these 5 Nutritionist Hacks to Make Eating Sugar Healthier are always a good bet.
