Summary: A new study reveals blocking taste receptors leads people to desire sweeter, higher calorie foods. Researchers believe a dulled sense of taste could increase a person’s obesity risk.
Cornell University food scientists have found that people with a diminished ability to taste food choose sweeter – and likely higher-calorie – fare. This could put people on the path to gaining weight.
“We found that the more people lost sensitivity to sweetness, the more sugar they wanted in their foods,” said lead author Robin Dando, assistant professor of food science, whose research has been published online by the journal Appetite.
Nutritionists, researchers and doctors have long suspected a connection between diminished taste sensitivity and obesity, but no one had tested if losing taste altered intake. In his research, Dando temporarily dulled the taste buds of study participants and had them sample foods of varying sugar concentrations.
For the blind tests, the researchers provided participants with an herbal tea with low, medium or high concentrations of a naturally occurring herb, Gymnema Sylvestre, which is known to temporarily block sweet receptors. During the testing, participants added their favored levels of sweetness to bland concoctions.
Without realizing it, they gravitated to 8 to 12 percent sucrose. Soft drinks are generally around 10 percent sugar. “That’s not a coincidence,” said Dando. But those participants with their taste receptors blocked began to prefer higher concentrations of sugar.
“Others have suggested that the overweight may have a reduction in their perceived intensity of taste. So, if an overweight or obese person has a diminished sense of taste, our research shows that they may begin to seek out more intense stimuli to attain a satisfactory level of reward,” explained Dando. This can influence their eating habits to compensate for a lower taste response, he said.
The study showed that for a regular, sugary 16-ounce soft drink, a person with a 20 percent reduction in the ability to taste sweet would crave an extra teaspoon of sugar to reach an optimal level of sweetness, as compared to someone with unaltered taste response.
“The gustatory system – that is, the taste system we have – may serve as an important nexus in understanding the development of obesity. With this in mind, taste dysfunction should be considered as a factor,” Dando said.
Funding: The research was supported by the American Heart Association.
Source: Lindsey Hadlock – Cornell
Image Source: NeuroscienceNews.com image is in the public domain.
Original Research: Abstract for “Participants with pharmacologically impaired taste function seek out more intense, higher calorie stimuli” by Corinna A. Noel,Meaghan Sugrue, and Robin Dando in Appetite. Published online June 9 2017 doi:10.1016/j.appet.2017.06.006
Participants with pharmacologically impaired taste function seek out more intense, higher calorie stimuli
Research suggests a weaker sense of taste in people with obesity, with the assumption that a debilitated taste response increases the desire for more intensely tasting stimuli to compensate for decreased taste input. However, empirical testing of this supposition remains largely absent.
In a randomized, repeated measures design, 51 healthy subjects were treated with varying concentrations of a tea containing Gymnema sylvestre (GS), to temporarily and selectively diminish sweet taste perception, or a control tea. Following treatment in the four testing sessions, taste intensity ratings for various sweet stimuli were captured on the generalized Labeled Magnitude Scale (gLMS), liking for real foods assessed on the hedonic gLMS, and optimal level of sweetness quantified via an ad-libitum mixing task. Data were analyzed with mixed models assessing both treatment condition and each subject’s resultant sweet response with various taste-related outcomes, controlling for covariates.
GS treatment diminished sweet intensity perception (p < 0.001), reduced liking for sweet foods (p < 0.001), and increased the desired sucrose content of these foods (p < 0.001). Regression modeling revealed a 1% reduction in sweet taste response was associated with a 0.40 g/L increase in optimal concentration of sucrose (p < 0.001).
Our results show that an attenuation in the perceived taste intensity of sweeteners correlates with shifted preference and altered hedonic response to select sweet foods. This suggests that those with a diminished sense of taste may desire more intense stimuli to attain a satisfactory level of reward, potentially influencing eating habits to compensate for a lower gustatory input.
“Participants with pharmacologically impaired taste function seek out more intense, higher calorie stimuli” by Corinna A. Noel,Meaghan Sugrue, and Robin Dando in Appetite. Published online June 9 2017 doi:10.1016/j.appet.2017.06.006