Field Notes

Dulled Taste Sensitivity May Increase Calorie Consumption

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,” according to lead author Robin Dando, PhD, an assistant professor of food science at Cornell, 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 whether 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 the 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% sucrose. Soft drinks generally are around 10% sugar. “That’s not a coincidence,” Dando says. 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,” Dando explains. This can influence their eating habits to compensate for a lower taste response, he says.

The study showed that for a regular, sugary 16-oz soft drink, a person with a 20% reduction in the ability to taste sweet would crave an extra teaspoon of sugar to reach an optimal level of sweetness, as compared with someone with an 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 says.

— Source: Cornell University


Modest Weight Gain May Increase Long-Term Heart Failure Risk

Gaining even a little weight over time may alter the structure and function of heart muscle, affecting long-term risk of heart failure, according to new research in Journal of the American Heart Association, the open access journal of the American Heart Association/American Stroke Association.

Researchers followed 1,262 adults (average age 44, 57% women, 44% black, 36% obese) who were free from heart disease and other conditions that put them at high risk of heart disease for seven years. Participants had magnetic resonance imaging scans of their hearts and multiple body fat measurements at the start of the study and then seven years later.

Researchers found those who gained weight, even as little as 5%, were more likely to exhibit the following:

  • thickening and enlargement of the left ventricle, well-established indicators of future heart failure;
  • subtle decreases in their hearts’ pumping ability; and
  • changes in heart muscle appearance and function that persisted even after the researchers eliminated other factors that could affect heart muscle performance and appearance, including high blood pressure, diabetes, smoking, and alcohol use.

Conversely, people who lost weight were more likely to exhibit decreases in heart muscle thickness.

Notably, how much a person weighed at the beginning of the study didn’t impact the changes, suggesting that even those of normal weight could experience adverse heart effects if they gain weight over time, researchers say.

“Any weight gain may lead to detrimental changes in the heart above and beyond the effects of baseline weight so that prevention should focus on weight loss or if meaningful weight loss cannot be achieved—the focus should be on weight stability,” says Ian Neeland, MD, senior study author and a cardiologist and assistant professor of medicine at University of Texas Southwestern Medical Center in Dallas. “Counseling to maintain weight stability, even in the absence of weight loss, may be an important preventive strategy among high-risk individuals.”

The results suggest that changes in weight may affect heart muscle in ways that can change the organ’s function. The researchers caution that their study was relatively small and their findings don’t mean that every person with weight gain will necessarily develop heart failure. Further research is needed to determine whether aggressive weight management could reverse the changes, Neeland says.

— Source: American Heart Association