Can Sweet Tooth be a Predictor of Health?

By Karen Kreeger, Director of Communications

For nutritionists and food scientists, creating a personalized plan to lower added sugar intake from artificially sweetened, processed foods may seem unworkable. Perhaps not. Enter Monell postdoctoral fellow May Cheung, PhD who recently published a study describing a simple measure of how much a person likes the taste of sugar – or in her words “how sweet is an individual’s sweet tooth.” Her endeavor will allow researchers to remotely collect information from a diverse population to better understand why some people have a sweet tooth and some do not, and the gradations in between. 

May Cheung, Ph.D.

Understanding how having a sweet tooth is related to health may help us tweak a person’s diet to avoid chronic disease. The appeal of sweetness is a key driver in consuming foods high in added sugars. Overconsumption of sugary foods contributes to increased risk of obesity and related chronic illnesses such as type 2 diabetes and cardiovascular disease. For example, dietitians could use information about an individual’s sweet tooth to create personalized, healthier meal plans. 

Leading health agencies have recommended reducing added sugars in foods. To develop successful treatments or policies to reduce the intake of sugar, it is vital to understand individual differences in how much we like sweetness and how the penchant for it affects what we actually eat. “We know that a person’s diet, exercise, and genetics are related to overall health, but what about a person’s individual food preferences?” said Cheung. “I want to broaden this list by adding chemosensory science – studying taste, smell, and texture – to improve nutrition and overall health.   

The point of collecting sweet liking data is to see if it interacts with the trio of genetics, exercise, and diet to predict health outcomes. For example, a person with an obesity gene who has a sweet tooth may gain more weight than a person with an obesity gene who does not have a sweet tooth. Or, a person who exercises and has a sweet tooth may not gain as much weight as someone who does not exercise and has a sweet tooth. The Simple Sweet Test, as Cheung and colleagues have named the new test, will allow her to test if statements like these are true or not. 

Two years ago, Cheung came to Monell to learn more about measuring human taste and smell, particularly our fondness for high-calorie, sweet foods. Her research is driven by the need for a simple, reliable, and remote-friendly way to measure liking for sweetness for many, many people across different cultures and health statuses. To do this, she is designing and testing a kit to mail to a participant’s home with samples to taste and clear instructions on how to rate what is sent using online software that can be completed on a desktop computer or a mobile device.

Current research on the relationship between sweet taste, diet, and health has been ambiguous. Some investigators have found significant associations between perceptions of sweetness and the intake of sugars, carbohydrates, energy from sweetened beverages, total energy intake, and body composition, while others have found no such links. Differences in outcomes may be due in part to variations in methods and the sweet solutions used to measure sweet perception.

“There are many wonderful studies out there on sweet tooth and how it affects diet and health, but it is difficult to compare the results from these studies because they use different methods,” said Cheung. “I hope to use a data-driven approach to consolidate methods to measure sweet tooth on a large-scale. This study provides insights on how to develop a simpler test for large-scale sampling.”

She compared two common methods for measuring sweet tooth. One method looks at people’s preferred sweetness level by asking them to choose which sample they prefer, the Preference Tracking method. This was developed by Monell faculty Drs. Julie Mennella and Gary Beauchamp and is considered the “gold-standard.” The other method asks people to rate how much they like each sweet sample. She compared the tests when taken at home versus in the lab using a sweetened water solution versus vanilla milk to find the optimal pleasurable concentration, a.k.a., the sweet spot.

Results were similar between the lab and at home in terms of reliability, patterns of individual differences, and degree of liking of the sweet solutions. This means that remote testing for measuring sweet tooth is reliable and feasible. Participants in the study also rated sweetness intensity similarly between lab and home for both sugar solutions.

“I was surprised to see that using both sugar water and sugar vanilla milk provided similar information on sweet tooth,” she said. “I thought how much a person likes sweetness would be dependent on the context. This is because some people may not like sweet water but may like the same level of sweetness in vanilla milk.”

Overall, she found no differences between the preference and liking methods, support for at-home tests, and that sugar water is appropriate for measuring individual differences. She hopes that these results will help sensory and nutrition scientists better measure humans’ love of sugar. “This study provided insights on how to develop a new reliable, accurate, and simple test, that we are calling The Simple Sweet Test. Now I have a better idea of my next steps for expanding this test for large-scale and remote testing.”

Knowing that people like sugar differently, ranging from no sweet to very, very sweet will help design tests for epidemiological and remote studies, to look at the association between sweet tooth and health, and create personalized nutrition plans and diagnostics.