Popular artificial sweetener sucralose could disrupt appetite and make users hungrier than if they consumed sugar, a new study found.
Researchers from the University of Southern California discovered that sucralose increased activity in the hypothalamus, the region in the brain known for regulating appetite and body weight.
Although previous studies indicated a link between artificial sweeteners and obesity, the exact mechanism by which they affected hunger remained unclear.
In the new study, published in the journal Nature Metabolism, researchers tested how 75 participants – evenly split between male and female and by weight – responded after consuming water, a drink sweetened with sucralose, or a drink with regular sugar.
Each participant was tested with sucralose, sugar and water on three separate occasions, allowing researchers to look for differences within and between individuals.
They collected fMRI brain scans, blood samples and self-reported hunger ratings from participants before and after they consumed each drink.
Researchers found that sucralose tended to increase hunger as well as activity in the brain’s hypothalamus, especially in people with obesity.
The artificial sweetener was also found to alter the way the hypothalamus communicated with other regions of the brain.
Researchers also observed that, unlike sugar, sucralose did not increase blood levels of certain hormones, like insulin and GLP-1 which create a feeling of fullness.
Female participants showed greater brain activity changes compared to male participants, suggesting that sucralose could affect the sexes differently.
“The body uses these hormones to tell the brain you have consumed calories in order to decrease hunger. Sucralose did not have that effect,” Kathleen Alanna Page, a co-author of the study, said.
“If your body is expecting a calorie because of the sweetness but doesn’t get the calorie it’s expecting that could change the way the brain is primed to crave those substances over time.”
Researchers also found that consuming sucralose led to increased connectivity between the hypothalamus and brain areas involved with motivation, sensory processing and decision-making.
Based on these findings, researchers concluded that sucralose could impact cravings or eating behaviours. “These findings suggest that non-caloric sweeteners could affect key mechanisms in the hypothalamus responsible for appetite regulation,” the study noted.
Researchers, however, were unsure if the observed changes in brain and hormone activity had any long-term effects. They said further studies in a larger population, including assessment of participants’ body weight and eating behaviours, could help determine this link.
