- A new study investigated how sucralose, a non-caloric sweetener, affects brain signals related to hunger.
- The researchers compared the effects of sucralose to water and sucrose (sugar) among healthy young adults.
- The findings suggest that sucralose may impact the brain in a way that could promote overeating.
At least one in five (20%)Trusted Source adults in the United States have obesity. With so many foods and beverages marketed to people trying to lose weight, scientists wonder how effective they are at satiating appetites.
Some non-caloric sweeteners available include sucralose (Splenda), aspartame (Equal), and saccharin (Sweet ‘N Low). While people often use these when cutting calories, there are possible health effects.
Researchers from the Diabetes and Obesity Research Institute of the University of Southern California conducted a study using magnetic resonance imaging (MRI) scans to determine brain blood flow in the hypothalamus after consuming sucralose, sucrose, or water.
Increased hypothalamic blood flow suggests an increase in hunger signals in the brain.
The study findings indicate that sucralose may trigger strong hunger signals, potentially increasing appetite and leading to overeating when compared to sucrose and water.
The findings appear in Nature MetabolismTrusted Source.
Sucralose is an artificial sweetener that, according to the existing research, has a “sweetness potency approximately 385 to 650-fold higher than sucrose [table sugar] by weight.”
The researchers examined how sucralose impacts people with a group of 75 adults ages 18 to 35 from three different weight categories: healthy, overweight, and obese.
Each participant attended three sessions where they drank either a sucralose-sweetened drink, a sucrose-sweetened drink, or water. The researchers used MRI scans to measure brain blood flow in the hypothalamus.
The hypothalamus plays many roles, including regulating body temperature and hormone release, as well as hunger.
Before consuming the beverage, participants underwent a baseline MRI scan and provided their hunger rating. After finishing the drink, the researchers collected more data after 10 minutes, 35 minutes, and 120 minutes.
Once the researchers concluded all sessions, they compared the MRI scans and the participants’ reports to determine how sucralose impacts brain signaling.
The researchers found that, overall, sucralose not only increased blood flow in the hypothalamus compared to water, but to sucrose as well.
This indicates a stronger hunger-related brain response which could lead to stimulating the appetite rather than suppressing it.
While this was the finding for the group as a whole, when breaking down responses among weight group and sex, the results vary a bit.
People at healthy weights showed a stronger increase in hypothalamic activity after sucralose consumption than after sucrose.
People in the overweight category did not show significant differences in hypothalamic blood flow in response to any drink.
For people with obesity, hunger-related brain activity increased after drinking sucralose compared to water, but not compared to regular sugar.
While sucralose use did not seem to significantly affect hunger responses in people with overweight, the results suggest that it may still significantly impact a large percentage of people overall.
When taking sex into consideration, females showed a stronger response to sucralose over sucrose and water. The researchers believe this supports the notion that women may have a stronger brain response to food cues.
The researchers also noted that their functional connectivity analysis showed that, compared to table sugar, sucralose “significantly increased coupling between the hypothalamus and the anterior cingulate cortex.” This is significant because this area of the brain impacts reward processing and could intensify food cravings.