A high-sugar diet early in life has been shown to harm brain function, but what about low-calorie sugar substitutes? A new study reveals they may take a heavy toll on the developing brain and gut.

The News: In a study published Sept. 13 online in the journal JCI Insight, scientists at the USC Dornsife College of Letters, Arts and Sciences show that adolescent rats that consumed the low-calorie sweeteners saccharin, ACE-K and stevia exhibited long-term impairments in memory.

• The findings align with those from earlier studies in which the researchers show that adolescent rats that consume sugar suffer lingering memory impairment.
• Consuming low-calorie sweeteners also affected metabolic signaling in the body, which can lead to diabetes and other metabolism-related diseases.
• Rats that consumed low-calorie sweeteners as adolescents were less willing to work for sugar as adults, but they consumed more sugar if it was freely available, another factor that might affect the likelihood of developing metabolic disease.

Why It Matters: Advice on what to eat and when to eat it varies widely. Findings from studies like this can help consumers and clinicians make healthier choices throughout the lifespan, say the researchers.

“While our findings do not necessarily indicate that someone should not consume low-calorie sweeteners in general, they do highlight that habitual low-calorie sweetener consumption during early life may have unintended, long-lasting impacts,” said Scott Kanoski, associate professor of biological sciences at USC Dornsife.

What It Means for Humans: While most studies of low-calorie sweeteners focus on one substance and use amounts far exceeding the norm, the researchers made sure the study was in line with real-life conditions for people.