Summary: A new mouse study led by Queensland University of Technology finds that high sugar intake beginning in adolescence increases the likelihood of adult obesity, persistent hyperactivity, and cognitive problems.
Source: Queensland University of Technology
Children and adolescents who consume high amounts of sugar may face a higher risk of long-term weight gain, hyperactivity, and impaired learning, according to a study in mice led by QUT and published in Frontiers in Neuroscience.
Using a validated mouse model, researchers examined the effects of sustained sucrose consumption that began in adolescence and continued into adulthood. The team observed that long-term exposure to high levels of sugar produced significant increases in body weight, pronounced hyperlocomotor responses to novel environments, and measurable declines in both episodic and spatial memory.
Lead author Professor Selena Bartlett, a neuroscientist at QUT, notes that dietary sugar intake in many countries substantially exceeds World Health Organization recommendations. In more than 60 countries, average consumption can top 100 g per person per day—more than four times the WHO guideline of 25 g per day. The experimental results in mice support public health calls to reduce sugar intake, particularly in childhood and adolescence.
“Our mouse model shows that prolonged sucrose overconsumption, starting in adolescence, can alter brain function and behaviour in ways that resemble attention-deficit and hyperactivity disorders,” Professor Bartlett said. “The effects included exaggerated activity in response to novelty and lasting deficits in hippocampal-dependent learning and memory.”
At a cellular level, the study found reduced neurogenesis in the dentate gyrus of the hippocampus, with fewer newborn neurons proliferating and differentiating. These changes in hippocampal biology correlated with the observed memory impairments, suggesting a potential mechanism linking chronic sugar intake to cognitive decline in this animal model.
Professor Bartlett emphasized that while the term “sugar addiction” remains debated, there is growing evidence of shared neural pathways between palatable food consumption and the brain’s reward systems involved in substance abuse. Eating for pleasure and comfort can override homeostatic energy regulation, and excessive intake of sugary foods may contribute to compulsive-like eating patterns.
Co-lead author Dr Arnauld Belmer pointed out that although overall sugar consumption has fallen in some regions since the mid-1990s, obesity rates have continued to climb. The authors suggest this pattern could reflect delayed, long-term consequences of high sugar consumption across the lifespan. In their experiments, reducing daily sucrose intake by four-fold prevented the sugar-induced weight gain and mitigated many of the behavioural and cognitive effects, aligning with WHO recommendations to limit added sugar.
The researchers caution that findings in animal models do not directly equate to human outcomes and that controlled human studies are needed. However, the mouse data indicate a plausible link between early-life overconsumption of sugar—common in Western-style diets—and the later emergence of persistent hyperactivity and neurocognitive deficits.
The study reinforces public health messaging to limit added sugars in children’s diets to reduce the risk of obesity and potential neurodevelopmental consequences. It also highlights the importance of understanding how chronic dietary patterns during critical developmental windows affect brain structure and function.
About this neurodevelopment and diet research news
Source: Queensland University of Technology
Contact: Amanda Weaver – Queensland University of Technology
Image: The image is in the public domain
Original Research: Open access. “Long-Term Overconsumption of Sugar Starting at Adolescence Produces Persistent Hyperactivity and Neurocognitive Deficits in Adulthood” by Selena Bartlett et al., Frontiers in Neuroscience. DOI: 10.3389/fnins.2021.670430
Abstract
Long-Term Overconsumption of Sugar Starting at Adolescence Produces Persistent Hyperactivity and Neurocognitive Deficits in Adulthood
Sugar is a widespread component of modern foods and beverages, and many populations consume far more than the WHO recommends. Using a well-established mouse model, the study evaluated the long-term consequences of sucrose overconsumption beginning in adolescence. Results showed that sustained high sugar intake significantly increased weight gain, produced an abnormal hyperlocomotor response to novelty, and impaired episodic and spatial memory.
Hippocampal-dependent learning deficits were accompanied by reduced neurogenesis in the dentate gyrus—fewer proliferating and differentiating newborn neurons—providing a potential biological basis for the cognitive changes observed. These findings indicate that chronic high sugar consumption during developmental windows could contribute to increased risk of persistent hyperactivity and neurocognitive deficits in adulthood, at least in this animal model.