Adolescence is a critical time for the developing brain. Neuroscientists at the University of Bordeaux have shown that an unlimited consumption of sucrose in rats during adolescence disrupts brain plasticity, motivation and emotional behavior in adulthood. The observed alterations are corrected by chronic treatment with an antidepressant. These results raise the question of the potential deleterious effects of overconsumption of sugary foods or drinks on brain maturation and mental health in adulthood.
The brain during adolescence is still maturing and therefore particularly sensitive to the environment. However, adolescence is characterized by an often excessive consumption of drugs, alcohol, but also very high sugar foods (sodas, industrial foods). These can represent up to 20% of the daily portion in calories . However, the consequences of overconsumption of sugar during adolescence on the brain remain poorly understood.
Researchers from the INCIA Addicteam team (CNRS) have developed a preclinical project in recent years on the long-term effects of sugar consumption during adolescence. They have shown, in collaboration with NutriNeuro (INRA), that unlimited access to a sweet solution (5%) during adolescence in rats produces a decrease in motivation in adulthood, an increase in Anxiousness and immobility in the forced swim test as well as a decrease in neurogenesis in the hippocampus. These alterations are classically interpreted as a signature of a “depressive” state in pre-clinical models.
In addition, chronic treatment with an antidepressant (imipramine) prevents the appearance of neurobehavioral alterations associated with excessive consumption of sugar water during adolescence. Researchers are now interested in elucidating the neural circuits involved. This work has important societal implications since it suggests that excessive consumption of sugar-rich foods (very rewarding) during adolescence alters the cerebral developmental trajectory and promotes the onset of a depressive state in adulthood .