Summary: Adolescent rats fed a high-fat diet displayed increased impulsivity and altered decision-making as adults. These “cheesecake rats” were quicker to act on visual cues (indicative of impulsivity) but showed more conservative choices in gambling tasks, opting for smaller, safer rewards.
Genetic analysis revealed changes in their brain’s reward pathway and gut biomarkers, indicating that high-fat diets may interfere with brain development. These findings suggest that diet during adolescence can have long-lasting effects on behavior and neurobiology.
Key Facts
- Impulsivity and Risk: Rats fed a high-fat diet in adolescence showed greater impulsivity and less risky decision-making as adults.
- Brain Development: The high-fat diet altered the mesolimbic reward pathway in the brain, affecting behavior.
- Gut-Brain Link: Modified fatty acid levels in the gut were linked to neurobehavioral outcomes.
Source: ACS
For adults, a diet high in saturated fats and added sugar has been linked to impulsivity and poor self-control. But what role, if any, does diet play in adolescent psychological development?
Researchers report in ACS Chemical Neuroscience that adolescent rodents fed a high-fat diet showed poor control during motor inhibition tasks and conservative decision-making in gambling scenarios as adults.
This information could provide insights into human development.
Diet is one of many factors — like sleep, exercise and substance use — expected to affect an adolescent’s cognitive development and reward-seeking behavior.
Previously, researchers collected evidence that supports the importance of sleep and exercise on behavioral development, but there is limited data about the effects of specific patterns of eating.
So, Santiago Mora and colleagues designed experiments to look at the potential influences of a high-fat diet during adolescence on the actions and choices of adult rats.
For the experiments, Mora’s team fed 20 young rats a high-fat diet of cheesecake (cheesecake rats) and another 20 a nutritionally balanced chow diet (chow rats). When the rodents reached adulthood, the researchers trained all 40 to perform multiple tasks, including a gambling scenario.
These attention and inhibitory-control tasks allowed the researchers to evaluate the animals’ abilities to manage impulsive and compulsive actions and make safe decisions.
Task evaluations revealed that adult cheesecake rats prematurely responded to visual cues (i.e., jumping the gun to get a tasty snack), which the researchers say is evidence of increased impulsive actions.
However, the adult cheesecake rats exhibited less risky decision-making by opting for safer but smaller rewards during gambling scenarios (i.e., no high rolling in casinos) than the adult chow rats.
In additional tests, the researchers identified genetic differences between the cheesecake and chow rats’ prefrontal cortices (one of the parts of the brain that control behavior and personality) and gut metabolism biomarkers.
Briefly, the cheesecake rats exhibited altered function of the mesolimbic pathway — the so-called reward pathway — in their brains and had modified levels of fatty acids in their guts linked to neurological and behavioral outcomes.
The results suggest that a high-fat diet during adolescence could interfere with brain development and affect neurobehavioral outcomes in adulthood.
The researchers say that their data show a high-fat diet in adolescence can provoke long-term changes in impulsive behavior in rats, but they recognize more research is needed to “disentangle the specific mechanisms underlying these intriguing effects.”
Funding: The authors acknowledge funding from the European Regional Development Fund (Fondo Europeo de Desarrollo Regional) and Ministry of Health, Government of Spain (Ministerio de Sanidad, Gobierno de España).
The authors acknowledge the use of generative AI in their scientific writing.
About this diet and psychology research news
Author: Emily Abbott
Source: ACS
Contact: Emily Abbott – ACS
Image: The image is credited to Neuroscience News
Original Research: Open access.
“From Nutritional Patterns to Behavior: High-Fat Diet Influences on Inhibitory Control, Brain Gene Expression, and Metabolomics in Rats” by Diego Ruiz-Sobremazas et al. ACS Chemical Neuroscience
Abstract
From Nutritional Patterns to Behavior: High-Fat Diet Influences on Inhibitory Control, Brain Gene Expression, and Metabolomics in Rats
Impulsive and compulsive behaviors are associated with inhibitory control deficits. Diet plays a pivotal role in normal development, impacting both physiology and behavior. However, the specific effects of a high-fat diet (HFD) on inhibitory control have not received adequate attention.
This study aimed to explore how exposure to a HFD from postnatal day (PND) 33 to PND77 affects impulsive and compulsive behaviors. The experiment involved 40 Wistar rats subjected to HFD or chow diets.
Several tasks were employed to assess behavior, including variable delay to signal (VDS), five choice serial reaction time task (5-CSRTT), delay discounting task (DDT), and rodent gambling task (rGT).
Genetic analyses were performed on the frontal cortex, and metabolomics and fatty acid profiles were examined by using stool samples collected on PND298.
Our results showed that the HFD group exhibited increased motor impulsive behaviors while not affecting cognitive impulsivity. Surprisingly, reduced impulsive decision-making was shown in the HFD group.
Furthermore, abnormal brain plasticity and dopamine gene regulation were shown in the frontal cortex, while metabolomics revealed abnormal fatty acid levels.
