Diets Rich in Fat Correlated with Notable Brain Alterations
A new study has shed light on the potential long-term effects of high-fat diets during adolescence, revealing that such diets can lead to alterations in brain function and behaviour in both rats and humans.
In rats, adolescent rats fed a high-fat and high-sucrose (HFHS) diet exhibited reduced numbers of fast-acting parvalbumin-positive (PV+) interneurons and perineuronal nets (PNNs) in the medial prefrontal cortex (mPFC), which disrupts neuroplasticity. High-fat diets also reduced brain-derived neurotrophic factor (BDNF) levels in the hippocampus, negatively impacting learning and memory.
The HFHS diets activated the mesocorticolimbic pathway, encouraging further reward-seeking behaviour. This was associated with upregulation in D1 dopamine receptors and increased neuronal activation in the prefrontal cortex. The diets also promoted impulsivity, with males showing greater and more persistent effects compared to females.
Adolescent rodents exposed to HFHS diets for short periods exhibited anxiety-like and depression-like behaviours, which were not observed in adults.
In humans, children with obesity showed lower cognitive performance, with reduced fluid reasoning. Brain scans revealed thinner cortical thickness and damaged white matter integrity. High-fat diets may contribute to similar changes in brain structure and function, though direct human studies are limited.
High-fat diets can lead to increased reward responsivity to food, associated with higher body mass index (BMI). This suggests potential long-term impacts on reward signalling similar to those observed in animal studies.
While specific impulsivity studies in humans are less direct, the activation of reward pathways and potential for increased impulsivity due to high-fat diets are plausible based on animal models and human brain function studies.
The research raises questions about how similar dietary habits might affect human adolescents, highlighting the critical role of diet during adolescence, a period when the brain's plasticity makes it sensitive to environmental factors.
The findings also suggest that understanding how specific nutrients influence the brain's development and functioning could lead to targeted interventions. For instance, supplementing diets with omega-3 fatty acids has shown promise in reducing impulsive behaviours.
The study used various behavioural tasks to investigate how high-fat diets affect different aspects of impulsivity. Researchers have found that high-fat diets can alter the brain's reward systems, influence gene expression, and affect how the body metabolizes fats.
The impact of high-fat diets extends beyond the brain and can influence energy signalling in the body. The study's findings underscore the importance of diet during adolescence and the potential long-term consequences of unhealthy eating habits during formative years.
In this research, it is suggested that high-fat diets during adolescence could impact not only physical health but also mental health, as witnessed in reduced neuroplasticity and altered brain function in both rats and humans, pointing towards the need for increased focus on health-and-wellness and mental-health concerned with fitness-and-exercise and nutrition during the adolescent years. Furthermore, understanding the role of specific nutrients in brain development and function, such as omega-3 fatty acids, could potentially lead to targeted interventions aimed at improving cognitive performance and reducing impulsive behaviours associated with high-fat diets.
