Does Obesity Affect Learning?

Educational failure is a global concern. It includes high dropout rates, low literacy levels, inadequate access to quality education, and disparities in educational opportunities. This problem is more serious in developing countries with fewer economic resources and limited investment in educational programs. However, in developed countries, these issues also exist due to unequal access to education or a lack of sufficient support for struggling students. In these communities, the prevalence of obesity among children, adolescents, and young individuals is increasing as a result of a sedentary lifestyle and high consumption of fast food and highly processed foods. Is it plausible to think that there may be a correlation between two social phenomena?

Obesity is a major issue worldwide

One hundred thousand years ago, hunter-gatherer people, unlike today’s people, were unable to consume enough food multiple times a day. They had to eat limited amounts of roots, grains, and small animals, especially in challenging environments and severe weather conditions. Their bodies should have been able to store more calories as fat to provide energy during times of food scarcity.

Modern humans inherited genes and metabolic systems similar to those of their ancestors, while they consume multiple meals per day. They store fat tissue for times that normally never occur; therefore, obesity has become a problem in today's society.

Obesity imposes a significant burden on today's healthcare systems. The World Obesity Federation predicts that as of 2020, approximately 770 million adults worldwide were impacted by obesity. If no action is taken, this number is expected to surpass 1 billion by 2030. Obesity is associated with several diseases, including hypercholesterolemia, hypertension, coronary heart disease, diabetes, and some types of cancer. However, obesity’s impact on cognitive function and memory is often overlooked. However, recent research has shown that obesity can have a significant role in the decline of cognitive functions and memory.

Obesity has deleterious effects on learning and memory

Many clinicians believe that psychiatric problems are separate from physical diseases. This often comes out of old beliefs regarding the separation of the body and the brain. However, it is wrong to think that body-related diseases have no effect on cognitive functions and the mind. The connection between metabolism and memory is intricate, particularly in relation to obesity, diabetes, and dementia. According to a study [1], adipokines released by the adipose tissue (a form of fat tissue) of healthy individuals have significant physiological impacts on brain functions. However, in obese individuals, inflammatory chemokines originating from adipose tissue disrupt synaptic plasticity and neurogenesis in the hippocampus by crossing the blood-brain barrier.

Research published in 2020 showed that obesity is related to the impairment of short-term memory via the alteration of aromatic amino acids' metabolism by the gut microbiome [2]. This study demonstrated that there are differences in working memory, short-term memory, and the size of the hippocampus and frontal regions of the brain between individuals with and without obesity. They found a consistent correlation between the levels of aromatic amino acids, their byproducts from breakdown, compounds derived from vegetables in both plasma and feces, and short-term and working memory over a period of time. Also, mice experienced a decline in memory scores after receiving a microbiota transplant from humans with obesity.

A study at the University of Alabama at Birmingham found that obesity negatively impacts memory through a mechanism involving the neuroepigenetic dysregulation of Sirt1, a protein involved in the regulation of gene expression. The author discovered that chronic obesity modifies the expression of memory-related genes in the brain through an epigenetic mechanism involving Sirt1 [3].

Among the mechanisms suggested for the effect of obesity on memory and learning, dysregulation of hormones in the body, such as insulin and thyroid hormones, and inflammation are implicated. These inflammatory mediators can cross the blood-brain barrier, influencing the structure and function of specific brain regions.

To summarize, evidence suggests that obesity can negatively affect cognitive function and memory, including in children whose brains are still developing. The relationship between obesity and cognitive function involves various physiological and lifestyle factors. It is crucial for parents, educators, and healthcare professionals to be aware of the cognitive consequences of obesity in children and take proactive measures to promote healthy habits and prevent obesity. This includes encouraging a balanced diet, regular exercise, and reducing sedentary behaviors. Further research is necessary to better understand the mechanisms and potential interventions for addressing the impact of obesity on cognitive function and memory. By addressing obesity in children, we can improve their physical health and support their cognitive development and academic performance.