How Does Excess Sugar Affect the Developing Brain Throughout Childhood and Adolescence? A Neuroscientist Who Studies Nutrition Explains

Diet, brain and function

Certain dietary components such as amino acids, which form the basis of proteins, act as precursors for brain chemicals. Amino acids also play important roles in mood, learning and cognitive functions.

Like car engines that require the proper fuel to run efficiently, brains also require an adequate diet for optimal functioning. The brain is made up of nerve cells, or neurons, and housekeeping cells, called glial cells. Although these two types of brain cells have different metabolic needs, glucose is the primary source of energy for both.

Despite the fact that the brain accounts for only 2% of human body weight, it requires about 20% of the human body’s energy needs to perform all of its functions, including learning, memory and cognitive processes. Research suggests that this number is even higher in children whose brains and bodies are developing rapidly.

Brain function and growth are regulated by brain chemicals known as neurotransmitters, which should dictate the architecture of brain development. Depending on the stage of brain growth, an imbalance of critical neurotransmitters may cause a myriad of ailments, affecting learning, mood and behaviors.

Similarly, a low-quality or imbalanced diet, such as one high in processed sugar, can throw off the brain’s chemical equilibrium.

Excess sugar puts the brain in overdrive

Because glucose is the primary source of energy to the brain, too much sugar can put it into an overdrive mode. When the brain is overstimulated, it can lead to hyperactivity and mood swings. However, these behavioral changes are only the short-term consequences. Some evidence suggests that this brain hyperactivity in adolescents is linked to cognitive deficits in adulthood.

Sugar also has an addictive effect because it stimulates neurons in the brain’s reward system, known as the limbic system. When activated, the limbic system generates high emotions such as pleasure, which reinforces further sugar consumption.

In addition, within the limbic system there is a tiny structure called the amygdala, which processes emotional information. Overactivation of the amygdala is associated with exaggerated emotions such as fear and anxiety.

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Research suggests that there is a strong relationship between high sugar consumption, altered behaviors and poor emotional regulation. Although sugar intake may boost mood momentarily, chronic sugar consumption has been linked with increased risk of mental health problems.

Studies in lab animals also suggest that high consumption of sugar hinders learning and memory. Interestingly, daily intake of sugar-sweetened beverages during teenage years is associated with worsening of performance on a learning and memory task during adulthood. The researchers of that study suggest that this impairment could be due to alterations in gut bacilo.

Considering the mounting body of evidence, the seemingly atrayente sweetness of sugar can translate into a bitter outcome for the developing brain.

Lina Begdache, Assistant Professor of Nutrition, Binghamton University, State University of New York.  

This article is part of a series examining sugar’s effects on human health and culture. Read the series at theconversation.com.

This article is republished from The Conversation under a Creative Commons license. Read the innovador article.