Unpacking sugar’s effects on kids’ brains

Sugar has long been blamed for hyperactivity in children, but research from the University of Adelaide reveals that its effects on the young brain are far more complex and long-lasting.

Globally, the rise in poor dietary habits among children is an escalating concern. As processed foods become standard and fast-food chains permeate our diets, it’s increasingly challenging for parents to maintain their kids’ nutrition. While long-held beliefs from the ‘70s and ‘80s, which blamed sugar for causing hyperactivity in children, have been disproven, there are still significant, lesser-known effects of sugar on the developing brain. Dr. Amy Reichelt, a researcher at the University of Adelaide, is at the forefront of uncovering these impacts, offering new insights into how sugar consumption affects children's cognitive and neural development.

“Many parents continue to reference the outdated research by American paediatric allergist Benjamin Feingold, which falsely linked sugar to hyperactivity in children. However, they remain unaware of the recent findings about unhealthy diets’ impact the developing brain,” Reichelt said.

“I have a particular interest in this area, which is of relevance to the increase in obesity in young people in developed countries.”

Reichelt’s work analyses the effect of over-consumption of sugar on the hippocampus, the part of the brain responsible for memory.

“Excessive consumption of high-fat and sugary foods can have negative effects on neuron function and cause increased levels of inflammation in the brain,” Reichelt said.

This inflammation can be particularly problematic for children, as it can impair their capacity for learning and remembering, a vital factor in healthy development. In fact, people who eat an abundance of junk food perform worse in memory tests than those with a healthy diet.

Additionally, Reichelt says inflammation in the hippocampus can prevent the brain from receiving satiety signals from the gut, resulting in a cycle of over-consumption. As children continue to feel hungry and eat unhealthy foods, inflammation increases further, creating a pattern of over-eating that can become a lifelong behaviour.

“The young brain is malleable because of increased levels of neuroplasticity, so it’s vulnerable to diet-induced changes such as preferences for highly palatable junk foods,” Reichelt said.

“Because these associations are made during critical periods of development, they could become hardwired and endure through life, making it harder to adopt healthy diets.”

Fortunately, Reichelt’s work, which is based on both human and animal neurophysiological measurements, also offers insight into how to encourage better eating patterns. She suggests using fruits to satisfy sweets cravings and making homemade treats using healthier ingredients such as whole grains and natural sweeteners.

However, while a healthy and balanced diet made up of whole foods is the best way to keep kids’ development on track, Reichelt suggests that cutting out sugar completely is not the solution.

“Demonising sugar can have the opposite of the desired effect––resulting in kids wanting it even more,” she said.

“Instead, finding a middle ground can be more effective and sustainable: allow treats on special occasions, like birthdays or holidays, to help children learn that these foods are fine in moderation but shouldn’t be a central part of their diet.”

What’s next?

With a better understanding of how sugar changes the brain and how those changes can lock us into eating patterns that might plague us over a lifetime, we have fresh opportunities to reshape our fraught relationship with food––and to better model this for our children.

Reichelt is pushing her research even further by conducting brain scans of individuals who have issues regulating food intake. She will then analyze these scans to identify neural changes following the implementation of lifestyle intervention plans.

As more research unlocks the underlying causes for our eating behaviours, we move ever closer to a future where we can be confident in the food choices we make for ourselves and our families.