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Food Justice


The surprising ways in which too much sugar is impacting your child’s brain development

The surprising ways in which too much sugar is impacting your child’s brain development
Jelly babies. Image: Amit Lahav / Unsplash

It is fairly common knowledge that too much sugar in one’s diet is a big red flag. But how does it affect children’s development exactly?

The correlation between sugar consumption and obesity, diabetes, dental hygiene, and liver health has been well researched and documented. Similarly, sugar has been linked to a rise in childhood obesity, emotional disorders, and learning issues. The adverse effects of excess sugar on children’s development could be worse than we thought. But how does it affect the brain? Can excessive sugar in a child’s diet impede developmental processes? 

The brain and energy

“Your brain has massive energy requirements,” says Mark Richards, a neurodevelopmental paediatrician whose research focuses on the evolution of children’s brains. In fact, while only making up 2% of the average person’s body mass, the brain accounts for 20% of our energy use. 

There are two major sources of energy for the brain. The first, glucose, is the simplest sugar that we get from carbohydrates. Glucose is generally not consumed in its pure form; rather, we get it from larger sugars, like sucrose (table sugar) and fructose (fruit). 

The second source that our brain derives energy from is ketones; that is, the energy source that our body produces when we metabolize fats. “Your brain is a very fatty organ,” says Richards. For this reason, “fat is an important part of building the structure of the brain. For example, building cell membranes and so on.” Children, who are in the process of development, are “probably utilising ketones in a more significant way than adults.” 

Both glucose and ketones are essential to brain formation and function. But, as Katherine Megaw — a qualified dietician of 23 years who specialises in paediatrics — asserts, “when ketones are used for energy it lowers the temperature in the brain ever so slightly, which makes a big difference in cognitive ability and reasoning. At this temperature, the brain is working very well. Further, when ketones are being used for brain energy source it lifts a fog and increases the acuity of taking in information.” 

She goes on to explain that the composition of breast milk, or what she calls “natures food”, is “extremely high in fat compared to the diet that we advocate to put children on to.” 

A lot of the knowledge that we have about the positive effect of ketones (and conversely, the negative effect of too much sugar) on children’s brains has been gleaned from research done on special needs children (ecliptics, autistic children etc…) Epileptic children on a ketogenic diet (i.e. a high fat, low carb eating plan) showed a significant reduction in seizure frequency. 

Further, Megaw asserts that “in our studies, we have noticed that behavioural elements change. In your autistic population, there are less tantrums.” While the research about this is still at its early stages, the ketogenic diet as a therapeutic tool for children on the autism spectrum is looking quite promising. 

“What we have done is we have extrapolated this into the healthy population,” says Megaw. “If this decrease in sugar is benefitting the special needs population, then surely neurotypical children will have behavioural and learning benefits from more healthy fats and less sugars.” 

What does too much sugar do to the brain? 

Megaw and Richards agree that it is essential to incorporate healthy fats into your child’s diet. But what are the effects of eating too much sugar? 

Luckily for us, the brain is very protective of itself. According to Richards, “the concept of eating too much chocolate and doing physiological damage to your brain is a non-starter.” 

The brain, which is separated from the rest of the body by the blood-brain barrier, a highly selective, semi-permeable border, is very good at controlling what it receives from the body.

“Your brain is very carefully utilising those energy sources,” say Richards, “it sits behind the barrier, not two inches from what is happening outside, and will choose for itself what it needs and what it doesn’t. The brain is never going to overeat or undereat if there is an adequate supply of energy around. 

“The mal effects of prolonged high sugar exposure happen outside of the brain. It’s problems like liver damage and diabetes that cause all the other trouble related to how your cells would normally control the blood-glucose levels.” 

However, the bad news is that while the physical constituency of our brains is very unlikely to be negatively affected by too much sugar, the impact that excessive sugar consumption has on other parts of our body can cause deep psychological issues for adults and children alike. “The physiological impacts of excessive sugar consumption are not the real problem,” agrees Megaw. “It’s the psychological impact that is more difficult to break. The brain itself is not so much altered, it’s the behavioural aspects” 

The severity of these psychological impacts is not to be overlooked and can be particularly traumatic and lasting for children, who are in the process of constructing their physical bodies and mental landscapes.

This, as Richards points out, does in fact affect brain development in children “in more subtle, difficult to define ways.” The chemical composition and structure of the brain may not be directly changed by excessive sugar consumption, but certain bodily and psychological results of too much sugar can certainly negatively alter a child’s mental state and health. 

Obesity and mental health

As we know, excessive consumption of sugar has been closely tied to the prevalence of childhood obesity. In turn, obesity has been linked to a wide variety of psycho-social and emotional problems that can profoundly and negatively alter a child’s experience of the world. The issues that have been associated with obesity include (but are not limited to) depression, anxiety, eating disorders, stress, and low self-esteem. 

Further, research shows that the same emotional and psychological issues caused by obesity make it very difficult to lose weight: a child can get stuck in a vicious cycle which is hard to break. 

“It’s about self-esteem,” relays Richards, “and how children understand their physical worlds. Being overweight limits the way that children might delight in their bodies. How they might enjoy sports and other recreational activities that we know to be good for development.”

Hyperactivity, learning and emotional disorders. 

Megaw explains the link between sugar and hyperactivity in children: “when you eat a refined sugar, it causes a rise in blood sugar, and then an equivalent drop. It’s during the drop when a child will hit a low. The difference between a child and an adult is that when they get the drop, they don’t fall asleep or bum out like we do, they get busy to stay awake, and then they look hyperactive.” 

This has a negative effect on concentration abilities. “If we are feeding kids refined sugar the whole day, they will have multiple ups and downs, which is terrible for focus.” 

The link between excess sugar consumption and ADHD is still at its beginning stages. However, preliminary research seems to point towards a significant correlation. This study, for example, suggests that dopamine receptors (the neurotransmitters that play important roles in pleasure, motivation and learning, whose disruption is thought to be linked to ADHD) might be altered by the constant “ups and downs” caused by excessive and long-term sugar consumption. 

Further, “kids get moody when they are on the sugar low,” explains Megaw, which often results in tantrums and bad behaviour. “They feel better on the highs and need sugar to feel better from the lows.” 

Which leads us to another issue… the problem of addiction. 

Sweet substance addiction

While the nuances of sugar addiction are still up for debate, it is widely known that people can get hooked on the sweet substance. 

“The more you have the more you want because of the feeling you get when you eat sugar,” says Megaw. Sugar boosts serotonin levels and dopamine response in our brains, and can give a temporary feeling of calm, relaxation, and contentment. “This creates an addictive process. More begets more.”

Introducing this cycle to children means that they develop a sugar habit very early in their lives, which can last until adulthood. 

How much is too much? What should we be encouraging or avoiding? 

Some sugar is crucial for children and adults alike, but how much is too much? 

Megaw insists that we should take care not to villainise sugar in general. “What’s important is avoiding very refined sugars [sweets, fizzy drinks, fast food]” (she warns specifically against products with added high fructose corn syrup) “and also balancing sugar and fat intake.” 

She suggests using breastmilk, whose energy is constituted by 40% fats and 45-50% carbs, as a kind of yardstick. “It’s almost equal amount of fats to carbs when it comes to energy production. You want close to a 50/50 balance.” 

Choosing the right kinds of food to fulfil this balance is of utmost importance. In terms of carbohydrates, Megaw suggests that fruits, vegetables, and complex grains (rice/barely/whole-wheat products) are excellent forms of slow-release sugar that will keep your child’s blood-glucose levels constant throughout the day. 

When it comes to fats, “you want a range of fats. Each fat group has different benefits. You want to get fats that have your essential fatty acids, and medium chain fats, which are excellent for brain function. For example, avocados, coconut oil, seeds. Omega-3s are essential too, which we mostly get from fish. You don’t want to be heating these fats at an extremely high temperature.” 

As a rule for all food, “the more natural, the closer to its original form, the better.” 

Tips for how to balance children’s sugar consumption

Thinking about your child’s dietary requirements is something that should probably start before your baby is even born. Richards talks about the first 1,000 days (which are calculated from conception until roughly 2-3 years of age.) “So many processes are critical in these days, from maternal-bonding to growth, to development.” 

It’s essential, during these crucial beginning stages of life, that mothers (before birth) and children (after birth) get enough, and the right kinds of food in order for the child’s brain to properly develop. In terms of sugar consumption, “we can prime children’s metabolism based on the mother’s sugar consumption while the baby is in utero”, says Richards. A child might be more susceptible to excessive sugar eating if a mother has over-eaten during pregnancy. 

Megaw talks about taste-bud training and programming or introducing the right kinds of foods to babies, so they get a taste for them. “It’s not necessary that we train our kids to eat sugars. What we have to train is that they get a taste for good fats and proteins.” 

“For the first three years, it is psychologically safe to not expose your child at all to refined sugars.” 

It’s after the first 1,000 days, however, that things get a little more complicated. “Because we live in a world where treats and fast food are always going to be around,” says Megaw, “after the first three years you need to show your child how to manage those foods in moderation. We are not just made up of our bodies, our taste buds, we’re also made up of emotions and psychologies.” 

Megaw has a method for this that she has used on her own children as well as her clients. This involves packing a mix of sweet and savoury treats (chocolate/chips/cookies etc) into a little box at the beginning of the week and giving it to the child. “That treat box is managed by the child, that’s their world.” 

The child can then eat the treats from the box whenever they want but may not have any more until the next week. “If they eat one every day, then the treats will last the whole week, but if they eat all of them in one day, they have to wait until next week. The child has full autonomy over the treat box. This is what you want to teach them, how to take personal responsibility. It’s about developing good decision-making tools.”

In conclusion

Both fats and carbohydrates play essential roles in providing the brain with energy. In general, however, children are eating too much sugar and not enough healthy fats. 

While the brain, a resilient organ, is unlikely to be directly physiologically affected by the consumption of excess sugar, the bodily and psychological effects of an imbalanced diet can have serious effects on a child. These, in turn, might even have a subtle and cyclical impact on the brain development itself. Obesity, which is linked to behavioural and learning problems like depression, anxiety, and stress, will certainly impede a child’s mental state while fluctuating glucose levels that go hand in hand with consumption of refined sugars, lead to concentration problems and perhaps even more serious issues like ADHD. This is all coupled with the fact that sugar is an addictive substance, and this struggle can last into adulthood. 

It’s important to make sure that your children are balancing healthy fats and carbohydrates. These must come from natural sources and be as varied as possible. 

For the first 1,000 days of a child’s development (from conception to 2-3 years of age), it is psychologically safe to avoid feeding all refined sugars to your baby, and to train them to get a taste for healthy fats and proteins. However, once this period passes, it is then important to introduce controlled amounts of refined sugars into their diets to teach them how to take responsibility and self-moderate sugar intake. 

In general, an excess of refined sugars is detrimental to childhood development, both for the body and the mind. DM/ML 

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