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Sugar addiction, Hits of Dopamine & It's effect on the Brain

Updated: Dec 26, 2021

My inspiration for this blog post came from watching an instagram video where a dad gives his daughter a taste of an ice lolly and the effect it had on her, although humorous to some and cute to others, sparked curiosity and concern in me. Watching this girl, no older than 3, take a hit of sugar from this lolly and within 5 seconds her eyes went huge, her body wriggled and she physically fought her dad to try and get another hit of that sweet sweet sugar.

So what is it that causes this? is it safe? and truly how close is sugar's effect on our brain to the effect of recreational drugs.

We're all lovers of a sweet treat every now and then and it's nothing to be ashamed of. Too much sugar however can lead to problems ranging from Type 2 diabetes and Dental decay. When we have one treat and then can't help ourselves and finish a bag of sweets though, knowing that this isn't great for us from a health point of view, sometimes why do we do this?

It's like our brain is wired to crave more and more...

Our love for sugar comes from our ancestors. An evolutionary trait we developed to tell us when food was ripe or not. With us being scavengers sweet foods we knew would be high energy and so we learned quickly that the fruit and berries we were scavenging made us feel good and fueled us, so our brain quickly updated our reward system. Whenever we learn something new or experience something pleasurable, our brain’s reward system becomes activated. With the help of natural brain chemicals, several brain areas communicate with each other to help us learn and repeat behaviors that improve our knowledge and well-being [1].

This is where Dopamine comes into it...

Dopamine is that chemical which is released when something pleasurable happens to us. For example dopamine is released after sex in order to reinforce that its a good and useful action important for procreation. However our brain can lose its ability to produce dopamine, forcing people to depend on substances to replace what we could once create ourselves. If we start depending on external dopamine, addiction can happen. Substances such as nicotine, cocaine and heroin hijack the users reward pathway in their brain, and this makes the user dependant. Increasing neurochemical and behavioural evidence suggest that sugar addiction occurs in the same way too.

When we consume sugar, the brain produces dopamine and the chemical reaction itself is very similar to the effect of substances like heroin and cocaine on our dopamine. This is because our brains are still in that scavenger mindset, reacting to sugary, high calorie foods, as if they are still necessary for survival. In reality we now have supermarkets full of food, grocery stores full of fruit, vending machines full of snacks. We no longer need to forredge to survive. The brain reacting like this is what leads people to addiction and cravings for sugar.

Ever heard someone say 'I'm so full but I've still got room for desert'. Chances are when you feel like this your body is actually in the mood for a little extra hit of dopamine.

To battle cravings like this, we really have to inhibit our own brains natural response to indulge in these treats. The neurons responsible for the inhibitory process are found in our prefrontal cortex, they release the chemical GABA [2]. However research in rats has shown that eating high-sugar diets can alter the inhibitory neurons. The sugar-fed rats were also less able to control their behaviour and make decisions [3].

We often use rats when studying something like this. Studies where they are deprived of food for 12 hours each day, then given 12 hours of access to a sugar and regular food. After a month of following this daily pattern, rats display behaviours similar to those on drugs of abuse. They’ll binge on the sugar solution in a short period of time, much more than their regular food. They also show signs of anxiety and depression during the food deprivation period. Many sugar-treated rats who are later exposed to drugs, such as cocaine and opiates, demonstrate dependent behaviours towards the drugs compared to rats who did not consume sugar beforehand.

In a 2002 study by Carlo Colantuoni [4] of Princeton University, rats were fed sugar until dependant on it. They then underwent “sugar withdrawal.” This was facilitated by either food deprivation or treatment with naloxone, a drug used for treating opiate addiction which binds to receptors in the brain’s reward system. Both withdrawal methods led to physical problems, including teeth chattering, tremors, and head shaking. Naloxone treatment also appeared to make the rats more anxious.

This suggests that repeated access to sugar over time can lead to prolonged dopamine signalling and an increased dosage is needed for the midbrain dopamine receptors to be activated like before. The brain becomes tolerant and requires something stronger to release the dopamine.

So if we just quit all sugar what effect does this have?

Cutting sugar has different effects on everyone but most people will experience some form of exhaustion, headaches, brain fog and irritability.

Your mood can take a huge hit when you go from being hooked on sugar to completely without it. Your body will be taking its time to get used to these new low levels of glucose, serotonin and dopamine.

Quitting sugar is obviously going to have its positives though once the side effects wear off. One interesting positive is the fact that a lot of people's sleep quality improves when they cut sugar out. This is because foods containing high amounts of refined sugar reduce the amount of 'slow wave sleep' [5]. This is the restorative sleep that consolidates information gained throughout our day and also REM sleep, the dream phase. This means because we're not getting as high quality rest, it's going to have a further effect on concentration, gym performance, nutrient uptake and recovery. It can be a downward slope.

My Take on it all

Addiction to anything is bad, it leads to lack of control, overuse and rapid health deterioration. Sugar clearly has its negatives but so do a lot of things that also have positives too, such as; refined carbs, alcohol, caffeine, fats... The list goes on, and if you look hard enough you can find the negatives for anything. For you to be reading this you have to be using a phone, tablet or computer. It would take you a 2 minute google to find 5 negatives of using these devices. Does that mean that we should avoid them all together? No! How else are you going to read sick blogs like this one?! Same applies to sugar in a way. If you enjoy it, you should educate yourself on the negatives, avoid over consumption and addiction, consume them in moderation alongside a healthy diet and not feel guilty about eating something you like!



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