Harvey’s Blog: How Sugar Impacts Your Brain

Sugar and humans have a rich and intertwined history. The first accounts of its use stem back two and a half millennia. At first, sugar was rare, it was extracted from the crushing of sugar cane and the remaining liquid was then dried and what was left over was the delicious sugar. It wasn’t until the advent of British Empire that sugar entered the realms of the mainstream. The ruling elite in Britain imported sugar from across the globe to satisfy their sweet-tooths, they put it in everything, from Tea to Scones and Jams. This consumption eventually spilt over to the general population and demand grew fivefold between the years of 1710 and 1770.


Fast forward to today and sugar is in everything, you can barely avoid it on an innocent trip to the shops. This article will discuss what happens to the brain when you eat sugar and how we can limit its potentially dangerous impact.


In an experiment (see notes for a link to the study) where rats were given the choice between Cocaine and Sugary water, 94% of the rats chose the sugary water in instead of the Cocaine. The concentration of Cocaine was eventually increased, and the same results were found, and over time, some rats who preferred the Cocaine initially, switched to the sugary water, suggesting there is little bias to stick to the original preferred drug. This is because, when we eat sugar, this triggers our brain to release dopamine. According to our brains, we can literally never have enough dopamine, and if you consider this for a moment, this makes sense. Imagine you are a hunter gatherer; you are walking through the Sahara Desert looking for an animal to hunt with the hope of bringing this back to the tribe for a well-deserved feast. Now, imagine you, as a hunter gatherer, stumble across some Haribos, you eat them, they release dopamine in your brain and then you are given the energy to continue the hunt. This is exactly what the dopamine in our brains is designed to do. The only issue is that we no longer live in a world like that of the hunter gatherers. We live in a very different world, despite this, our brain mechanisms remain connected to this ancestral brain.


Neuroplasticity is a process in which our brains adapt to our behaviours. It is because of Neuroplasticity that we can learn new skills such as driving a car or learning an instrument. When we eat high sugar diets, our brain’s ability to generate new neurons (neurogenesis), which is essential for Neuroplasticity, is inhibited. This affects our ability to learn new skills and can also impact our memory function; over time, this can actually cause the brain to shrink in size.


But it’s not all doom and gloom, here are some changes I have made in my life that have helped me reduce the negative impact of sugar consumption. I am not an expert so please seek the guidance of a healthcare professional before making significant changes to your diet. The first step which helped me was to be conscious of the amount of sugar I was eating in my everyday diet. I tried to cut down on eating high sugary foods by keeping a journal of everything I ate so I could recognise the foods that went under the radar. As exercise helps with neurogenesis, I found exercise to be a great motivator in eating well and it also helps me limit the potential negative impacts of a high sugar diet. Finally, we know stress is also very detrimental to neurogenesis so it’s a good idea to take time to relax and let go of worries.


I am writing this as someone who loves his fair share of chocolate, so try to go easy on yourself when making life improvement decisions, remember it’s okay to fail and it’s okay to treat yourself occasionally.


1.  https://pubmed.ncbi.nlm.nih.gov/17668074/