Sugar: A Barrier to Great ideas?

We’ve all heard it: too much sugar is bad for us. Be it on TV, the radio, in books or straight from the doctor’s mouth, we got it: that white delight is to be approached with caution.

Have you ever stopped a moment to consider why we’re told all that? Sugar is food, and food is essential. Plus, it’s present in nature and in all forms. Heck, it is extracted from plants!

Aside from white sugar being the worst for its chemical treatment with sulfur dioxide, it can badly affect your health for many other reasons and in many ways. One of them is by messing with… your brain.

Yes, just as you read: sugar messes with your brain. It has been shown to decrease cognitive function. That ranges from your creativity to your ability to do math and sudoku.

How Sugar Weakens Your Mind

Less Blood to the Brain

Insulin, the main hormone that lowers blood sugar, is a vasodilator. That means that it dilates blood vessels, increasing blood flow to organs, including the brain.

In the case of diabetes (and even before!), excess insulin is produced to keep up with excess glucose being absorbed. Over time, insulin receptors develop resistance to insulin and progressively start responding less to it. Initially, the pancreas will overwork itself to compensate until it can’t keep up anymore. That means less glucose storing and high blood sugar. It also means, if you followed what I said above… less vessel dilation, hypertension and less blood reaching the brain. If the brain isn’t properly perfused, it’s obviously going to work less efficiently.

And this is only the beginning.

It Also Happens Inside the Brain

Addictive drugs are addictive because they increase the release of dopamine inside the brain. Dopamine is the neurotransmitter that, in that organ, is responsible for the reward mechanism. Neurotransmitters are chemical components that are responsible for signal transmission from one neuron to another. Pleasant, stimulating and rewarding activities trigger dopamine release in our heads.

The brain loves dopamine. It loves feeling good.

It also plays a role in mood regulation and cognitive function. It’s the molecule you’re seeing above.

Why am I suddenly talking about drugs and dopamine? Simple.

Sucrose, the fancy name for table sugar, also triggers a dopamine rush.

The more you feed your brain that molecule, the more it’ll crave seconds. Just like an addict, you’ll need your fix of candies. “It’s all in your head”, literally.

A scientific study showed that sucrose-dependant rats released more dopamine every time they drank a 10% sucrose solution. They also drank more of it every time they were given access to it. Additionally, they had a delayed acetylcholine response.

Why this other fancy chemical name? Well, acetylcholine is thought to play a part in the satiety signal. Therefore, delayed acetylcholine signal = delayed satiety and more important food intake during meals.

Addictive behaviors increase dopamine release, we got it. What’s that got to do with sudoku?

Well, much like the insulin ones, dopamine receptors get tired of working overtime. They become desensitized. Like Psychology Today put it: “We know from dozens of studies that drug or alcohol use itself leads to a reduction in dopamine receptor density, or at least dopamine receptor activation, because those receptors tend to burn out or become desensitized when we keep bombarding them with fun stuff.” In short, too much dopamine leads to either less receptors or less sensitivity on their part, and a need for higher doses in order to be stimulated. That is know as tolerance.

Another study, based on sham feeding (feeding with the ingested food being evacuated from the stomach, therefore not making it all the way through the digestive system) found that the taste of sugar alone was enough to increase dopamine release. And yet another one found that cognitive functions were more importantly decreased by sugar-sweetened beverages than by artificially sweetened ones. That’s not to say that artificial sweeteners are generally preferable.

The Bottom Line

Sugar is essential. It’s a quick source of energy and a trigger for dopamine release, which is actually not a luxury.

However, we should be more mindful of how much we consume and where we consume it from. A little occasional processed treat can’t hurt, but we should prefer healthier sources, such as fruits, complex carbs (think grains, especially whole grains), milk (lactose is a sugar), etc.

Now, how to overcome sugar addiction? That’s a theme for another post.

Linked & Additional Resources

https://physoc.onlinelibrary.wiley.com/doi/full/10.1113/jphysiol.2012.234328

https://www.tandfonline.com/doi/abs/10.1080/1028415X.2019.1580919

https://pubmed.ncbi.nlm.nih.gov/15987666/

https://pubmed.ncbi.nlm.nih.gov/16460879/

https://www.tandfonline.com/doi/abs/10.1080/1028415X.2019.1580919

https://www.psychologytoday.com/us/blog/addicted-brains/201308/when-the-thrill-is-gone-reward-deficiency-syndrome