Why is Sugar Addictive?

By Vicky Zhou '24

Sometimes I eat a bunch of sugar and get a rash. This is mostly due to personal allergies. But imagine if you ate a lot of sugar and a rash appears on your brain. That would be scary, right? Well, that is somewhat similar to what happens when you develop a sugar addiction.

The hallmarks of addiction are tachyphylaxis, physical dependence and withdrawal. This means that an addictive substance has its effectiveness diminished over multiple doses, and when someone stops using it they feel physical symptoms like restlessness or headaches. Addictive substances such as caffeine and heroin usually influence your neurotransmitters, which are chemicals that pass on electric signals between nerve endings in your brain. Well-known neurotransmitters include dopamine, adrenaline, serotonin, and adenosine.

Sugar raises the level of dopamine in your brain. This causes your nerves to get used to much more dopamine than normal. Then when you don’t consume as much sugar, your brain reacts to the lack of expected dopamine, even though it might be the same amount of dopamine as before you consumed sugar. This can cause low moods. Low moods can manifest as depression. This is why some depressed people feel a little bit better when they consume a lot of sugar and immediately worse when it wears off. Slowly you begin to notice that the length of the sugar high begins to be shorter which is not good.

Interestingly, there is a neural circuit that only controls sugar consumption in your brain. Yep, nothing to do with food. Just sugar. Lab rats will seek sugar even if they get electrocuted on the way. It is also very bizarre because people usually don’t distinguish between a food addiction and a sugar addiction. Stress eating might include both normal foods and sugary foods. Think about it. If rats would get electrocuted if that means they can eat sugar, how far are we willing to go? Sugar might be the new oil.

Sources:

Edward H. Nieh, Gillian A. Matthews, Stephen A. Allsop, Kara N. Presbrey, Christopher A. Leppla, Romy Wichmann, Rachael Neve, Craig P. Wildes, Kay M. Tye,

Decoding Neural Circuits that Control Compulsive Sucrose Seeking,

https://doi.org/10.1016/j.cell.2015.01.003.

(https://www.sciencedirect.com/science/article/pii/S0092867415000045)

SUGAR ADDICTION. Scientific American Mind, 15552284, Mar/Apr2014, Vol. 25, Issue 2