Rada, N.M. Avena, and B.G. Hoebel: Daily Bingeing on Sugar Repeatedly Releases Dopamine in the Accumbens Shell (Neuroscience 134 (2005) 737–744)
You’re sitting on a table next to your friend’s packet of Skittles, which has a small open slit in the side. Taking one wouldn’t hurt. The tangy, sweet fruit explodes in your mouth as you devour the candy. You reach for another, telling yourself that it’s your last. Before you know it, the packet is empty.
As it turns out, tasty foods that contain high amounts of sugar, such as Skittles, affect us in similar ways as addictive drugs do. A 21-day study found that for rats that consumed high levels of sucrose (also known as table sugar) every day intermittently, their overall intake increased. Through every day of the experiment, these rats also released a high level of the neurotransmitter dopamine when consuming sugar, which is notorious for its role in reinforcing addictive behaviors. On the other hand, the other groups of rats in the experiment, who weren’t given nearly as much sugar, got over the experiment’s initial excitement after the first two days and stopped releasing higher-than-normal levels of dopamine by the last day.
Shockingly, these innocent sugar-bingeing rats are very similar to humans who experience drug addiction. In the American Psychiatric Association’s Diagnostic and Statistical Manual, addiction is based on a list of symptoms, one of them being tolerance. As tolerance is defined by the capacity to endure increasingly higher amounts of a substance over time, these rats are definitely guilty of developing tolerance after consuming more sugar every day of the experiment. The high amount of dopamine they released is also something they share in common with many drug users, as drugs of abuse often lead to a greater release in dopamine. As one continues to take a substance, their tolerance and dopamine release continues to grow—just as these factors proved to grow over time in the sugar experiments with the rats. Do these similarities imply that sugar is as dangerously addictive as a drug of abuse?
For us humans, the possibility of a sugar addiction is far more dangerous than it is for our rodent friends—sugar is everywhere, including 75% of packaged food in the U.S. As packaged food is the “way to go” for many Americans, we consume up to half a pound of sugar a day. This is significantly much more than we were consuming a few centuries ago, when a single can of soda would be the average American’s sugar intake for an entire year. Are we headed towards a sugar addiction, or are we already there?
Sugar is the active ingredient in an irresistible packet of Skittles and many more treats you might crave. Like the adverse consequences of drugs, high consumption of sugar can also lead to consequences such as cardiovascular disease, liver disease, hypertension, Type 2 diabetes, obesity, and kidney disease. Sugar’s addictive properties and their fatal consequences are something to remain aware of when you want that entire bag of Skittles. Watch how much you consume, or it might end up sucking you in like an addictive substance.
Acknowledgements: Madhvi Subrahmanian, Mother and Nate Taylor, Classmate
American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders: DSM- IV. (4th ed). Washington, DC: American Psychiatric Association.
DiNicolantonio, J. J., & Lucan, S. C. (2014, December 22). Sugar Season. It’s Everywhere, and Addictive. The New York Times. Retrieved February 22, 2016.
Rada, P., Avena, N., & Hoebel, B. (2005). DAILY BINGEING ON SUGAR REPEATEDLY RELEASES DOPAMINE IN THE ACCUMBENS SHELL. Neuroscience, 134, 737-744. Retrieved February 22, 2016