Can sugar make you dumb? I wish I would have thought about this question before studying for my last chemistry exam. It was around 9 p.m., and I was in the newly-remodeled LSA building on campus. It was getting to that point in the night when you keep re-reading the same problem over and over again and seem to retain nothing. I needed something to wake me up. I decided to check out the self-service cafe in the lobby for a study snack to get me through the next practice exam. I was torn between Sour Patch Kids and dried apple chips. Faithfully, I chose the Sour Patch Kids since they had succeeded in giving me that late-night sugar boost in the past.
The brain uses sugar in the form of glucose as its main food source. When you have low blood sugar, your brain loses its energy to function. I knew my brain needed some food, but was I overdosing on sugar by choosing the Sour Patch Kids?
According to the American Heart Association, the maximum daily sugar intake for men is 36 grams and for women is 25 grams. We are all overdosing on sugar. The 2 tablespoons of Nutella that you spread on your toast this morning contained 21 grams of sugar in it; for females, that is 84 percent of your daily sugar intake already wasted on one piece of toast.
According to research performed by Fernando Gomez-Pinilla, a professor of neurosurgery at the David Geffen School of Medicine at UCLA, a long-term high-fructose diet affects the brain’s ability to learn and remember information. Gomez-Pinilla studied how a variety of genes in the brain can be damaged by fructose.
In Gomez-Pinilla’s study, rats were trained to escape from a maze and then divided into three groups. The first group drank fructose and had no Docosahexaenoic acid (DHA) in their diet. DHA is a type of omega-3 fatty acid that is essential in the brain. The second group drank fructose water and was fed a DHA-rich diet. The third group drank non-fructose water and had no DHA-rich diet.
When the rats were put through the maze again, the rats that drank fructose water with no DHA-rich diet took twice as long to complete the maze compared to the rats from the other two groups. The memory of these rats was clearly impaired by the fructose in their diet and lack of DHA; it seems that fructose could lessen the effects of DHA.
Another research study on sugar performed at Aarhus University in Denmark found that sugar intake can alter the reward-processing circuitry of the brain in a way similar to addictive drugs. After just 12 days of sugar intake, the dopamine and opioid systems in the brain change. The sugar craving becomes more like an addiction, making it hard to replace that late-night sugary snack with something nutritious. We are directed by our brains to seek pleasure and avoid pain, whether that be the pain of withdrawal or the aftertaste of collard greens. It can be difficult to resist sugar especially when it is all around you — from donut sales in Mason Hall to jungle juice at parties to chocolate chip cookies at Mosher-Jordan Residence Hall’s dining hall.
So where do we go from here? The first option is substitution. We all get that sweet tooth every once in a while, but how we choose to satisfy the sugar craving makes all the difference. Instead of grabbing candy, try a piece of fruit. This way you can still get your sugar fix, but without overdosing on added sugars. Another option is incorporating more DHA-rich foods into your diet. These include walnuts, salmon, edamame and kidney beans. A diet rich in DHA can counteract the sugar, increasing learning and memory by strengthening the synapses within the brain. For the risk-takers, another option is to challenge yourself to a sugar detox.
Sure, sugar overdosing probably does not fully account for failing an exam, but I do think there is enough evidence to convince me to put down the Sour Patch Kids and reach for a healthier alternative next time I’m struggling to keep my brain working through a practice exam late at night.
Emily Ulrich can be reached at emulrich@umich.edu.