Chewing gum sales exceed 4 billion dollars in the U.S. alone. People chew gum for many reasons. For instance, chewing gum is assumed to stimulate the production of saliva and freshen breath, clean teeth, help digestion, relieve tension, and improve mood. In an article published in the March/April 2019 issue of Applied Cognitive Psychology, Ginns and colleagues argue that chewing gum may also enhance attention, alertness, and learning.1
Benefits of chewing gum
Though some research has concluded that chewing gum improves memory, concentration, sustained attention, and reduces stress, other research has found no such benefits. A recent systematic review of 21 studies found not a strong, but a statistically significant relation between chewing and sustained attention.2
An important question is how can chewing gum improve attention, memory, or learning?
One set of theories suggest chewing gum increases physiological arousal. Optimal physiological arousal then results in improved attention, learning, memory, and performance. Alternatively, chewing gum might reduce “stress hormones” (e.g., cortisol), resulting in reduced stress and thus improved mental functions and performance. Lastly, the performance-related benefits of chewing gum may result from increased blood flow and the availability of glucose (i.e., sugar) in the brain.1
Two experiments on chewing gum
In a series of two experiments, Ginns et al. tested the following two hypotheses: First, compared to students who did not chew gum, students who chewed gum while studying would be more alert. Second, chewers would outperform non-chewers regardless of material studied or method of instruction.
Experiment 1: Chewing gum while studying for a physiology lesson
Forty college students (13 males) were randomly assigned to non-chewing and chewing conditions. Both groups were asked to study a physiology lesson (on the heart’s functions).
Before studying the lesson, students in the chewing condition were provided a piece of peppermint gum and asked to chew gum while studying. After studying, both groups completed the same two multiple-choice tests on heart physiology.
Analysis of the data showed the two groups were comparable, but unexpectedly those assigned to the chewing condition appeared to have been more alert than the non-chewing group already (prior to chewing gum). After controlling for this difference, data showed that chewing gum did not appear to raise alertness to a statistically significant level in the chewing condition.
However, on combined multiple-choice tests, the difference between chewing and non-chewing was statistically significant, suggesting that chewing gum helped improve learning.
Therefore, the results supported the second but not the first hypothesis.
Experiment 2: Chewing gum while studying for a math lesson
The second experiment utilized a different subject of study (mental multiplication) and method of instruction (using worked examples and practice questions), but otherwise, it used a similar design and procedure as the previous investigation.
Forty students (10 males) were randomly assigned to chewing and non-chewing groups. As before, only one group chewed gum while studying the lesson. Both groups then completed two 10-item tests.
Both groups were equivalent on pretest measures, including alertness.
Supporting the authors’ first hypothesis, data analysis showed gum chewers, compared to non-chewers, were more alert at the end of the study period. Furthermore, in the test phase, chewers, compared to non-chewers, made fewer errors and answered a greater number of test questions correctly.
The magnitude of the positive effects of chewing on test performance was comparable in both experiments, despite the lesson on mental mathematics (and thus the gum chewing phase) being much shorter than the lesson on heart physiology (9 vs. 20 minutes).
Concluding thoughts on chewing gum and learning
These findings suggest that chewing gum while studying might improve test performance. The study’s use of realistic lessons and two very different types of material and instructional design supports real-life application and generalizability of the findings. Of course, future studies need to examine the effects of the number and type of gum chewed, time of day, duration of lessons, the period between chewing gum and being tested, participants’ age range, and type of learning (e.g., classroom learning as opposed to self-study).
The takeaway is that chewing gum while studying might be helpful in improving test performance, perhaps through effects of chewing gum on alertness. But we need to keep in mind that such benefits need to be balanced against negative aspects of chewing gum, like jaw pain or tooth cavities. In addition, alternative methods of increasing alertness should be considered. I do not mean drinking a lot of tea or coffee—or worse, so-called energy drinks—which also have side effects, but approaches like exercising, getting a good night's sleep, and managing stress, which might be safer and healthier ways of increasing alertness.
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Ginns, P., Kim, T., & Zervos, E (2019). Chewing gum while studying: Effects on alertness and test performance. Applied Cognitive Psychology, 33, 214-224.
Miquel, S., Haddou, M. B., & Day, J. E. L. (2019). A systematic review and meta-analysis of the effects of mastication on sustained attention. Physiology & Behavior, 202, 101-115.