An increasing number of scientific studies suggest that chewing gum may improve concentration and mental alertness during tasks requiring sustained attention, though the evidence remains mixed depending on the nature and duration of the task.

One prominent study in this field, conducted by researcher Kate Morgan in collaboration with the British Psychological Society, involved 38 participants split into two groups who performed a 30-minute listening task requiring identification of an odd-even-odd number sequence within a random series.

Results showed that participants who chewed gum had faster reaction times and more accurate responses, especially in the later stages of the task when concentration typically wanes among non-chewers.

In another study conducted on four classes of third-grade students (aged 8-9 years) at a German school, researchers found that chewing gum during a 16-minute concentration test had a statistically significant positive effect on student performance compared to non-chewing peers.

How do scientists explain this effect?

Researchers propose several mechanisms behind these findings: one theory suggests chewing gum increases glucose availability in the brain due to heightened metabolic activity from mastication, while another relies on the "optimal arousal hypothesis," positing that cognitive benefits stem from elevated alertness and general attention during chewing.

Studies have documented that chewing increases heart rate, blood pressure, cortisol levels, and cerebral blood flow—physiological changes commonly associated with improved cognitive function.

A systematic review published on PubMed also showed that chewing activates the ascending reticular activating system responsible for regulating alertness in the brain, speeding up mental processing, while functional MRI (fMRI) studies observed increased activity in the anterior cingulate cortex and left prefrontal gyrus during chewing—areas linked to executive function and attention.

Behind the Scenes: The Deeper Physiological Explanation

Several researchers have delved into the minute physiological changes accompanying chewing. Studies by Varela and colleagues, Wilkinson and colleagues, and Hasegawa and colleagues have documented increased heart rate and blood pressure during chewing, while a study by Smith observed a simultaneous rise in cortisol levels.

Research by Hasegawa, Onozuka, and Sesay over various years examined chewing's effect on cerebral blood flow, indicating increased brain perfusion during chewing, which may support cognitive performance by enhancing oxygen and glucose delivery to the brain.

At the neural level, studies using electroencephalography (EEG) and functional MRI (fMRI), including research by Hirano, Morinushi, Takada, and Miyamoto, have shown signs of increased cortical excitability and activity in brain regions associated with attention and executive functions during chewing, supporting the hypothesis that chewing may enhance neurological alertness—though the precise mechanisms remain under investigation.

Does the Type of Gum Make a Difference?

A study published by researcher Omar Latiouch and colleagues suggests that gum flavor may play an additional role. The study compared three groups: one chewing peppermint-flavored gum, one chewing flavorless gum, and one not chewing anything. After one month of follow-up, the peppermint group scored significantly higher, followed by the flavorless gum group, which in turn outperformed the control group. Researchers suggest that the scent and taste of peppermint may provide additional sensory stimulation that complements the mechanical effect of chewing itself.

A Curious Detail: Which Side Do You Chew On?

In a more specialized study published in neuroscience research, researchers found that the concentration effect from chewing may vary even by which side of the mouth is used in some individuals.

People with natural asymmetry in chewing muscle activity between sides, accompanied by a slight difference in pupil size—an indicator of imbalance in the nervous system responsible for alertness—showed greater improvement in mental performance when chewing specifically on the less active side, as if chewing from that side "rebalances" the brain's alertness system. This finding opens the door to a more precise understanding of individual variation in response to the same technique.

Impact in Work and Study Environments

The potential benefit extends beyond the lab: a series of studies (comprising four independent experiments) concluded that chewing gum during the workday was associated with higher productivity and fewer self-reported cognitive problems, along with a slight increase in morning cortisol levels but no significant effect on heart rate.

One experiment in the series noted that chewing rate and force did not greatly alter mood but had a limited effect on attention level. Notably, one experiment's results showed a curious contradiction: a slight increase in response time alongside a decrease in errors over the sustained attention task, reflecting the complexity of the relationship between chewing and continuous attention.

Is the Evidence Conclusive?

Most current evidence supports the idea that chewing gum can provide a temporary boost to alertness and concentration, especially during long or monotonous tasks like long-distance driving or extended study sessions. However, the effect size remains modest and varies across studies, and it is not considered a substitute for the basics of good concentration, such as adequate sleep and regular mental rest.