We all remember that moment in class when the teacher caught us chewing a gum and thereby caught us breaking one of the number one classroom rules: No chewing gum in school!
But in society there is one more rumour which is well established in the minds of people for years: Chewing a gum is good for your concentration. So is chewing gum a neglected way of cognitive enhancement, or just a bad habit?

In the last years this topic has gained more and more interest in research. Many studies investigated the impact of chewing a gum on cognitive functions. All of them made use of cognitive batteries and let participants chew gum before or during they were going through tests which included tasks for memory or attention.

Several results of those studies sound very impressive. For example a piece of sugar-free gum can improve the immediate and the delayed recall of words as well as the working memory. Moreover chewing gum brings benefits in verbal working memory tasks, free recall, attention and the decline of reaction times. At least in some studies. Other authors see problems in those advantages of chewing a gum while performing in cognitive tests. They failed to find any effects of chewing gum on people’s memory, attention or on tasks like mental rotation. Sometimes these effects were even working in the opposite direction. A reason for these results could be the fact that cognitive and masticatory processes share some resources. So chewing a gum during a test situation could be hindering for the participants.

The mechanism behind the effect of chewing gum on cognitive performances is not really known. There are many theories regarding this like an increased availability of glucose in the brain and associated with it, an increased metabolic activity. Furthermore the elevation of the heart rate, the blood pressure, the cortisol level and the cerebral blood flow were also examined, which could cause an increased arousal.

It should also be considered that not every chewing gum is the same. Different flavours like mint or fruit, tasteless or caffeinated versions showed different effects, although the amount of these ingredients in the chewing gums alone could not explain these effects. Other interesting starting points for studies are, besides the flavour, the consistency of different chewing gums, the effort you need to chew it, your experience with chewing gum and the time when you chew it. Chewing gum right before you are performing in a cognitive task, but not during this performance, improves your results much more.

I think that every harmless method of cognitive enhancement like chewing gum, good food, sports or mediation should be a method of great interest for us and further investigations. It’s not always necessary to use enhancing drugs or invasive brain stimulation. Let’s support these natural ways of cognitive enhancement.

So the whole time while writing the blog I was chewing my gum. Now you can make up your mind if it was actually helpful to increase my brain activity or if it is a bad habit after all.