Chewing gum is considered the world’s most common habit and over 374 trillion sticks of it are made every year. Many people use chewing gum not only for its flavor, but also to help them relax, concentrate, relieve nervous tensions, enhance memory and mental performance, lose weight and even to speed up recovery after gastrointestinal surgeries. Researchers at the Centre for Occupational and Health Psychology, Cardiff University, UK have taken a particular interest in the cognitive effects of chewing gum and in 2009 they published a study stating that gum increases alertness, accuracy and overall intellectual performance but has no effect on memory. However, according to a follow-up study conducted at the same University, and published in the Quarterly Journal of Experimental Psychology (2012), chewing gum may actually impair short-term memory and compromise performance on memory related tasks.
In order to assess the precise effects of chewing gum on memory, the researchers asked 40 students to chew gum vigorously and to simultaneously memorize a sequence of randomly combined words and letters in the order that they were heard or seen. A second group of students were asked to memorize the same word and letter sequences, but they were instructed to chew gum naturally. A third test was also performed, where the students were asked to identify the missing items in a sequence, while chewing gum. The study found that all three situations resulted in reduced performance on short-term memory related tasks. More specifically, the students experienced forgetfulness and consequently, a greater difficulty in recalling the correct order of the word sequences.
According to Gizmodo, Australia, researchers “suggest that the periodic action that is chewing gets in the way of repetitious cognitive tasks. If you try and memorize a phone number while tapping your finger, you’ll find it much harder than if you’re not tapping — and they suggest the exact same thing is true of chewing. In fact, they (the researchers at Cardiff University) even performed an experiment along those lines, and found that both tapping and chewing gum had similar (compromising) results on short-term memory.”
The results of the most recent Cardiff study, directly contrast three past studies. The first opposing study found that chewing gum results in better spatial recognition memory, as well as improved short-term number recognition and word recognition tasks (Wilkinson et al, 2002). The other two opposing studies (Baker et al., 2004, and Johnson & Miles) found that chewing gum enhances recall performance of a relatively long list of words. Some researchers hypothesize that gum enhances memory because the actual process of chewing gum increases blood flow to the brain. This hypothesis however, does not explain the results of the most recent Cardiff study which found that gum actually increases forgetfulness and compromises memory.
One explanation for the discrepancy in study results may be the flavor of the gum, or lack thereof, used in the studies. According to the Cardiff study authors “The discrepancy between the current study and previous research on the effects of chewing on short term memory could be associated with the absence of flavor in the gum used in the present study. Flavor has previously been suggested as one factor underpinning the beneficial effects of gum.” It looks like the verdict is still out when it comes to the effects of chewing gum on short-term memory, but if you do choose to chew during an important test, you may want to choose a long-lasting, flavorful variety!