Bazian, which conducts reviews for the National Health Service (NHS) in the UK, said that the study, which garnered national media attention, was only based on a small sample size and had no effect on people’s health.
The study by Hirano et al. was made available online last week ahead of publication in peer-reviewed journal Brain and Cognition.
The paper concluded that chewing induced an increase in arousal levels in in some parts of the brain and improved alertness, which could lead to improved cognitive functioning.
Its conclusions were based on behavioural tests involving 17 adults chewing gum.
Bazian said in an article on NHS Choices: “Both the Daily Mail and the Daily Express covered the story, with the Mail reporting that, "Chomping on gum is good for the brain and can boost alertness by 10%."
“However, this claim is based on what is actually a very small study involving just 17 healthy young adults. Such a small sample size means that the results of the study need to be viewed with caution.”
“…The study may be of interest to some researchers, but at the moment it does not have any obvious practical implications for people's health or day-to-day lives.”
Under the experiment, study participants' brains were analysed using functional MRI scans while they conducted a cognitive task with and without chewing gum.
Participants were told to look at a computer screen that flashed up images of arrows and had to select the correct direction.
The MRI scans monitored blood flow in the brain, with higher blood flow indicating increased activity in specific regions of the brain. Researchers also assessed reaction times and accuracy with and without gum.
They found that chewing helped some areas of the brain become more active, such as the anterior cingulate cortex, which aids decision-making.
A previous study by Kozlov et al. in the Quarterly Journal of Experimental Psychology found that chewing gum could in fact impair short-term memory. See HERE.
Brain and Cognition
‘Effects of chewing on cognitive processing speed’
Authors: Yoshiyuki Hiranoa , Takayuki Obata , Hidehiko Takahashi, , Atsumichi Tachibana, , Daigo Kuroiwa, Toru Takahashi , Hiroo Ikehira, Minoru Onozuka