The study in the Journal of Prosthodontic Research by Tasaka et al. from the Tokyo Dental College found that cortisol levels, a measure of stress, fell after prolonged gum chewing.
“The present results indicate that chewing time affects the reaction of the endocrine system to mental stress, and that continuous chewing for more than 10 min is effective in reducing stress,” concluded the researchers.
Method & findings
14 healthy men were asked to perform arithmetic calculations for 30 minutes to build up stress followed by chewing gum for 5, 10, 15 minutes or not at all. Each participant was assigned all chewing conditions, each on different days.
The researchers collected salvia samples from participants before and after the stress-loading mental arithmetic tasks and also measured cortisol levels.
Each experiment was completed at 25 minutes after stress loading – so for example under the non-chewing condition there was a 25 minute rest period after stress loading and for the 15-minute chewing condition there was 10-minutes of rest before samples were taken.
The researchers saw no differences in salivary alpha-amylase activity among the gum chewing conditions, but noted a significant decrease in cortisol levels at 15 minutes of chewing compared to 5 minutes.
Blood collections may be inaccurate
“…There may be a relation between number of chewing strokes and stress reduction, which would also apply during daily consumption of foods,” they said.
The researchers used a tasteless gum provided by South Korean confectioner Lotte.
Tasaka et al. suggested that many previous studies may be less accurate because they used blood collection rather than salivary markers to measure stress, which could cause further stress.
Non-dental gum benefits
The research builds on earlier studies linking chewing gum to reduced stress. Three recent Wrigley funded studies found that chewing gum improved measures of stress and lead to a more positive mood.“Such an effect would not totally remove stress at work but would lead to a meaningful reduction in the problem,” said one of the studies published in the journal Appetite.
Another recent study in the journal Appetite by Erbay et al. claimed that chewing gum could reduce symptoms that occur when people are depressed such as loss of appetite and flatulence.
Daytime tiredness may also be alleviated by gum chewing, according to another study in the journal Physiology and Behaviour.
But UK health group Bazian previously issued a caution to consumers about a Japanese study last year that linked chewing gum to improved brain performance because the sample size – 17 people – was too small.
Gum chewing drawbacks
Other research has reported negative effects from chewing gum.
A study published in the journal Pediatric Neurology associated excessive gum-chewing with chronic headaches in children and adolescents.
Other research in the journal Eating Behaviors said that contrary to popular belief chewing gum was not an appetite suppressant and mint-flavored varieties may even deter people from healthy foods like fruit. However, A Wrigley-backed study had previously said that gum could reduce cravings for sweet and salty snacks. See HERE.
Kozlov et al. said in the Quarterly Journal of Experimental Psychology in 2012 that chewing gum could impair short-term memory. See HERE.
Journal of Prosthodontic Research, Vol 58, Issue 1, p 48–54
‘Influence of chewing time on salivary stress markers’
Authors: Akinori Tasaka et al.