Want a brain boost? Grab a stick of gum and get chewing, new research suggests. Though you may want to ditch that wad before trying any mental gymnastics, as gum only helps improve test scores if chewed before, not during, testing.


The chewing motion gets blood flowing to the head, the researchers suggest, where it improves memory, according to how quickly a test-taker can recall information in the lab. The effect only lasted a few minutes, but researchers think chewing gum before a test could give students an advantage in some ways.


"I do not know how things would work when you're testing something learned days or weeks ago, but given the study's findings, I can speculate that if both working memory, episodic memory and general speed of information-processing benefit from gum-chewing, so would many testing situations, which presumably rely extensively on those mental capacities," study researcher Serge Onyper, of St. Lawrence University, in Canton, N.Y., told LiveScience.


Gum in the lab

The researchers tested 224 undergraduates from St. Lawrence University, dividing them into three groups. One chewed gum before and during the test, another chewed gum for five minutes before being tested and a third didn't chew anything. The researchers then gave them a battery of tests to determine their brainpower.


They found that a burst of gum-chewing before testing improved a student's performance on several of the tests, but only for a short period. The effect was strongest right after gum-chewing, and dropped to normal levels within 20 minutes. The gum-chewing helped during recall and memory tasks especially.


"Within the 15-to-20-minute 'window' of the effect, the chewing-gum group recalled 25-to-50-percent more items than the controls, which is statistically significant, but in practical terms amounts to a difference of two-to-three words," Onyper said.


Your brain on gum

The researchers think that this improvement in brainpower is because the chewing warms up the brain, a phenomenon they call by the suggestive name "mastication-induced arousal." This arousal turns the brain on just before test taking, and gets more blood (and therefore energy-giving sugar) flowing to the head.


Chewing gum is known to increase heart rate and blood pressure, sending more blood to the brain for a total of about 15 to 20 minutes. Mild exercise probably has the same effect, as it also gets your heart rate up, Onyper said.


The test takers who chewed gum the entire time didn't show this improvement. The researchers think the extra brainpower it takes to actually chew the gum takes away from the brain's ability to take the tests, so the benefits of pre-chewing don't show up in test scores. This could explain why results of previous studies have seemed contradictory: Some tested participants while they were chewing continually.


Because the participants were specifically asked to chew the gum, it's possible they were thinking about it a little more than they would be normally, Onyper said. "In real-world situations the chewing might be more unconscious, automated, in which case it would take up very little cognitive resources and probably not affect performance much."


The study was published in the October/November 2011 issue of the journal Appetite.


You can follow LiveScience staff writer Jennifer Welsh on Twitter @microbelover. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.



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