Eating high-GI breakfast cereals may improve your memory, a new study suggests.
But the effects of such cereals are short term, say sceptics, and care is needed in using glucose to boost brainpower.
GI or glycaemic index is a measure of how rapidly carbohydrates break down into glucose. High-GI foods break down into glucose rapidly.
PhD student Michael Smith of the University of Western Australia compared the impact of low-GI and high-GI cereals on the ability of healthy adolescents to remember a list of words.
"Those who had consumed the high-GI cereals actually recalled significantly more words than those who consumed the low-GI breakfast cereal," says Smith.
The research, which has been submitted for publication, will be presented at the IBRO World Congress of Neuroscience in Melbourne later this month.
In the study, 37 school students, aged 14-17 years, ate a popular corn-based cereal (high-GI) or a high fibre bran-based cereal (low-GI).
The students were then tested to see how well they could memorise a list of 20 names of tools, fruits, vegetables, herbs, spices and kitchen utensils.
Smith says the ones that ate the high-GI cereal remembered on average 1.52 more words than the ones that ate the low-GI cereal.
While the difference is small, he says it's statistically significant.
Against the grain
The findings support previous research by Smith's PhD supervisor, neuropsychologist Dr Jonathan Foster, and others, that sugary drinks can boost your ability to remember what you're told.
Smith says this is the first time cereals have been shown to have this so-called "glucose memory facilitation effect".
But the findings go against previous research showing low-GI cereals are best for the memory, he says.
Smith thinks the reason he's found the opposite lies in the memory performance test he used.
Unlike previous cereal studies, the participants in his study were distracted, by having to make a series of hand movements, while they were trying to memorise words.
Smith says this "divided attention" test, also used in the earlier sugary drink studies, better reflects what happens in the real world, especially for adolescents in a busy classroom.
"Very rarely will the students have 100% attention focused on the teacher," he says. "There's generally something going on that they'll have to block out in some way."
Responses
Research psychologist Dr Janet Bryan, of the University of South Australia in Adelaide, says the short-term memory-boosting effect of sugary drinks is a well-replicated finding.
But she says its practical use needs to be limited.
"It could be useful," she says. "[But] I wouldn't advocate sugary drinks in the classroom."
And the same applies for a glucose rush from a high-GI cereal, says Bryan.
She suggests it would be better to investigate which cereals give a sustained improvement in memory.
Then there's the question of whether the low-GI cereal used by Smith is comparable to the low-GI cereals used in previous studies.
"This sounds like an interesting study with a good design," says GI-guru and nutritionist Professor Jennie Brand-Miller of the University of Sydney.
"But I'd like to verify that the low-GI breakfast cereal was really truly low GI," says Brand-Miller, commenting on an outline of the study.
Study funding?
While studies showing benefits from sugary drinks and cereals are a likely boon to soft-drink and breakfast cereal manufacturers, Smith did not rely on industry funding for his study.
Smith's supervisor Foster has had some industry funding in the past, although says most of his initial published work on the glucose memory enhancement effect was university funded.
http://www.abc.net.au/science/news/stories/2007/1965818.htm
Sugary breakfast cereals may boost memory
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Monday, 2 July 2007
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High-GI breakfast cereals seem to boost short-term memory, especially if you're distracted. But what are its long-term effects? (Image: iStockphoto)
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