Sugary drinks that also contain caffeine can supercharge memory and attention, according to a brain scanning study.
Together they make the brain more efficient, lowering the amount of processing it needs to perform the same task.
Brain scans showed that people given glucose and caffeine performed just as well on a task with less activation in their brains.
In other words, their brains did not have to work as hard to do the same task.
It is similar to the way a professional athlete can put in less effort to cover the same distance as a person of ordinary fitness.
Surprisingly, caffeine on its own had little effect.
Josep M. Serra Grabulosa, the study’s first author, explained:
“Our main finding is that the combination of the two substances improves cognitive performance in terms of sustained attention and working memory by increasing the efficiency of the areas of the brain responsible for these two functions.”
For the study 40 people were given either 75g of glucose, 75mg of caffeine, both, or a placebo.
They were given tests of memory and attention while their brains were scanned.
Only the combination of glucose (sugar) and caffeine caused the boost in performance.
The study was published in the journal Human Psychopharmacology: Clinical and Experimental (Serra Grabulosa et al., 2010).