Your Daily Coffee Just Might Jolt Your Memory
New study suggests caffeine not only wakes you up, but also may aid your recall
By Mary Brophy Marcus
SUNDAY, Jan. 12, 2014 (HealthDay News) -- Swarms of morning commuters clutch cups of coffee to kick-start the workday. But a new study suggests caffeine might do more for the brain than boost alertness -- it may help memory too.
Researchers from Johns Hopkins University looked at caffeine's impact on memory while excluding its other brain-enhancing factors. The study showed that caffeine enhances certain memories for up to 24 hours after it's consumed.
"The finding that caffeine has an effect on this process in humans -- the process of making memories more permanent, less forgettable -- was one of the big novelties," said study author Michael Yassa, an assistant professor of neurobiology and behavior at the University of California, Irvine, who conducted the research while at Johns Hopkins.
The study, which was funded by the U.S. National Institutes of Health and the U.S. National Science Foundation, included more than 100 participants who were "caffeine naive," meaning they were not big coffee, tea or cola drinkers, Yassa said.
"We picked people who were getting less than 500 milligrams of caffeine a week," he said. "Most weren't coffee drinkers. Most had a soda once or twice a week."
Coffee's caffeine content varies greatly. Most average-size cups contain about 160 milligrams (mg), Yassa said. But a 16-ounce cup of Starbucks coffee packs 330 mg of caffeine, according to the Center for Science in the Public Interest.
A dose of at least 200 mg of caffeine was needed to enhance memory consolidation, the researchers said.
For the study, which was published online Jan. 12 in the journal Nature Neuroscience, the researchers asked the participants to look at hundreds of common, everyday images on a computer screen: shoes, a chair, a rubber duck, etc.
"We asked them to tell us if it was an indoor or an outdoor object, but we didn't really care about what they said," Yassa said. "We just wanted them to attend to the object, to get that object into their brains."
Five minutes after the participants looked at the images, half were given 200 milligrams of caffeine and half received a placebo. They returned 24 hours later, after the caffeine was out of their system, and looked at more images of objects. They were asked to label the pictures as either old, new or similar to the original images they'd seen (for example, a picture of a duck they viewed the day before, but taken from a slightly different angle).