Coffee Improves Your Memory

By Jane Farrell

Drinking coffee doesn’t just provide an energy boost, it may also improve your memory. 

Michael Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins, and his team of scientists published their finding in the journal Nature Neuroscience. They found that caffeine improves memory for up to 24 hours after it’s consumed.

"We've always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans," said Yassa, senior author of the paper. "We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours."

In the study, participants who didn’t regularly consume caffeine were given either a placebo or a 200-milligram caffeine tablet. They were then tested five minutes after studying a series of images. To determine caffeine levels, the investigators took saliva samples both before the test and at one, three and 24 hours after the test.

The next day, both groups were tested on their ability to recognize images from the previous day. Some images were the same, others were new, and still others were similar to the previous images but were not the same.

More members of the caffeine group were able to correctly identify the new images as "similar" to previously viewed images.The brain's ability to recognize the difference between two similar but not identical items reflects a deeper level of memory retention, the researchers said.

The research is different from prior experiments because the subjects took the caffeine tablets only after they had viewed and attempted to memorize the images.

"Almost all prior studies administered caffeine before the study session, so if there is an enhancement, it's not clear if it's due to caffeine's effects on attention, vigilance, focus, or other factors," Yassa said. "By administering caffeine after the experiment, we rule out all of these effects and make sure that if there is an enhancement, it's due to memory and nothing else."

In the U.S., about 80 percent of adults have caffeine on a daiy basis. The average adult has an intake of 200 milligrams, the same as the tablet given the subjects.

"The next step for us is to figure out the brain mechanisms underlying this enhancement," Yassa said. "We can use brain-imaging techniques to address these questions. We also know that caffeine is associated with healthy longevity and may have some protective effects from cognitive decline like Alzheimer's disease. These are certainly important questions for the future."