Caffeine and Memory

Anyone who has spent time at the Yellin Center may notice that we like our coffee. But we know that some research has raised issues about the impact of caffeine on learning and development, specifically noting in a blog we wrote last fall that Swiss researchers found that caffeine can slow brain development in rats. Caffeine consumption in young people is significant -- a recent study in Pediatrics notes that approximately 73 percent of children ages 2-11 consumed caffeine in a given day-- and rates of consumption are remaining steady, even as children drink less soda, because highly caffeinated energy drinks are accounting for a higher proportion of caffeine intake.

We were therefore pleased to find some good news about caffeine in a recent study appearing in the journal Nature Neuroscience. It had long been known that ingesting caffeine before learning tasks improved subjects' memory for the material learned. In the new studies, the order of was changed; first, test subjects learned new material and only after that did they consume caffeine. The researchers found that this post-learning intake of caffeine had a positive impact on memory as much as 24 hours after caffeine ingestion. There was a correlation between the amount of caffeine ingested, with the maximal impact leveling off after 200 mg. (roughly the amount in one to two cups of medium strength coffee). Of note, this research was done on people, not rats.

So what is the "take away" from this study? Parents still need to keep a careful eye on the caffeine consumption of their children, but perhaps adding coffee to the mix for older students during exam week might not be such a bad idea.

Photo Credit: Toshiyuki IMAI/flickr

Study Indicates that Caffeine Slows Brain Development

The Swiss National Science Foundation has recently released the results of a study that indicates that caffeine may be more harmful to young people than most of us suspected. The research team has uncovered evidence that a moderate amount of daily caffeine consumption slowed brain development in pubescent rats.

There’s a reason the stereotype of teenagers sleeping until (at least) noon on weekends has gained traction: the teenage brain requires lots and lots of deep sleep for development. While their bodies are at rest, adolescents’ brains are hard at work, forming more connections between brain cells (synapses) than they ever have, or ever will again, in their lives. All this restructuring requires lots of high-quality rest, and researchers found that rats who consumed the caffeine equivalent of three or four rodent-sized cups of coffee weren't getting it. Their deep sleep time was reduced, and their brains matured more slowly compared to rats given only water to drink. Caffeinated rats displayed different behavior, too. The control group became more curious and investigative as they matured – par for the course for a young rat. But the group that had consumed caffeine was more timid and cautious.

Brian Legate

Especially troubling is the scientists’ observation that differences between the two groups persisted for many days after the administration of caffeine ended. Rats who had consumed caffeine continued to sleep for less time and less deeply even days after they’d been drinking only water, and were also less curious about their environments. This study comes at a time when young people are consuming caffeine at a higher rate than ever; according to the researchers, young people’s consumption has gone up 70% in the past 30 years.

More research is needed, of course, but because there are quite a few parallels between the development of rat brains and human brains, the study raises some legitimate concerns. Just to be on the safe side, parents may wish to steer their children toward decaffeinated sodas (or, better yet, water or real fruit juice) and herbal or green teas, which tend to have less caffeine than black. For teenagers already hooked on coffee, try decaf or a “half-caf” instead. And remember that caffeine can be hidden in unexpected places, like chocolate, so a scoop of vanilla ice cream or sorbet, or a piece of fruit might be a better nighttime treat than a mug of hot chocolate or a chocolate chip cookie.