During the holidays last year, I attended two events in one day – a pancake breakfast with Santa in the morning, and a Lupus luncheon event in the early afternoon. I filled myself to the brim with holiday goodies at both events, and washed it all down with several cups of coffee. I always choose decaf, and did so at both places.
However, that afternoon, as I lay in bed trying to fall asleep, I felt the familiar jitter of yesteryear – that old caffeine high from college that isn’t so much a high as it is a convergence of sweaty palms and a frazzled brain. I HATE that feeling, and although I was able to fall asleep for a short period of time, when I awoke, I felt like my brain had been “on” the whole time. I wasn’t rested, and my eyes were still bugging and my hands were shaky. I'd clearly had a cup or two of regular coffee somewhere along the way. No doubt about it.
So what gives? Is the orange carafe no longer the universal sign for decaf? I was definitely hoodwinked that day…and I’ve been careful to ask before pouring since then. No need to repeat those wired feelings ever again!
As you can imagine, caffeine and I aren’t fast friends. I know many people who rely on the stuff to get them through the day (or even those first few moments of the morning), and to them, I say go for it. I’m glad they’re not quite as sensitive as I am (although surprisingly, when I drink a caffeinated soda every blue moon, I don’t suffer any consequences - weird, huh?)
But because I’m such a proponent of re-energizing the old fashioned way (via a nap), I couldn’t help but jump at the chance to share with you the findings of a study done at the University of California, featured in a past issue of Behavioural Brain Research. The results? Caffeine was found to impair motor learning and verbal memory, while an afternoon nap benefited all types of learning. A-ha! I knew it. Before I continue to gloat…here are the official details of the study:
Ninety percent of Americans use caffeine daily, some substituting it for sleep. While caffeine enhances alertness and concentration, it’s been unclear whether it also helps learning and memory. By contrast, daytime naps, like nighttime sleep, benefit both alertness and memory, according to this series of studies.
In this first head-to-head comparison, 61 participants trained in the morning on verbal memory, motor and perceptual learning tasks. After lunch, one group napped (60-90 minutes), while two other groups listened to a book on tape and received a pill containing either the caffeine equivalent of a little less than a Tall Starbucks coffee (200mg) or a placebo. Later in the afternoon, the three groups were tested to see how they had learned the tasks.
The nap group performed significantly better on a finger tapping motor task and in recalling words than the caffeine group. The nap group also trumped the other groups on a texture discrimination task of perceptual learning. The placebo group performed better than the caffeine group on all three tasks. Curiously, just thinking that the pill might contain caffeine – the placebo effect – helped as much as a nap on the motor task.
Evidence suggests that caffeine interferes with tasks that require processing explicit, as opposed to implicit information – like recalling a specific word, versus remembering how to type or ride a bike. Studies show that consolidation of such explicit verbal memory during sleep depends on lowered levels of the chemical messenger acetylcholine in the brain’s memory hub. Yet, by blocking activity of a natural sedative chemical, caffeine boosts acetylcholine in this hub.
“This increase in acetylcholine by caffeine may impair the consolidation process by blocking replay of new memories,” proposes Sara Mednick, Ph.D, who spearheaded the study. “Consistent with this, we found that the greater the explicit component of each task, the worse the caffeine group performed.”
Sleep well, little lupites. It's good for you!
*Article reprinted from the National Institute of Mental Health.