Drinking a cup of coffee is not only a nice break for many, it also appears to be a memory boost as well, especially for older adults.

Researchers in the psychology department at the University of Arizona recently tested a group of over-65 adults to see if their memory function could be enhanced by caffeine. The results will be published in the January 2002 issue of Psychological Science by the American Psychological Society.

Memory in most older adults often depends on the time of day, says Lee Ryan, UA assistant professor of psychology and lead author of the study. Memory is "optimal early in the morning and (declines) during the late afternoon hours," Ryan said. Her study tested whether a simple stimulant - caffeine, in this case - would have an effect on this decline.

The 40 participants, all over age 65, and active and independent, were tested at 8 a.m. and again at 4 p.m. on scheduled days. The test used was the California Verbal Learning Test. Subjects were given coffee during both the morning and afternoon test segments.

One group received 12-ounce cups of regular coffee containing approximately 220 to 270 mg of caffeine. A control group drank decaffeinated coffee, which usually has no more than 5-10 mg of caffeine per serving. Ryan said participants could not tell whether they were drinking regular or decaf.

Ryan and her co-researchers, Colleen Hatfield and Melissa Hofstetter, both UA undergraduates during this research project, found that participants who ingested decaffeinated coffee "showed a significant decline in memory performance from morning to afternoon." The group who ingested the caffeine showed no decline in performance on the memory tests.

"The results suggest that time-of-day effects may be mediated by nonspecific changes in the level of arousal," the authors report.

Ryan says the test isn't an across-the-board endorsement of caffeine or coffee, since other stimulants would likely have worked just as well. Test subjects also were already coffee drinkers, and used to the effects of caffeine, whereas non-coffee drinkers might have experienced negative side effects (shakiness, anxiety, decreased concentration).

But she does say that "administration of a simple stimulant, caffeine, in a dose that most adults readily consume daily, ameliorates memory impairment arising from time-of-day effects in older adults.

"The fact that these effects are easily reduced is probably good news for older adults, and vindication for those of us who live with a coffeepot always at the ready."

Ryan, who is also director of the UA Cognition and Neuroimaging Laboratory, which uses magnetic resonance imaging (MRI) to study brain function, said future research will use MRI to study the effect of caffeine on brain function and blood flow.

---University of Arizona

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