Objectives: This study examined whether some of the age-associated decrements in basic cognitive resources (information-processing speed and working memory) result from anticholinergic medication use (as measured by serum anticholinergic activity [SAA]) and whether such decrements are lessened by caffeine.
Design: Cross-sectional observational study.
Setting: University medical center.
Participants: One hundred fifty-two normal-elderly community volunteers.
Measurements: Two tests each of information-processing speed and of working memory were administered, and blood samples were drawn before and after cognitive testing to determine serum levels of anticholinergic activity and of paraxanthine-a caffeine metabolite.
Results: Elevated SAA was associated with a significant but modest slowing in information-processing time but only in those individuals who had low levels of serum paraxanthine. SAA did not correlate with performance on tests of working memory.
Conclusions: These results suggest that anticholinergic medications are a relatively minor contributor to the decrements in basic processing resources commonly found in studies of normal aging.