The impact of caffeine use across the lifespan on cognitive performance in elderly women

Authors: PERRY III, CLINTON - Tufts University; THOMAS, AYANNA - Tufts University; TAYLOR, HOLLY - Tufts University; JACQUES, PAUL - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; KANAREK, ROBIN - Tufts University

Submitted to: Appetite
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2016
Publication Date: 7/22/2016
Citation: Perry III, C.S., Thomas, A.K., Taylor, H.A., Jacques, P.F., Kanarek, R.B. 2016. The impact of caffeine use across the lifespan on cognitive performance in elderly women. Appetite. doi: 10.1016/j.appet.2016.07.028.

Interpretive Summary: Habitual caffeine consumption is often associated with slowed age-related cognitive decline. However, whether habitual caffeine intake preferentially spares different cognitive processes, such as processing speed, has not been clearly demonstrated. Furthermore, whether a caffeine consumption pattern based on current or lifetime consumption more appropriately represents an older individual's habitual caffeine exposure remains unclear. In the present study, our primary goal was to determine the impact of long-term caffeine exposure on current cognitive performance of elderly female participants. We hypothesized that higher levels of habitual caffeine intake would be associated with better performance on a variety of test batteries measuring different cognitive processes. We collected information from women, aged 56-83, about their current caffeine consumption patterns and history of use, including the age at which they began consuming caffeine. We used statistical models to examine the relationship between caffeine consumption and performance on test batteries designed to assess different cognitive processes, including processing speed, memory, inhibitory function (the process of tuning out information or stimuli that are not pertinent to the cognitive task at hand,) and executive function (which involves cognitive processes related to reasoning, planning and problem solving.) While we found no direct associations between caffeine exposure and overall cognitive performance, we found that caffeine consumption and participant body mass index, a marker of obesity, interacted such that a protective caffeine effect was observed for inhibitory function and speed of processing performance among obese women. However, a negative effect was seen among lean women. The differences by weight status may reflect differences in relative caffeine dose based on body size (i.e. the same amount of caffeine would result in an apparently larger relative dose for lean women compared to obese women.) These findings suggest that moderate amounts of caffeine may provide focal defense against the deleterious impact of social and dietary stress on cognitive performance in older obese individuals.

Technical Abstract: Habitual caffeine consumption has often been associated with decreasing age-related cognitive decline. However, whether habitual caffeine use preferentially spares different cognitive processes is unclear. Furthermore, whether basing habitual caffeine consumption patterns on current consumption or on a lifetime measure better represents an individuals use remains unclear. In the present study, we collected information from women, aged 56-83, about their current caffeine consumption patterns and history of use, including age they began consuming caffeine. Regression models assessed the relationship between caffeine consumption and performance on batteries designed to probe speed of processing, inhibition, memory, and executive function. While we found no direct associations between caffeine exposure and cognitive performance, we found that caffeine consumption and participant BMI interacted for inhibitory function and speed of processing performance. We discuss possible protective effects of long term caffeine use as well as the possibility of dose dependent effects.