Working independently, both caffeine and sugar provide benefits to attention and memory. However, there is sparse literature on the synergistic effects on improved cognitive performance between caffeine and sugar when taken together. This study explored the dynamics between caffeine and sugar when consumed under ordinary conditions – as a cup of coffee. Twenty-four undergraduate students (15 women and 9 men) were asked to complete a baseline cognitive test, and one of the three variables was given at random in the form of a cup of coffee: decaffeinated with sugar, caffeinated with no sugar, and caffeinated with sugar. The remaining two variables were administered at random over the next two sessions. Results were compared within subjects and between subjects to assess effects on short-term memory and cognitive performance. We hypothesized that there would be a significant improvement on short-term memory as measured by correct responses on n-back tests when caffeine and sugar were consumed simultaneously, as opposed to consuming the caffeine or sugar independently. Additionally, we anticipated that participants’ caffeine consumption habits would influence the effects of different treatments on cognitive performance. The results did not show a synergistic effect on cognitive performance by caffeine and sugar when taken together, although there was a trend supporting this hypothesis in non-regular coffee drinkers as opposed to habitual coffee drinkers. Additionally, there was evidence supporting our hypothesis that caffeine habits influence the cognitive benefits of caffeine and sugar consumption. Non-coffee drinkers saw a higher increase in cognitive performance after consuming caffeinated beverages with sugar, while coffee drinkers received greater benefits from drinking caffeinated beverages without sugar.
Urquiza, Sandra P. and Vieyra, Michelle
"Assessing the Synergistic Effect of Caffeine and Sugar on Cognitive Performance in Undergraduate Students,"
Journal of the South Carolina Academy of Science: Vol. 13
, Article 6.
Available at: https://scholarcommons.sc.edu/jscas/vol13/iss2/6