Effects of Caffeine Consumption on Physiological Markers of Stress

Abstract

Caffeine is known to be used by college students to help stay awake, focus and increase academic performance. Caffeine’s biological mechanisms are fairly well-understood, but its effect on a stress response should be better explored. The purpose of this study is to examine the effect of caffeine on key physiological indicators of stressblood pressure (BP), heart rate (HR), and electrodermal activity (EDA)- in healthy college students. Forty-five students participated in this experiment, which began with baseline measurements of the three variables mentioned, followed by a stressor in the form of a brief math test, and a retesting of those three variables. The participants also completed a brief questionnaire to determine their caffeine usage, and were sorted into different groups based on their caffeine consumption. Statistically significant interactions could not be shown for most of the variables; however, there was a significant difference in the change of systolic blood pressure in participants when divided based on their intake of caffeine on the day of the experiment. Participants who consumed very high levels of caffeine (286mg and above) on the day of the experiment had a greater increase in systolic blood pressure than those who had less caffeine. High caffeine consumption is therefore correlated with a larger increase in systolic blood pressure in response to stress.