Abstract

Background: Caffeine is widely consumed by medical students to combat fatigue and enhance academic performance. However, its effect on cognitive functions such as memory remains unclear.

Objective: To evaluate the association between caffeine consumption and short-term memory performance in medical students.

Methods: A cross-sectional study was conducted among 100 undergraduate medical students using a structured questionnaire and a digit span memory test. Participants were categorized based on their daily caffeine intake into low (<100 mg), moderate (100–300 mg), and high (>300 mg) groups. Mean digit span scores were compared using ANOVA.

Results: The average digit span scores were 5.1 ± 0.9 (low), 5.8 ± 1.1 (moderate), and 5.4 ± 1.0 (high) across the groups. The moderate intake group showed a statistically significant improvement in memory scores compared to the low intake group (p = 0.03).

Conclusion: Moderate caffeine intake may enhance short-term memory in medical students, but higher consumption does not offer additional benefits. Further studies with larger samples and longitudinal designs are needed.

Introduction

Caffeine, a natural stimulant commonly found in coffee, tea, and energy drinks, is a popular aid among students, especially in demanding academic settings such as medical schools. While it is known to increase alertness, its impact on cognitive functions, particularly memory, is less clearly defined.

Medical students often rely on caffeine to maintain attention during long study hours, yet few have considered whether their consumption habits translate into better cognitive performance. This study aims to assess the relationship between different levels of caffeine intake and short-term memory performance among medical students.

Methods

Study Design and Participants

This cross-sectional study was conducted in March 2025 at [Name of Medical College]. A total of 100 undergraduate medical students aged 18–25 years were recruited using convenience sampling.

Data Collection

Participants completed a self-administered questionnaire documenting demographic data, average daily caffeine intake (estimated from beverage frequency), and sleep patterns. Based on reported caffeine consumption, students were grouped as:

• Low: <100 mg/day

• Moderate: 100–300 mg/day

• High: >300 mg/day
  
  

Short-term memory was assessed using the forward digit span test from the Wechsler Adult Intelligence Scale. The maximum number of digits correctly recalled in sequence was recorded.

Statistical Analysis

Data were analyzed using SPSS version 26. Mean digit span scores across groups were compared using one-way ANOVA. A p-value of <0.05 was considered statistically significant.

Results

Out of 100 students, 60% were male and 40% female. The mean age was 21.2 ± 1.5 years. The distribution of students by caffeine intake was: low (n=30), moderate (n=45), high (n=25).

The average digit span scores were:

• Low intake: 5.1 ± 0.9
  
  

• Moderate intake: 5.8 ± 1.1
  
  

• High intake: 5.4 ± 1.0
  
  

The ANOVA test showed a significant difference between groups (p = 0.04). Post-hoc analysis revealed that students in the moderate caffeine group had significantly higher scores compared to the low intake group (p = 0.03). No significant difference was found between moderate and high intake groups.

Discussion

This study suggests that moderate caffeine consumption may enhance short-term memory in medical students. The observed improvement may be due to caffeine’s stimulant effect on the central nervous system, leading to increased alertness and attention.

However, high caffeine intake did not further improve memory performance and may even impair it due to side effects like anxiety or poor sleep, which negatively affect cognition.

Limitations of this study include the cross-sectional design, self-reported caffeine intake, and lack of control for other variables such as stress levels or nutritional status. Future studies should employ experimental designs and include objective cognitive assessments.

Conclusion

Moderate caffeine intake appears to be associated with improved short-term memory performance in medical students, whereas excessive intake offers no additional cognitive benefits. Medical students should be mindful of their caffeine consumption to optimize academic performance.

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