Energy Drinks
Impact on Vital Signs & Cognitive Performance
Pre-post Experimental Study • 47 Adults • Suez University & Suez University Hospital • 2026
Abstract
Research Abstract
Energy drink consumption has markedly increased among university students seeking improved alertness and enhanced academic performance. This pre-post experimental study aimed to assess the acute effects of energy drink consumption on vital signs and cognitive performance among 47 healthy adults at Suez University and Suez University Hospital. Physiological parameters were measured before and 30 minutes after consumption. Five cognitive domains were assessed using validated instruments. Results revealed statistically significant increases in all vital signs (p < 0.001) and improvements across all cognitive domains. These findings indicate that energy drinks produce short-term physiological stimulation alongside limited cognitive enhancement, warranting public health awareness regarding excessive use.
Aim
Assess acute effects of energy drink consumption on vital signs and cognitive performance among healthy adults.
Methods
Pre-post experimental. 47 participants. 5 vital signs + 5 cognitive tests, before and 30 min post-consumption.
Results
All vital signs significantly elevated. Cognitive improvements in mindfulness, working memory & processing speed (p < 0.001).
Conclusion
Energy drinks produce short-term physiological stimulation with limited cognitive enhancement. Excessive use warrants awareness.
Results
Statistically significant changes across all measures (p < 0.001)
Systolic BP
mmHg
Diastolic BP
mmHg
Heart Rate
bpm
Respiratory Rate
/min
Temperature
°C
📊 Vital Signs: Pre vs Post
🧠 Cognitive Performance
📅 Consumption Frequency
⚠️ Side Effects
✨ Key Findings
All vital signs showed statistically significant increases after energy drink consumption (p < 0.001)
Heart rate increased by an average of 3 bpm post-consumption
Systolic blood pressure rose by ~3 mmHg after consumption
Cognitive improvements were observed across all 5 domains tested
Working memory improved significantly (9.32 → 11.45)
Vital Signs Simulator
Drag the slider and explore how energy drinks affect your body
Number of Cans
Caffeine: ~0 mg
Safe limit: 400 mg/day (Mayo Clinic)
Select Vital Sign
All Vitals Overview
Heart Rate: 76 bpm
💡 Values based on our study results: 47 participants, measured pre & 30 min post-consumption
Subjects & Methods
Study design, measurement tools & statistical analysis
Study Protocol
Study Design
Pre-post experimental (within-subject) design assessing acute effects of a single energy drink session.
Inclusion Criteria
Healthy adults 18–45 years, both sexes, willing to participate, no chronic diseases or medications affecting CV/cognitive function.
Physiological Tools
Mercury sphygmomanometer (BP), thermometer (temp), manual heart rate & respiratory rate counting.
Cognitive Battery
Mindfulness Scale, Paired Associate Learning (21 pairs), Digit Span, Digit Subtraction, Timed Arithmetic.
Statistical Analysis
SPSS v26. Paired t-test for pre-post comparison. Descriptive stats: Mean ± SD, frequencies & percentages.
Ethics
Written informed consent from all participants. Data anonymized. Voluntary participation with right to withdraw.
Discussion
Our findings compared with existing scientific literature
Cardiovascular Effects
- Significant post-consumption increases in HR, SBP, DBP, RR, and temperature (all p < 0.001)
- Aligns with Grasser et al. (2014): healthy adults consuming Red Bull showed significant BP & HR elevation
- Shah (2019) reported significant cardiovascular stimulation consistent with our findings
Cognitive Outcomes
- Improvements in mindfulness scores, working memory, and processing speed
- Kennedy (2004): caffeine improves alertness, reaction time & working memory
- Haskell CF: improvements in attention switching & subjective alertness
Adverse Effects
- Palpitations, anxiety, insomnia, dizziness & headache reported by 30.4% of participants
- Seifert SM identified palpitations & sleep disturbance as common adverse effects
- EFSA confirmed caffeine-containing drinks frequently cause adverse CV events
Integrated Interpretation
- Coexistence of cognitive enhancement with measurable cardiovascular stimulation
- WHO highlights public health concerns, especially for young people
- Dose-response relationship: low-moderate caffeine (50–200mg) improves alertness without major adverse effects
Strengths
- Standardized pre-post measurement protocol
- Simultaneous assessment of physiology & cognition
- Validated cognitive assessment battery
- Locally relevant Egyptian context evidence
Limitations
- Relatively small sample size (47 participants)
- Absence of a control group
- Individual caffeine tolerance not controlled
- Single-center study limits generalizability
Conclusion & Recommendations
Conclusion
This study revealed statistically significant increases in heart rate, blood pressure, respiratory rate, and temperature after energy drink consumption. Participants showed improvements in attention, reaction time, and cognitive performance. Despite these short-term benefits, the observed cardiovascular changes highlight potential health concerns, particularly with frequent or excessive use. Energy drinks may provide transient cognitive enhancement; however, their consumption is associated with measurable physiological changes that warrant caution.
Recommendations
Public Health Awareness
Educational programs about physiological effects and risks of excessive energy drink consumption
Moderation
Limit intake and avoid frequent or high-dose consumption, especially adolescents and young adults
Clinical Screening
Healthcare professionals should inquire about energy drink use during routine clinical assessments
University Policy
Promote healthier alternatives: adequate sleep, proper nutrition, and regular exercise
Future Research
Studies with larger samples and longer follow-up to assess long-term cardiovascular & cognitive effects
Test Your Knowledge
5 questions from our research
How much caffeine does a typical 250ml energy drink contain?
Research Team
Fifth Year Students – Group 6 – Faculty of Medicine, Suez University
Supervisors
Prof. Dr. Maysa Ibrahim
Direct Research Project Supervisor
Dr. Mohammed Wagih Saleh
Direct Research Project Supervisor
Dr. Nanees Kamel Hussein
Direct Research Year Supervisor
Dr. Yosra Saeed Abdalla
General Research Projects Supervisor
Team Members
16Rehab Shaban
Team LeadMahmoud Attia
Mahmoud ElSayed
Fatma Ali
Abd ElRahman Mostafa
Kyrollos Ashraf
Salah Mohammed
Ahmed Shaban
Mahmoud Eldoreay
Laila Roshdy
Nagwa Adel
Fatma Saad
Abd ElRahman Mahmoud
Mohamed Abd Elhady
Mohammed Elshahat
Deng Ajou Luol