Energy Drinks

What energy drinks contain

Energy drinks are functional beverages formulated to boost mental alertness and physical performance. A typical 250ml can contains 80-300mg of caffeine, often combined with taurine, B-vitamins, and either sugar or artificial sweeteners ^[1]. The caffeine content alone can exceed the amount in three cups of coffee, creating a potent stimulant effect on the central nervous system.

Cardiovascular effects

Research shows that energy drink consumption produces measurable cardiovascular changes. A 2024 meta-analysis of randomized controlled trials found that these drinks increase systolic blood pressure by 4.7 mmHg and diastolic pressure by 4.5 mmHg within 60-120 minutes of consumption ^[2]. While these changes are temporary in healthy adults, they may pose risks for individuals with hypertension or existing heart conditions. Cardiac output also rises, suggesting the heart works harder to maintain circulation after ingestion.

Common adverse effects

A comprehensive systematic review analyzing 32 studies and over 96,000 participants identified the most frequently reported side effects ^[1]. In adults, these include insomnia (24.7%), jitteriness and restlessness (29.8%), and gastrointestinal upset (21.6%). The odds of experiencing insomnia are five times higher with energy drink consumption compared to control groups. Adolescents face similar issues, with stress and depressive mood also commonly reported.

Sleep disruption

The high caffeine content significantly disrupts sleep architecture. Studies demonstrate that consuming energy drinks even six hours before bedtime can reduce total sleep time and impair sleep quality ^[3]. This creates a counterproductive cycle where poor sleep leads to daytime fatigue, prompting further energy drink use the following day.

Mixing with alcohol

Combining energy drinks with alcohol masks the sedative effects of alcohol while maintaining its impairment. This leads to increased risk-taking behavior and higher overall alcohol consumption, as individuals feel less intoxicated than they actually are ^[1]. The practice is particularly common among young adults and is associated with more frequent binge drinking episodes.

Regulatory recommendations

Based on the available evidence, health authorities recommend limiting energy drink intake to fewer than five per week ^[1]. Children, adolescents, pregnant women, and individuals with cardiovascular conditions should avoid these beverages entirely. For healthy adults seeking performance enhancement, moderate caffeine intake from coffee or tea presents a safer alternative with better-studied long-term safety profiles.