Effects of Chronic Energy Drink Consumption on Cardiometabolic Endpoints

The popularity of energy drinks (EDs) have increased over the last few decades due to their purported benefits as mental and physical performance enhancements. While caffeine is a major ingredient in most EDs (ranging from 80 mg to 500 mg per drink), they may also contain various supplements, such as guarana, taurine, ginseng, B vitamins, gluconolactone, yohimbe, carnitine, and bitter orange, as well as high amount of sugar (ranging from 25-50 grams). The United States Food and Drug Administration (FDA) has cited that a daily intake of 400 mg caffeine (approximately 4-5 cups of coffee) in adults is generally safe and not associated with dangerous, negative effects. The Substance Abuse and Mental Health Services Administration reported a doubling of emergency department visits involving EDs from 10,068 visits in 2007 to 20,783 visits in 2011. Commonly reported adverse reactions include insomnia, nervousness, headache, tachycardia, and seizures. Currently, the health effects of long-term ED use remain unknown.

This study is a proof-of-concept, prospective trial that aims to evaluate the effects of chronic ED consumption on cardiometabolic parameters in a healthy population. Subjects will consume two cans (16 oz.) of an energy drink daily for 4 weeks. The study will assess any changes in blood pressure (BP), electrocardiographic (ECG) parameters, blood glucose, cholesterol, weight, body mass index (BMI), and body fat composition before and after consuming EDs for 4 weeks.

Inclusion criteria

• Healthy adults aged 18 - 40 years
• Participants willing to adhere to study drink schedule (28 days)

Exclusion criteria

• Naïve caffeine consumers (< 2 cups of coffee [or equivalent caffeine intake] per week)
• Chronic medical conditions including cardiovascular disease (known history of cardiac arrhythmias, family history of premature sudden cardiac death before age 60, cardiomyopathy, atherosclerosis), smoking, renal or hepatic dysfunction
• Prolonged corrected QT (QTc) interval
• History of substance abuse, including alcohol
• Concurrent use of prescription drugs or over-the-counter products that may interact with study drinks (with the exception of oral contraceptives that have been used for over 1 month)
• Baseline Blood Pressure greater than 140/90 mmHg
• Baseline fasting blood glucose greater than 126 mg/dL or random blood glucose greater than 200 mg/dL
• Females only: pregnancy or lactation, or planning to get pregnant within next 28 days