Energy drinks have become a new niche in the beverage market bolstered after the introduction of Red Bull in 1987. They are widely used especially within the younger population. Approximately one-third of teens and young adults regularly consume energy drinks, and more than half of college students have reported consuming more than one energy drink per month.
According to the Food and Drug Administration, the allowable limit for caffeine is 0.02% (i.e., 71 mg maximum per 12 fluid ounces) for cola-type beverages (i.e., Classic Coca-Cola has 34 mg of caffeine per 12 fluid ounce). However, this has not been extended to energy drinks. Although a standard definition of energy drink does not exist, they are distinguished from sports and nutraceutical drinks in that they contain caffeine in conjunction with presumed energy-enhancing ingredients, such as taurine, B vitamins, and other herbal extracts. Claims of benefits include improvements in alertness, aerobic and anaerobic endurance, concentration, memory, and reaction time. In the United States, energy drinks hold 63% of the market share for nonalcoholic beverages, estimated to be a $5.4 billion industry in 2006, with 47% of the market internationally.
But what about safety?
Despite the enormous popularity of energy drinks, the safety profile of these beverages is unknown. Consumption has been linked to 34 deaths and over 20,000 emergency room visits. Also, the Poison Control Center reported the majority of cases had to do with cardiovascular (including an abnormal heart rhythm and conduction abnormalities) and neurologic effects (seizures, including status epilepticus). The FDA released an advisory in 2012 cautioning consumers that energy drinks are not alternatives to rest or sleep and that people should consult their healthcare provider prior to consumption.
A meta-analysis of 15 clinical trials that included nearly 340 people showed that energy were associated with an increase in systolic and diastolic blood pressure by nearly 5 and 3 mmHg, respectively. Though this degree of change is not alarming for a healthy individual in an acute setting, it could be concerning if the blood pressure elevations are sustained for a longer period of time. Furthermore, this degree of change is clinically significant in those with hypertension. As would be expected, consuming a high dose of energy drinks could result in a greater blood pressure elevation and could be a potential cause for a hospital visit. Studies have also shown that caffeine-naive individuals may have a heightened blood pressure response.
In addition to blood pressure changes, data have also suggested changes in the heart rhythm. Based on a couple previous studies by Shah and his team along with a review of published cases, it appears that energy drinks affect the QTc interval, which is a marker measured on the electrocardiogram indicative of fatal cardiac arrhythmias. However, more studies are needed to further validate these findings at different doses and populations.
Crowdfunding a study on energy drinks and blood pressure
Researchers from University of the Pacific are raising funds through a crowdfunding campaign on http://go.pacific.edu/energydrinks to conduct the largest clinical trial evaluating the long-term effects of energy drink consumption on central and peripheral blood pressure. The research team is aiming to reach a goal of $50,000 to run a large randomized, blinded, controlled trial otherwise known as the gold standard of study designs, to study the impact of long-term energy drink consumption on blood pressure. It is important to know if energy drinks raise blood pressure in a sustained manner, as even small elevations at a population level can increase the risk of hypertension and stroke. For example, torcetrapib, a new drug from Pfizer was stopped from further development for having a 3-4 mmHg increase in systolic blood pressure.
Primary investigator Sachin A. Shah, PharmD, Associate Professor of Pharmacy at the University of the Pacific’s Thomas J. Long School of Pharmacy and Health Sciences, and his team have been performing energy drink-related research for over 5 years. Dr. Shah and team are now looking to understand the effects of long-term energy drink consumption on human health. Shah is passionate about this project as it would truly be a “publicly funded project to answer a public-health question.” The research team is open to listening to thoughts and opinions of people who engage with the project. Also, they are offering credit and perks to those that donate to the cause.