In a recent review published in Nutrients, researchers examine the reported effects of consuming energy drinks on human health, particularly the cardiovascular and nervous systems.

Study: The Dark Side of Energy Drinks: A Comprehensive Review of Their Impact on the Human Body. Image Credit: Pheelings media / Shutterstock.com

Background

The aggressive promotion of energy drinks as a conveyable source of energy and stimulation by beverage firms, combined with their widespread availability in grocery stores, gas stations, and other shops, has increased their consumption amongst young adults and adolescents. Lots of these energy drinks are related to claims that they will improve focus and concentration, increase energy levels, and enhance scholarly or physical performance.

Current popular energy drinks often include large amounts of caffeine, added sugars, and legal stimulants resembling guarana, taurine, and L-carnitine. The rise of the energy drinks market amongst young children and adolescents has inevitably increased their caffeine consumption levels by as much as 70% between 1977 and 2009.

Recent reports suggest a rising incidence of individuals in search of medical care after consuming energy drinks for mild adversities, resembling gastrointestinal disturbances and dehydration, together with more severe outcomes like stroke. Several fatalities linked to energy drink use have also been reported.

Energy drinks likely confer some short-term advantages; nonetheless, researchers need to look at their long-term consequences on human health amid rising reports of their adversarial effects.

Concerning the study

In the current study, researchers screened PubMed, Google Scholar, and EBSCO search engines like google and yahoo to discover original research articles and case reports/series published between January 5, 2009, and April 30, 2023, reporting the consequences of acute or chronic abuse of energy drinks on humans. Case-control studies utilizing animal models were also included within the evaluation. 

Study findings

A complete of 96 scientific papers were included within the evaluation, 35, 12, 18, seven, and two of which reported the consequences of energy drink consumption on cardiac, gastrointestinal, neurologic, renal, gynecological, autoimmune, and skin systems, respectively.

Nine cases of cardiac arrest were related to high doses of stimulants in energy drinks. Furthermore, energy drink consumption was primarily related to cardiac arrhythmias, resembling ventricular fibrillation and previously unrecognized channelopathies. Several cases during which patients with no known medical conditions suffered acute cardiac events after consuming a number of 250 mL cans of energy drinks were also reported.

Three individuals died on account of sudden cardiac arrest, whereas six required intensive cardiopulmonary resuscitation and exhibited no cardiac abnormalities during follow-up visits.

Caffeine was often implicated in energy drink-related chronotropic and inotropic effects on the guts. At higher and really high concentrations of 10 micromolar (µM) and 100 µM, respectively, caffeine directly increased calcium uptake by increasing cyclic adenosine monophosphate (cAMP) and reduced calcium sequestration by the sarcoplasmic reticulum, respectively. 

Every 100 mg of caffeine increased systolic and diastolic blood pressure by 0.8 and 0.5 mmHg, respectively. Many previous studies have conclusively demonstrated how caffeine induces arrhythmias in individuals with atrioventricular conduction disorders.

The high caffeine content of energy drinks has also been related to many adversarial effects on the central nervous system (CNS), including seizures, manic psychosis, and cerebral vasculopathy. In a single study, echoencephalography (EEG) demonstrated that caffeine intake from energy drinks increased left frontal activation to a greater extent than the correct frontal lobe, thus suggesting that energy drinks mimic the effect of dopamine on striatopallidal neurons to cut back fatigue. 

Lower than 500 mg of caffeine has been shown to extend alertness, speed of thoughts and speech, diminished fatigue, and reduced sleep. Nevertheless, higher doses of caffeine likely contribute to anxiety, insomnia, tremors, and seizures.

The chronic consumption of energy drinks has been related to stress, anxiety, and depression. These effects are likely on account of the power of taurine to mimic gamma-aminobutyric acid (GABA) and the anticonvulsant effects of glycine.

All energy drinks contain vitamins. Notably, a dose-dependent effect of vitamin B3 (niacin) has been implicated in hepatotoxicity, wherein its megadoses initially caused a gentle elevation of liver enzymes, hepatic steatosis/necrosis, and, in rare cases, liver failure.

In vivo studies have similarly reported acute and chronic toxicity related to energy drink consumption. In a single study evaluating the consequences of energy drinks in rabbits, a direct correlation was observed between brain, liver, kidneys, and heart tissue damage and energy drink dose.

Conclusions

The European Food Safety Authority (EFSA) has set an upper secure intake limit of 400 mg/day of caffeine in adults. Since caffeine is the essential component of energy drinks, precise limits on the consumption of those drinks are warranted. 

The long-term effects of energy drinks are unclear; nonetheless, their consumption may cause psychiatric pathologies or aggravate cardiac conduction disorders in minors. Thus, although energy drinks contain legal substances, their consumption and sale needs to be strictly regulated, especially for minors. Pregnant or breastfeeding women must also avoid these products altogether to avert possible long-term adversarial effects of energy drink consumption on their unborn child.