Abstract
Purpose of Review
From the introduction of the popular energy drink “Red Bull” in 1997 to the United States, energy drink consumption has rapidly grown and evolved. In the last decade, in particular, these beverages have been considered a potential health hazard. This is due to their large concentrations of caffeine in addition to other components such as taurine, B vitamins, guarana, l-carnitine, and ginseng that have individual risk as well as potential synergistic risk with other ingredients.
Recent Findings
This review focuses on the evolving market of energy, typical “active” components of the most used drinks, and their potential effects on health, particularly cardiovascular risk. The most often consumed products are analyzed for their caffeine content and by their key active ingredients. These ingredients are then considered based upon their potential for cardiac risk alone and in combination with others.
Summary
When used within the recommended dosage, all these components of energy drinks have no to very rare reported adverse health impacts. However, intoxication can occur upon prolonged and excessive consumption of energy drinks and in with consumption of other products. Furthermore, potential vulnerable populations (ex., youth, pregnant women, and those with cardiovascular conditions) should limit consumption of energy drinks, pending further research.
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Introduction
Energy drink consumption is on the rise. The energy drink market was estimated at 8.25 billion US dollars in 2018 and is projected to increase to 10.91 billion by 2023 in the USA [1].
With the rise in consumption that is increasing worldwide, there has been an increase in reported cases of intoxication leading to cardiovascular events, including arrhythmias and seizures. Along with the rise in consumption, there has been a rise in emergency room visits attributed to energy drink consumption. The Substance Abuse and Mental Health Services Administration has reported that emergency room visits associated with energy drink consumption have doubled from 10,068 visits in 2007 to 20,783 visits in 2011 [2]. Of this 206% increase, more emergency room visits were observed in 18–39-year-old males than any other demographic. The consumption of energy drinks has become a public health concern as a growing body of evidence documents various harmful effects these drinks have incurred.
Although “energy drinks” have existed since the 1960s, the introduction of “Red Bull” in the United States in 1997 sparked the growing trend in consumption. Since this initial introduction, over 500 new energy drinks have been launched worldwide, some of the most prominent being Red Bull, Monster, and Rockstar, making up over 80% of the industry in 2006. [3] These drinks vary widely in caffeine content, ranging from 50 to 505 mg per container. [4] While the principal ingredient in energy drinks is caffeine, other common substances include in isolation and combinations that include taurine, B complex vitamins, guarana, l-carnitine, and ginseng. [5] The acute and chronic effects resulting from excessive consumption of these beverages are still not fully known and pose a potential for adverse health consequences that should be considered and may be cause for regulatory action. In addition, it is unknown if these different substances and ingredients may synergistically impact inherent risks.
This updated review was undertaken in a rapidly evolving marketplace of energy drinks to explore the current trends with respect to energy drinks and their components, to evaluate evidence surrounding adverse health impacts (in particular cardiovascular events), and to offer potential management strategies.
The Current Situation Surrounding Energy Drinks
Energy drinks are marketed broadly to promote energy as well as mental and physical endurance and performance. According to the National Center for Complementary and Integrative Health (NCCIH), energy drinks have been found to improve physical endurance in some cases. However, there is less support for impacts on muscle strength. Energy drinks often contain high levels of caffeine and may also include other enhancing additives, such as sugar, taurine, carnitine, B vitamins, and guarana, a plant product containing concentrated caffeine. [6] Energy drinks can be classified as dietary supplements and are the second most popular supplement for men between 18 and 34 years old. Likewise, energy supplements are commonly used among teenagers (12–17 years), with nearly one-third reporting use in this demographic. [7, 8]
There are two kinds of energy drinks, energy shots that are generally 2–2.5 oz in size and energy drinks that are generally 8–16 oz in size. Energy shots are concentrated liquid and contain approximately 113–200 mg of caffeine. Energy drinks (8–16 oz) contain approximately 50–500 mg of caffeine. [4] As noted, the amount of caffeine can vary widely between energy drinks, and the exact amount of caffeine in a given product may not be easy to identify. This extreme variety may be partly because there is no requirement to report the amount of caffeine in these products. For comparison purposes, the caffeine contained in a cup (8 oz) of coffee is approximately 100 mg, and a bottle of cola (12 oz) is 35 mg. [9, 10] While caffeine is a significant component of energy drinks and has raised safety concerns, other components previously mentioned have also begun to be controversial and raise concerns.
Common Potential Stimulants in Energy Drinks
Caffeine
Caffeine, a methylxanthine, is a naturally occurring mild stimulant that has often been touted as an energy enhancer through increased sympathetic nerve activity. Caffeine can produce a subjective reinforcing and discriminative stimulus similar to those produced through dopamine by cocaine and amphetamines. [11] Upon consumption, caffeine rapidly absorbs in the body, reaching peak plasma levels within 30 min of consumption. [12] At high doses, caffeine can disseminate throughout the body passing through the blood–brain barrier and the placenta in pregnant women increasing risk for low birth weight infants and spontaneous abortion. [13•, 14•] The US Food and Drug Administration (FDA) considers up to 400 mg of caffeine a safe amount for adults and 200 mg for pregnant women. [15] While the FDA has not set guidelines for safe consumption in children, the Canadian government recommends the following limits: ages 4–6: 45 mg, ages 7–9: 62 mg, and ages 10–12: 85 mg. In adults, high doses (> 400 mg) of caffeine can lead to increased anxiety, nausea, jitters, and nervousness. [16] These adverse effects were also observed in children at lower doses (100–400 mg). [17•]
Caffeine acts as a competitive phosphodiesterase inhibitor, leading to an increase in cyclic AMP and, consequently, positive inotropic action on the myocardium raising cardiac output and blood pressure. [18] Evidence suggests that energy drinks may improve reaction time and physical performance by attenuating the decrease in skill performance caused by sleep deprivation. [19] Furthermore, it has been reported that caffeine may act as a natural antioxidant by preventing oxidative stress. This effect can improve physical performance and may serve as a protectant against cardiovascular damage and help prevent cancer. That being said, there is little evidence to suggest that caffeine alone contributes to decreased cancer risk due to similar results reported in other compounds that act as antioxidants. [12]
Taurine
Taurine is a conditionally essential amino acid. It is one of the highest concentrated free amino acids in the human body and accounts for 0.1% of the human body weight, with most of the amino acid being located in the leukocytes, heart, muscle, retina, kidney, bone, and brain. [20] This is due to its role in modulating contractile function. Taurine increases force generation within the muscle by enhancing the sarcoplasmic reticulum’s calcium accumulation and release. It is theorized that muscle fibers may modulate their contractility by modifying taurine levels in response to neural stimuli. [21] Taurine deficiency has been associated with a decreased sensitivity of cardiac muscle to Ca2 + decreasing inotropic capability. This finding has led to the argument that taurine supplementation may improve physical performance by increasing blood supply to organs, especially the musculoskeletal system. [22•].
Taurine is a principal ingredient in many energy drinks and caffeinated beverages (Table 2). When combined with caffeine, taurine displays a synergistic effect that increases athletic and mental performance consume. [22•] The European Commission of Health and Food Safety suggests that the consumption of taurine in humans, on average, ranges from 40 to 400 mg/day. [23] Studies suggest frequent consumption of taurine at concentrations above 400 mg/d results in taurine accumulation in the plasma. It also leads to slight increases in whole blood taurine levels. [24] Nevertheless, studies at this time have found no side effects from excessive intake of taurine, although there is a likely upper bound in which these may become manifest. By contrast, in the case of taurine deficiency, retinal abnormalities and decreased cardiac inotropic capability may occur. [25, 26]
B Complex Vitamins
B vitamins (thiamine, riboflavin, niacin, pantothenic acid, pyridoxine hydrochloride, biotin, inositol, and cyanocobalamine) are often found in large quantities in energy drinks and in higher concentration than the recommended daily intake. B vitamins serve as coenzymes for cellular and mitochondrial function, including energy production, which has led some to believe B vitamins may increase energy expenditure. [27] A study in 2019 found that the excessive consumption of B vitamins is not metabolically inert. Instead, it resulted in a 24% increase in insulin secretion, differential hormone secretion, and elevated one-carbon flux to process the load placed by the vitamins. [28]
Guarana
Guarana has a high-caffeine content. The amount of caffeine in its seeds ranges from 2.3 to 7.8%. [29] The amount of caffeine is higher in guarana seeds compared to coffee beans, which contain 1 to 2%. [30]
The FDA generally recognizes guarana as safe, but they have not determined the amount considered safe to consume. [31] Because of this, the amount of caffeine in products containing guarana can be assumed to be larger than listed. For example, in a recent study, the authors noted that an energy drink containing guarana reported the caffeine concentration as 19.5 mg/100 mL. [32••] However, after the authors performed a chemical analysis on this energy drink, they found the caffeine concentration to be higher at 27.42 mg/100 mL, an increase of 40.62% from the reported value. Out of the 50 energy drinks evaluated in this study, only three were found to have caffeine concentrations within 2 mg of the reported values. [32••] Several of these drinks were found to have caffeine concentrations more than double their reported values.
l-Carnitine
l-Carnitine, a naturally occurring amino acid, is primarily manufactured by the liver and kidneys. It has a role in B-oxidation as a carnitine-dependent transporter of fatty acids, impacting metabolism and energy production. [18] The cellular uptake of l-carnitine occurs by stimulation of hematopoiesis, inhibition of collage-induced platelet aggregation, and prevention of programmed cell death in immune cells. [33] As a result, l-carnitine has shown promise for its use in training, competition, and recovery during times of strenuous physical activity.
While supplementation at safe doses may be beneficial during strenuous activity, high doses of l-carnitine may lead to increased platelet aggregation in patients with sarcopenia and thromboembolic phenomena. [34, 35] In addition, l-carnitine has been found to accelerate atherosclerosis via trimethylamine conversion to trimethylamine-N-oxide in a mice model. [36]
Ginseng
Asian ginseng reduces lactic acid metabolism, which has been shown to enhance physical endurance. [37] This finding may be attributed to ginseng extract that has a direct vasodilatory effect on blood vessels. Furthermore, ginseng extract is currently being investigated as a potential treatment for hypertension. [38] The vasodilatory effect of ginseng is due to its regulation of calcium and nitric oxide pathways. [39]
The recommended dose for ginseng is about 3 g/ day (Lee et al., 2012). The maximum dose considered safe is 9 g/day. [40] It has been found that individuals consuming 15 g of ginseng per day over prolonged periods of time can develop “ginseng abuse syndrome” characterized by depersonalization and confusion. [41] In a separate case study, a woman who consumed 25 g of ginseng per day reported nausea, vomiting, and cerebral arteritis. [42] Given the broad use of ginseng, it should be noted, however, that negative outcomes from prolonged and/or excessive ginseng consumption is generally considered low risk. [40] Nevertheless, more research on ginseng consumption is needed to establish safe use practices.
Energy Drink Sales
Sales of energy drinks have grown around 5% every year since 2013, within the 8–16-oz variety of energy drinks listed in Table 1. [43] Red Bull leads the Market with $2891 million in sales, followed by Monster Energy with $1763 million in sales.
Table 2 shows the top brands with their associated concentrations of caffeine followed by the next active ingredients used to enhance the energy drink.
Potential Cardiovascular Risk with Contemporary Common Energy Drink Ingredients
Caffeine
It is widely thought that caffeine, particularly at high concentrations, is associated with multiple cardiac risks such as palpitations, atrial fibrillation, and supraventricular and ventricular ectopy. These multiple conditions are thought to be caused by caffeine’s effect of acutely raising blood pressure. This elevation in blood pressure has been shown to be more prominent in the elderly and those with underlying hypertension. Although these demographics have more prominent symptoms, one study found that ingestion of a 355 mL can of Red Bull in young adults increased systolic BP by approximately 10 mmHg, diastolic BP by approximately 7 mmHg, and heart rate by 20 beats/min. [44] These effects can be exacerbated by the average 4–6 h half-life of caffeine, creating ample opportunity for further intake of energy drinks with dose augmentation. [45, 46]
A comparative epidemiologic study of 347,077 patients in the UK Biobanks showed a slight increase in risk of general cardiovascular disease in patients with habitual, heavy coffee consumption compared to those drinking 1–2 cups per day. In this analysis, drinking > 6 cups per day increased risk by 22%, which was also increased by 11% in nondrinkers, and 7% in those that drank decaffeinated coffee; this association was unaffected by genetic variants influencing caffeine metabolism. [47]
However, there are also well-documented benefits to caffeine consumption as it has been reported to lower the risk for obesity, a cardioprotective measure. This association was found in an upward curve, with higher doses of caffeine increasing heart failure and low/normal doses proving beneficial. [48] There is some evidence that coffee metabolism can aid weight loss, lowering obesity rates and risk of cardiovascular disease. However, genetics, age, sex, liver function, and medication can influence absorption rates. This range in absorption rates is due to the fact that the effects of caffeine in coffee vary. There is minimal evidence that caffeine derived from sources other than coffee is effective in reducing the incidence of obesity, implying the possibility that other components of coffee are responsible for this correlation.
Next to alcohol, caffeine is one of the most commonly reported triggers of palpitations and atrial fibrillation. In a study of 1295 patients with atrial fibrillation, 28% reported caffeine was a trigger. [49••] However, there is a divergence in risk when objective measurements are used to link caffeine consumption and arrhythmia risk compared to patient-reported risk. For example, the female sex, Hispanic ethnicity, obstructive sleep apnea, and those with a family history of atrial fibrillation were associated with greater triggers. As these risk factors, Hispanic ethnicity seems to be at the greatest risk. [49••] An example of divergent risk was observed in another study using the UK Biobanks involving 386,258 habitual coffee consumption as previously defined was associated with a 3% lower risk of clinical atrial fibrillation and flutter. This benefit persisted in consideration of 7 common polymorphisms of hepatic caffeine metabolism. [50••]
In regard to ventricular arrhythmias, in a small study of 22 patients that ingested 275 mg of caffeine in coffee, there was no observed increased in risk towards ventricular arrhythmias during an electrophysiology study. [51••] In support of this observation, in a study of 1388 participants, it was found that there was no relationship observed between premature ventricular contractions and premature atrial contractions with moderate caffeine usage (< 275 mg). [52] These studies suggest with at least moderate consumption there is not a clear arrhythmia risk with caffeine and the discrepancy of these outcomes with those in which patients report caffeine is a common trigger of arrhythmia requires additional study. It is possible that some of this discrepancy is influenced by how caffeine impacts sleep quantity and quality.
Regarding potentially toxic doses (> 400 mg) of caffeine have been documented to affect the conductance and refractoriness of the heart leading to arrhythmia, in particular, delayed afterdepolarizations through the release of calcium from the sarcoplasmic reticulum. [53] A systematic review of various case studies reported arrhythmias, coronary vasospasm, aortic aneurysm dissection, cardiac arrest, QT prolongation, acute coronary thrombosis, and ST-elevation myocardial infarction related to energy drink consumption. [54] Among those with negative cardiovascular outcomes, 35% were related to arrhythmia.
Taurine
Congestive Heart Failure
Taurine has been approved for the treatment of congestive heart failure in Japan. [55, 56] The primary therapeutic benefit of taurine is through the reduction in the action of norepinephrine and angiotensin II, both of which decrease myocardial performance through elevation in afterload pressure, ventricular remodeling, and fluid remodeling. [57] Additionally, there is evidence to support the idea that taurine elevates high energy phosphate content in the heart, an additional determinant of mortality among patients suffering from congestive heart failure. [56] It should be noted that in one study by Huxtable and Bressler, taurine was found in higher concentration in the left ventricle of patients who died of congestive heart failure compared to those who died of other causes with no cardiovascular history. [58] This may suggest that taurine may have a negative inotropic effect. However, more recent research has shown the opposite, with taurine exerting a mild positive inotropic effect on the hyperdynamic heart as well as promotion of natriuresis and diuresis. [57]
Hypertension
Supplementation with taurine has been noted in the reduction of blood pressure and hypertension risk. This process appears to be mediated by a combination of diminished calcium concentrations, oxidative stress, sympathetic activity, inflammatory activity, and improvement in renal function through the promotion of diuresis. [59] It has been suggested that the dietary intake of taurine likely prevents the progression of cardiovascular diseases by repairing impaired endothelial function. Taurine supplementation has also been shown to significantly reduce blood pressure and improve vascular function in prehypertensive individuals, particularly those with high-normal blood pressure. [60]
Synergistic Effect of Taurine and Caffeine
A double-blind study performed by Baum and Weiss [61] examined the cardiovascular impact of the consumption of beverages containing both taurine and caffeine. It was found that cardiac contractility, particularly of the left atrial contractility post-exercise, was increased. These findings provide support for improved maximal performance and lower heart rate at submaximal working intensity as observed in previous studies. [61] Moreover, taurine potentially reduces the cardiovascular effects of caffeine. [59]
In a study of 50 volunteers, it was found that following consumption of high-caffeine energy drink (250-mL sugar-free energy drink containing caffeine (80 mg), taurine (1000 mg), and glucouronolactone (600 mg), or 250 mL carbonated water (control), there was a significant increase in platelet aggregation compared to the control (13.7 ± 3.7% vs. 0.3 ± 0.8%). When alcohol was mixed with the energy drink, the findings were exacerbated. In multiple case studies, sudden cardiac death, coronary vasospasm, and coronary thrombosis have been documented 1–2 h after consuming energy drinks mixed with alcohol. [62•] It appears that mixing alcohol with energy drinks is more common among the college population. It has been reported that 51% of college students have consumed at least one energy drink per month, and of those consumers, 54% had mixed it with alcohol. [62•]
Due to the variability of the ingredients in energy drinks, it is difficult to know which component is responsible for increased platelet aggregation. In addition, the exact mechanism of this phenomenon is unknown. However, it appears that some ingredients may also have a cardioprotective effect. It has been found that consumption of taurine leads to reduced platelet aggregation by 30–70%, potentially acting as a protective measure. [63••] This raises the question, are energy drinks that do not contain taurine or insufficient quantities, such as Bang (Table 2), will be more prone to cause platelet aggregation and myocardial infarction risk? This is an area in with further research is critically warranted as ingredients are combined.
B Complex Vitamins
Cardiovascular Disease and Stroke Risk
An association has been found between high dietary intake of folate and pyridoxine hydrochloride leading to a reduction in cardiovascular and stroke risk. [64] On the contrary, another study found that when individuals were given supplemental folic acid, vitamin B12, and vitamin B6, to lower homocysteine there was an increased risk leading to questions surrounding combinations of B complex vitamins. [65] Mechanistically, the association of B complex vitamins and cardiovascular risk may be due to homocysteine. Homocysteine is a sulfhydryl-containing amino acid that may increase risk for developing atherosclerotic vascular disease. [66] B complex vitamins serve as a substrate for homocysteine metabolism, resulting in increased blood homocysteine levels when in low concentration, and a 20% total homocysteine reduction has been associated with a 7% decrease in cardiovascular events (cardiovascular death, myocardial infarction, stroke). [67]
Guarana
As previously discussed, guarana seeds contain much higher levels of caffeine compared to coffee beans. At very high levels, caffeine increases intracellular calcium concentration resulting in noradrenaline release and dopamine receptor sensitization. This pathway causes ventricular tachyarrhythmias, particularly at high doses. [46] Caffeine plasma concentrations of 15 mg/L or higher may lead to poisoning or, in rare cases, death. Caffeine plasma concentrations of 80–100 mg/L are considered lethal. [68] Such high levels were previously most commonly found in diet pills or in individuals who frequently consumed many types of caffeinated beverages. Moreover, the presence of guarana in energy drinks compounds the potential effect of caffeine. Due to the lack of regulation on guarana in energy drinks, the amount of guarana in such drinks ranges from 1.4 to 300 mg, potentially ingesting very high levels of caffeine.18 Overdosing guarana results in irritability, insomnia, anxiety, restlessness, muscle twitching, rapid heartbeat, and diuresis. [69]
l-Carnitine
Cardiovascular Disease and Stroke Risk
A systematic review and meta-analysis of 13 controlled trials concluded that l-carnitine supplementation had been shown to reduce the risk for angina by 40% and ventricular arrhythmias by 65%. [70] It may also increase left ventricular ejection fraction and decrease left ventricular remodeling, as seen in a longitudinal study in which patients treated early post-acute myocardial infarction with l-carnitine resulted in smaller left ventricular volumes compared to the placebo group. In addition, the incidence of death and congestive heart failure after discharge was drastically reduced in the treatment group. [71••] It should be noted that although the amount of l-carnitine added to energy drinks may not be enough to cause toxic effects, l-carnitine in large doses can lead to seizures, nausea, vomiting, abdominal pain, and diarrhea. [7]
Atherosclerosis
Rather than directly impacting atherosclerosis risk, microflora metabolizing l-carnitine has led to increased cardiovascular risk. Microbiota-derived trimethylamine (TMA) and trimethylamine-N-oxide (TMAO) produced by microflora have been found to enhance cardiovascular risk by promoting atherosclerotic lesion development. [36, 72] Increasing evidence suggests a correlation between TMAO and atherosclerosis risk. This relationship, along with l-carnitine, could prove valuable as targets for therapeutic strategies to reduce risk. However, TMAO has been found to promote platelet aggregation and consequent thrombus formation through the augmented release of calcium from intracellular reserves. [73] Further research is needed to evaluate the relationship between l-carnitine, TMA, TMAO, and platelet aggregation on the microbiome level, which may provide an explanation for the increase in platelet aggregation following the consumption of energy drinks. [74]
Ginseng
Long-QT Syndrome
Ginseng is well known for its adaptogenic effect mediated by compounds known as ginsenosides. The intake of 250 mg of ginseng by healthy adults resulted in an increased QTc by 0.015 s. [75] Although statistically significant, this result is not clinically significant for the average adult. However, in susceptible groups with inherited cardiomyopathies, such as long-QT syndrome (LQTS), significant prolongation of the QT may developed such as what was seen in a case of a 13-year-old girl who presented with chest pain and palpitations upon consuming an energy drink with a QTc > 500 ms. [76] Similarly, a 22-year-old female who consumed six cans of energy drinks (80 mg caffeine) who experienced sudden cardiac death was found to have LQTS. [77] Similar amounts of caffeine in otherwise healthy adults have no noticeable effect on QTc. [78]
Hypertension
Rat models have found an increase in insulin sensitivity leading to weight loss and improved serum cholesterol with ginseng supplementation. [79] If such findings can be observed in human models, it could be argued that ginseng supplementation may be cardioprotective. Notwithstanding, the amount of ginseng in energy drinks is likely not enough to produce a beneficial effect. Likewise, the amount of ginseng commonly used in energy drinks is likely not sufficient to cause toxicity, as seen in high intakes of ginseng (> 15 g/day), which have led to “ginseng abuse syndrome” characterized by hypertension. [80]
Management
It is not surprising that energy drink consumption is on the rise. It appeals to most demographics due to expert marketing, the variety in product and flavor, and claim to provide more energy and vitality. However, many consumers are unaware of the difference between energy drinks, soft drinks, and sports drinks. This has led to increased caffeine consumption making caffeine the most commonly ingested psychoactive drug worldwide. The potency of the caffeine contained in energy drinks is heightened by its other ingredients, such as taurine, B vitamins, guarana, l-carnitine, and ginseng.
Examples of concern of mixing ingredients have been shared previously. Potential risks extend to people traditionally felt to be a low risk for cardiac disease. For example, atrial fibrillation is extremely rare in the pediatric population and most commonly occurs in association with structural heart disease. [81] The popularity of energy drinks in the pediatric and adolescent population has led to increased arrhythmogenic potential. Multiple case studies have documented adolescents experiencing atrial fibrillation/atrial tachycardia after consuming energy drinks. [82]
Although taurine and l-carnitine have shown to be cardioprotective, guarana and caffeine combined may lead to adverse health outcomes. When high levels of caffeine are consumed in cases where underlying cardiovascular disease is present, there is increased probability that significant decrease in perfusion may occur resulting in myocardial ischemia, infarction, and arrhythmias. [83] Examining the relationship between energy drink consumption and cardiovascular risk is necessary to prevent future cardiovascular events.
While energy drink consumption is generally considered safe, many do not understand what the potential risks associated with consumption and what could be considered safe consumption practices. Misinformation surrounding energy drinks can be negated by regulations requiring products to inform the consumer of side effects as well as warnings for children, adolescents, pregnant women, and those with existing cardiovascular conditions. In addition, energy drinks should be required to calculate the caffeine concentration of not only the added caffeine but also the amount of guarana it contains to better inform consumers of the actual concentration of caffeine.
Conclusion
Energy drinks and their components raise concerns about the short- and long-term risks for cardiovascular events as they evolve and continue to combine “active” ingredients. These concerns have increasingly led to a range of restrictions and recommendations for conception, and as well as stricter requirements for product labeling. The FDA has been actively investigating the impact of energy drinks, but, due to a lack of data, has only been effective at regulating limits on the amount of caffeine allowed per serving and mandatory labeling of caffeine content. Although the evidence for harm from energy drinks is incomplete, the potential for public health concern should elicit further research into the various components of energy drinks and their synergistic effects. Furthermore, vulnerable populations (ex., youth, pregnant women, and those with cardiovascular conditions) should limit the consumption of energy drinks, pending further research.
References
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
Chakravarty S. Top energy drink companies in the U.S. | Market Research Blog. Market Research Reports® Inc.; 2019. https://www.marketresearchreports.com/blog/2019/07/29/top-energy-drink-companies-us. Accessed 12/4/2022.
Mattson ME. Update on emergency department visits involving energy drinks: a continuing public health concern. The CBHSQ Report. Rockville (MD)2013:1–7. https://www.ncbi.nlm.nih.gov/books/NBK384664/.
Johnson CK. Caffeine-stoked energy drinks worry docs. Washington Post; 2006.
Reissig CJ, Strain EC, Griffiths RR. Caffeinated energy drinks–a growing problem. Drug Alcohol Depend. 2009;99(1–3):1–10. https://doi.org/10.1016/j.drugalcdep.2008.08.001.
Aranda M, Morlock G. Simultaneous determination of riboflavin, pyridoxine, nicotinamide, caffeine and taurine in energy drinks by planar chromatography-multiple detection with confirmation by electrospray ionization mass spectrometry. J Chromatogr A. 2006;1131(1–2):253–60. https://doi.org/10.1016/j.chroma.2006.07.018.
Woods DJ. Guarana: Paullinia cupana, P. sorbilis; also known as Brazilian cocoa and ‘zoom’. J Prim Health Care. 2012;4(2):163–4. https://www.ncbi.nlm.nih.gov/pubmed/22675703. Accessed 12/4/2022.
Seifert SM, Schaechter JL, Hershorin ER, Lipshultz SE. Health effects of energy drinks on children, adolescents, and young adults. Pediatrics. 2011;127(3):511–28. https://doi.org/10.1542/peds.2009-3592.
Committee on N, the Council on Sports M, Fitness. Sports drinks and energy drinks for children and adolescents: are they appropriate? Pediatrics. 2011;127(6):1182–9. https://doi.org/10.1542/peds.2011-0965.
McCusker RR, Goldberger BA, Cone EJ. Caffeine content of energy drinks, carbonated sodas, and other beverages. J Anal Toxicol. 2006;30(2):112–4. https://doi.org/10.1093/jat/30.2.112.
Rogers PJ, Richardson NJ. Why do we like drinks that contain caffeine? Trends Food Sci Technol. 1993;4(4):108–11.
Garrett BE, Griffiths RR. The role of dopamine in the behavioral effects of caffeine in animals and humans. Pharmacol Biochem Behav. 1997;57(3):533–41. https://doi.org/10.1016/s0091-3057(96)00435-2.
Escott-Stump S. Nutrition and diagnosis-related care: Wolters Kluwer. 2008
Rhee J, Kim R, Kim Y, et al. Maternal caffeine consumption during pregnancy and risk of low birth weight: a dose-response meta-analysis of observational studies. PLoS One 2015;10(7):e0132334. https://doi.org/10.1371/journal.pone.0132334. Important meta-analysis on the potential risk of caffeine to both the mother and fetus. Pregnant women often represent an understudied population and there is often insufficient follow-up of the baby to truly define long-term risks.
Li J, Zhao H, Song JM, Zhang J, Tang YL, Xin CM. A meta-analysis of risk of pregnancy loss and caffeine and coffee consumption during pregnancy. Int J Gynaecol Obstet 2015;130(2):116–22. https://doi.org/10.1016/j.ijgo.2015.03.033. Important meta-analysis on the potential risk of caffeine to both the mother and fetus. Pregnant women often represent an understudied population and there is often insufficient follow-up of the baby to truly define long-term risks.
Administration USFDA. Spilling the beans: how much caffeine is too much? https://www.fda.gov/consumers/consumer-updates/spilling-beans-how-much-caffeine-too-much. Accessed 12/4/2022.
Canda Go. Caffeine in Foods. https://www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-additives/caffeine-foods.html. Accessed 12/16/2022.
Bernstein GA, Carroll ME, Dean NW, Crosby RD, Perwien AR, Benowitz NL. Caffeine withdrawal in normal school-age children. J Am Acad Child Adolesc Psychiatry 1998;37(8):858–65. https://doi.org/10.1097/00004583-199808000-00016. Important reference that explores the impact of caffeine in children and symptoms of withdrawal.
Wassef B, Kohansieh M, Makaryus AN. Effects of energy drinks on the cardiovascular system. World J Cardiol. 2017;9(11):796–806. https://doi.org/10.4330/wjc.v9.i11.796.
Rawson ES, Miles MP, Larson-Meyer DE. Dietary supplements for health, adaptation, and recovery in athletes. Int J Sport Nutr Exerc Metab. 2018;28(2):188–99. https://doi.org/10.1123/ijsnem.2017-0340.
Whirley BK, Einat H. Taurine trials in animal models offer no support for anxiolytic, antidepressant or stimulant effects. Isr J Psychiatry Relat Sci. 2008;45(1):11–8. https://www.ncbi.nlm.nih.gov/pubmed/18587165. Accessed 12/4/2022.
Kim W. Debunking the effects of taurine in Red Bull energy drink. Nutrition Bytes. 2003;9(1):1–8.
Zhang M, Izumi I, Kagamimori S, et al. Role of taurine supplementation to prevent exercise-induced oxidative stress in healthy young men. Amino Acids 2004;26(2):203–7. https://doi.org/10.1007/s00726-003-0002-3. Important references that explores the synergistic effects of taurine and caffeine which is critical in the investigation of products that often combined ingredients to improve performance.
Safety ECfHaF. Opinion on caffeine, taurine and D-glucurono - g -lactone as constituents of so-called “energy” drinks. https://ec.europa.eu/food/fs/sc/scf/out22_en.html. Accessed 12/4/2022.
Trautwein EA, Hayes KC. Plasma and whole blood taurine concentrations respond differently to taurine supplementation (humans) and depletion (cats). Z Ernahrungswiss. 1995;34(2):137–42. https://doi.org/10.1007/BF01636947.
Eley DW, Lake N, ter Keurs HE. Taurine depletion and excitation-contraction coupling in rat myocardium. Circ Res. 1994;74(6):1210–9. https://doi.org/10.1161/01.res.74.6.1210.
Yoon JA, Choi KS, Shin KO. General characteristics of taurine: a review. Korean J Food Nutr. 2015;28(3):404–14.
Williams MH. Dietary supplements and sports performance: introduction and vitamins. J Int Soc Sports Nutr. 2004;1(2):1–6. https://doi.org/10.1186/1550-2783-1-2-1.
Mayengbam S, Virtanen H, Hittel DS, et al. Metabolic consequences of discretionary fortified beverage consumption containing excessive vitamin B levels in adolescents. PLoS One. 2019;14(1):e0209913. https://doi.org/10.1371/journal.pone.0209913.
Antonelli-Ushirobira T, Yamaguti E, Uemura L, Nakamura C, Dias-Filho B, De Palazzo Mello J. Chemical and microbiological study of extract from seeds of Guaraná (Paullinia cupana var. sorbilis). Latin Am J Pharm. 2007;26(1):5–9.
Heckman MA, Weil J, de Gonzalez Mejia E. Caffeine (1, 3, 7-trimethylxanthine) in foods: a comprehensive review on consumption, functionality, safety, and regulatory matters. J Food Sci. 2010;75(3):R77-87. https://doi.org/10.1111/j.1750-3841.2010.01561.x.
Schimpl FC, da Silva JF, Goncalves JF, Mazzafera P. Guarana: revisiting a highly caffeinated plant from the Amazon. J Ethnopharmacol. 2013;150(1):14–31. https://doi.org/10.1016/j.jep.2013.08.023.
González-Vázquez M, Meza-Márquez OG, Gallardo-Velázquez T, Osorio-Revilla G, Velázquez Hernández JL, Hernández-Martínez M. Simultaneous determination of caffeine and taurine in energy drinks by FT-MIR spectroscopy coupled with multivariate analysis. J Spectrosc 2020;e8835846. https://www.hindawi.com/journals/jspec/2020/8835846/. Very important reference on the variance of actual concentrations of caffeine and taurine and energy drinks compared to the reported concentrations which if often significant.
Karlic H, Lohninger A. Supplementation of L-carnitine in athletes: does it make sense? Nutrition. 2004;20(7–8):709–15. https://doi.org/10.1016/j.nut.2004.04.003.
Bin-Jumah MN, Gilani SJ, Hosawi S, et al. Pathobiological relationship of excessive dietary intake of choline/L-carnitine: a TMAO precursor-associated aggravation in heart failure in sarcopenic patients. Nutrients. 2021;13(10):3453.
Weschler A, Aviram M, Levin M, Better OS, Brook JG. High dose of L-carnitine increases platelet aggregation and plasma triglyceride levels in uremic patients on hemodialysis. Nephron. 1984;38(2):120–4. https://doi.org/10.1159/000183292.
Koeth RA, Levison BS, Culley MK, et al. gamma-Butyrobetaine is a proatherogenic intermediate in gut microbial metabolism of L-carnitine to TMAO. Cell Metab. 2014;20(5):799–812. https://doi.org/10.1016/j.cmet.2014.10.006.
Ping FW, Keong CC, Bandyopadhyay A. Effects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment. Indian J Med Res. 2011;133(1):96–102. https://www.ncbi.nlm.nih.gov/pubmed/21321426. Accessed 12/4/2022.
Karmazyn M, Moey M, Gan XT. Therapeutic potential of ginseng in the management of cardiovascular disorders. Drugs. 2011;71(15):1989–2008. https://doi.org/10.2165/11594300-000000000-00000.
Zhang H, Hu C, Xue J, et al. Ginseng in vascular dysfunction: A review of therapeutic potentials and molecular mechanisms. Phytother Res. 2022;36(2):857–72. https://doi.org/10.1002/ptr.7369.
Vuksan V, Stavro MP, Sievenpiper JL, et al. Similar postprandial glycemic reductions with escalation of dose and administration time of American ginseng in type 2 diabetes. Diabetes Care. 2000;23(9):1221–6. https://doi.org/10.2337/diacare.23.9.1221.
Siegel RK. Ginseng abuse syndrome. Problems with the panacea. JAMA. 1979;241(15):1614–5. https://www.ncbi.nlm.nih.gov/pubmed/430716. Accessed 12/4/2022.
Ryu SJ, Chien YY. Ginseng-associated cerebral arteritis. Neurology. 1995;45(4):829–30. https://doi.org/10.1212/wnl.45.4.829.
Foster S. Top selling energy drink brands. https://www.caffeineinformer.com/the-15-top-energy-drink-brands. Accessed 12/4/2022.
Grasser EK, Dulloo AG, Montani JP. Cardiovascular and cerebrovascular effects in response to red bull consumption combined with mental stress. Am J Cardiol. 2015;115(2):183–9. https://doi.org/10.1016/j.amjcard.2014.10.017.
Bonati M, Latini R, Galletti F, Young JF, Tognoni G, Garattini S. Caffeine disposition after oral doses. Clin Pharmacol Ther. 1982;32(1):98–106. https://doi.org/10.1038/clpt.1982.132.
Nagajothi N, Khraisat A, Velazquez-Cecena JL, et al. Energy drink-related supraventricular tachycardia. Am J Med. 2008;121(4):e3-4. https://doi.org/10.1016/j.amjmed.2007.12.003.
Zhou A, Hypponen E. Long-term coffee consumption, caffeine metabolism genetics, and risk of cardiovascular disease: a prospective analysis of up to 347,077 individuals and 8368 cases. Am J Clin Nutr. 2019;109(3):509–16. https://doi.org/10.1093/ajcn/nqy297.
Mostofsky E, Rice MS, Levitan EB, Mittleman MA. Habitual coffee consumption and risk of heart failure: a dose-response meta-analysis. Circ Heart Fail. 2012;5(4):401–5. https://doi.org/10.1161/CIRCHEARTFAILURE.112.967299.
Groh CA, Faulkner M, Getabecha S, et al. Patient-reported triggers of paroxysmal atrial fibrillation. Heart Rhythm 2019;16(7):996–1002. https://doi.org/10.1016/j.hrthm.2019.01.027. Very important reference on the correlation of caffiene as a trigger of symptoms in patients with atrial fibrillation. Although the incidence of atrial fibrillation is not increased, symptoms with caffeine use are augmented.
Kim EJ, Hoffmann TJ, Nah G, Vittinghoff E, Delling F, Marcus GM. Coffee consumption and incident tachyarrhythmias: reported behavior, Mendelian randomization, and their interactions. JAMA Intern Med 2021;181(9):1185–1193. https://doi.org/10.1001/jamainternmed.2021.3616. Very important reference that shows that routine caffeine use with cofffee is not associated with a higher risk of atrial fibrilaltion in the community.
Chelsky LB, Cutler JE, Griffith K, Kron J, McClelland JH, McAnulty JH. Caffeine and ventricular arrhythmias. An electrophysiological approach. JAMA. 1990;264(17):2236–40. https://www.ncbi.nlm.nih.gov/pubmed/2214101. Accessed 12/4/2022. Very important reference that shows that caffeine use prior to an electrophyiology study does not increase the risk of inducible ventricualr arrhythmias.
Dixit S, Stein PK, Dewland TA, et al. Consumption of caffeinated products and cardiac ectopy. J Am Heart Assoc. 2016;5(1):e002503. https://doi.org/10.1161/JAHA.115.002503.
Marcus GM. Evaluation and management of premature ventricular complexes. Circulation. 2020;141(17):1404–18. https://doi.org/10.1161/CIRCULATIONAHA.119.042434.
Ali F, Rehman H, Babayan Z, Stapleton D, Joshi DD. Energy drinks and their adverse health effects: a systematic review of the current evidence. Postgrad Med. 2015;127(3):308–22. https://doi.org/10.1080/00325481.2015.1001712.
Azuma J, Sawamura A, Awata N. Usefulness of taurine in chronic congestive heart failure and its prospective application. Jpn Circ J. 1992;56(1):95–9. https://doi.org/10.1253/jcj.56.95.
Schaffer S, Kim HW. Effects and mechanisms of taurine as a therapeutic agent. Biomol Ther (Seoul). 2018;26(3):225–41. https://doi.org/10.4062/biomolther.2017.251.
Shimamoto K, Ando K, Fujita T, et al. The Japanese Society of Hypertension Guidelines for the Management of Hypertension (JSH 2014). Hypertens Res. 2014;37(4):253–390. https://doi.org/10.1038/hr.2014.20.
Huxtable R, Bressler R. Taurine concentrations in congestive heart failure. Science. 1974;184(4142):1187–8. https://doi.org/10.1126/science.184.4142.1187.
Katakawa M, Fukuda N, Tsunemi A, et al. Taurine and magnesium supplementation enhances the function of endothelial progenitor cells through antioxidation in healthy men and spontaneously hypertensive rats. Hypertens Res. 2016;39(12):848–56. https://doi.org/10.1038/hr.2016.86.
Sun Q, Wang B, Li Y, et al. Taurine supplementation lowers blood pressure and improves vascular function in prehypertension: randomized, double-blind, placebo-controlled study. Hypertension. 2016;67(3):541–9. https://doi.org/10.1161/HYPERTENSIONAHA.115.06624.
Baum M, Weiss M. The influence of a taurine containing drink on cardiac parameters before and after exercise measured by echocardiography. Amino Acids. 2001;20(1):75–82. https://doi.org/10.1007/s007260170067.
Benjo AM, Pineda AM, Nascimento FO, Zamora C, Lamas GA, Escolar E. Left main coronary artery acute thrombosis related to energy drink intake. Circulation 2012;125(11):1447–8. https://doi.org/10.1161/CIRCULATIONAHA.111.086017. Important study on the potential risk of energy drinks when consumed in combination with alcholol and other products..
Hayes KC, Pronczuk A, Addesa AE, Stephan ZF. Taurine modulates platelet aggregation in cats and humans. Am J Clin Nutr 1989;49(6):1211–6. https://doi.org/10.1093/ajcn/49.6.1211. Very important study on the risk of platelet aggregation with taurine supplementation. Platelet aggregation can increase risk of thrombosis in patients genetically predisposed or with vascular disease that increases risk.
Cui R, Iso H, Date C, Kikuchi S, Tamakoshi A, Japan Collaborative Cohort Study G. Dietary folate and vitamin b6 and B12 intake in relation to mortality from cardiovascular diseases: Japan collaborative cohort study. Stroke. 2010;41(6):1285–9. https://doi.org/10.1161/STROKEAHA.110.578906.
Bonaa KH, Njolstad I, Ueland PM, et al. Homocysteine lowering and cardiovascular events after acute myocardial infarction. N Engl J Med. 2006;354(15):1578–88. https://doi.org/10.1056/NEJMoa055227.
McCully KS, Ragsdale BD. Production of arteriosclerosis by homocysteinemia. Am J Pathol. 1970;61(1):1–11. https://www.ncbi.nlm.nih.gov/pubmed/5488869. Accessed 12/4/2022.
Kwon HM, Lee YS, Bae HJ, Kang DW. Homocysteine as a predictor of early neurological deterioration in acute ischemic stroke. Stroke. 2014;45(3):871–3. https://doi.org/10.1161/STROKEAHA.113.004099.
Cappelletti S, Piacentino D, Fineschi V, Frati P, Cipolloni L, Aromatario M. Caffeine-related deaths: manner of deaths and categories at risk. Nutrients. 2018;10(5):611. https://doi.org/10.3390/nu10050611.
Baghkhani L, Jafari M. Cardiovascular adverse reactions associated with Guarana: is there a causal effect? J Herb Pharmacother. 2002;2(1):57–61. https://www.ncbi.nlm.nih.gov/pubmed/15277107. Accessed 12/4/2022.
DiNicolantonio JJ, Lavie CJ, Fares H, Menezes AR, O’Keefe JH. L-Carnitine in the secondary prevention of cardiovascular disease: systematic review and meta-analysis. Mayo Clin Proc. 2013;88(6):544–51. https://doi.org/10.1016/j.mayocp.2013.02.007.
Iliceto S, Scrutinio D, Bruzzi P, et al. Effects of L-carnitine administration on left ventricular remodeling after acute anterior myocardial infarction: the L-Carnitine Ecocardiografia Digitalizzata Infarto Miocardico (CEDIM) Trial. J Am Coll Cardiol 1995;26(2):380–7. https://doi.org/10.1016/0735-1097(95)80010-e. Very important study on the role of L-carnitine and risk of heart failure and death after myocardial infarction. The doses of L-carnitine in energy drinks are much lower than those used in this study.
Zhu Y, Li Q, Jiang H. Gut microbiota in atherosclerosis: focus on trimethylamine N-oxide. APMIS. 2020;128(5):353–66. https://doi.org/10.1111/apm.13038.
Emonds JJ, Ringel C, Reinicke M, et al. Influence of trimethylamine N-oxide on platelet activation. Nutrients. 2022;14(16):3261. https://doi.org/10.3390/nu14163261.
Worthley MI, Prabhu A, De Sciscio P, Schultz C, Sanders P, Willoughby SR. Detrimental effects of energy drink consumption on platelet and endothelial function. Am J Med. 2010;123(2):184–7. https://doi.org/10.1016/j.amjmed.2009.09.013.
Torbey E, Abi Rafeh N, Khoueiry G, Kowalski M, Bekheit S. Ginseng: a potential cause of long QT. J Electrocardiol. 2011;44(3):357–8. https://doi.org/10.1016/j.jelectrocard.2010.08.007.
Winniford MD. Energy drinks: another cause of QT prolongation? J Am Heart Assoc. 2019;8(11):e012833. https://doi.org/10.1161/JAHA.119.012833.
Rottlaender D, Motloch LJ, Reda S, Larbig R, Hoppe UC. Cardiac arrest due to long QT syndrome associated with excessive consumption of energy drinks. Int J Cardiol. 2012;158(3):e51–2. https://doi.org/10.1016/j.ijcard.2011.10.017.
Steinke L, Lanfear DE, Dhanapal V, Kalus JS. Effect of “energy drink” consumption on hemodynamic and electrocardiographic parameters in healthy young adults. Ann Pharmacother. 2009;43(4):596–602. https://doi.org/10.1345/aph.1L614.
Seo E, Kim S, Lee SJ, Oh BC, Jun HS. Ginseng berry extract supplementation improves age-related decline of insulin signaling in mice. Nutrients. 2015;7(4):3038–53. https://doi.org/10.3390/nu7043038.
Seely D, Dugoua JJ, Perri D, Mills E, Koren G. Safety and efficacy of panax ginseng during pregnancy and lactation. Can J Clin Pharmacol. 2008;15(1):e87–94. https://www.ncbi.nlm.nih.gov/pubmed/18204104. Accessed 12/4/2022.
Nanthakumar K, Lau YR, Plumb VJ, Epstein AE, Kay GN. Electrophysiological findings in adolescents with atrial fibrillation who have structurally normal hearts. Circulation. 2004;110(2):117–23. https://doi.org/10.1161/01.CIR.0000134280.40573.D8.
Di Rocco JR, During A, Morelli PJ, Heyden M, Biancaniello TA. Atrial fibrillation in healthy adolescents after highly caffeinated beverage consumption: two case reports. J Med Case Rep. 2011;5:18. https://doi.org/10.1186/1752-1947-5-18.
Namdar M, Schepis T, Koepfli P, et al. Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls. PLoS One. 2009;4(5):e5665. https://doi.org/10.1371/journal.pone.0005665.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of Interest
The authors declare no competing interests.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Bunch, K.T., Peterson, M.B., Smith, M.B. et al. An Overview of the Risks of Contemporary Energy Drink Consumption and Their Active Ingredients on Cardiovascular Events. Curr Cardiovasc Risk Rep 17, 39–48 (2023). https://doi.org/10.1007/s12170-023-00716-3
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12170-023-00716-3