Energy drinks are popular, and with exciting names like Red Bull, Adrenaline Rush, 5-Hour Energy, and Hype, they offer the promise of an energy boost and greater alertness. These beverages are a huge business and they are directly targeted to teens and young adults, particularly males. But are they safe? And are they safe to use in tandem with exercise and competitive sports, particularly in teenage athletes?
What's in an energy drink?
Energy drinks are soft drink-like beverages that contain caffeine in combination with other ingredients such as taurine, guarana, and B vitamins, and that claim to provide extra energy.
Caffeine
Caffeine in the form of coffee is a stimulant used by people all over the world. Because of the widespread use of coffee, it is easy to forget that caffeine itself is a drug, and not without side effects. Adverse effects of too much caffeine may include nervousness, irritability, sleeplessness, increased urination, abnormal heart rhythms (arrhythmia), and stomach upset.
Some energy drinks do not list caffeine as an ingredient or state the amount of caffeine on the label. Instead, they may label their drinks as containing guarana or yerba mate, substances that naturally have as much as 40mg of caffeine per gram. Energy drinks can contain between 75–150mg of caffeine per serving. However, each container may hold 1–3 servings, which can result in some drinks having over 450mg of caffeine per bottle. In comparison, one serving (8 fl oz/235ml) of coffee, tea, or cola contains between 134–240 mg, 48–175 mg, and 22–46 mg of caffeine, respectively.
The amount of caffeine in a single energy drink is probably not harmful for most adults. A recent literature review determined that consumption of ≤ 400 mg of caffeine daily by healthy adults is not associated with adverse effects. However, more than one bottle of an energy drink in combination with other caffeinated beverages can easily increase a person’s caffeine intake to unhealthy levels. Also, the levels of caffeine in energy drinks often exceed the safe recommendations for teens. The American Academy of Pediatrics suggests adolescents should limit caffeine consumption to less than 100 mg daily.
Taurine
Taurine is an amino acid that the body is able to produce naturally. It is also found naturally in protein-containing foods such as meat and dairy products. Some energy drinks claim that taurine makes you more alert, lowers the risk of diabetes, and can treat high blood pressure. These claims are largely unproven. Many energy drinks contain as much as 1,000 mg of taurine per 8-oz (225-ml) serving; and the long-term safety of such large doses is not known.
B Vitamins
B vitamins include thiamin (B1), riboflavin (B2), niacin, folate, pyridoxine (B6), pantothenic acid, cyanocobalamin (B12), and biotin. B vitamins are an important part of a healthy diet and are essential for the metabolism of carbohydrates, protein, and fat. However, some energy drinks contain as much as 2000%–8000% of the Daily Value for some B vitamins. While most of this excess is lost in the urine, pyridoxine (B6) may cause nerve damage when habitually consumed at very high doses. Also, high levels of folate can mask a cyanocobalamin (B12) deficiency. Therefore, it is best not to consume extremely high levels of B vitamins.
The bottom line is that there is no evidence that high intakes of B vitamins improve athletic performance. The fact is, most people consume more than their daily B vitamin requirement in their normal diet.
Herbs
Many energy drinks contain herbs, such as gingko biloba, ginseng, and others. These popular herbs boast many health benefits; however, there is very little scientific evidence to support their use. Ginseng, for example, is touted as a way to speed recovery from illness; improve mental and physical performance; control blood glucose; and lower blood pressure. However, there is no scientific evidence to support any of these assertions. Most of these herbs have not been shown to improve athletic performance or sharpen focus. And although the level of herbs added to most energy drinks is low, these substances can cause adverse interactions with some medications.
Glucuronlactone
Glucuronlactone is an ingredient found in some energy drinks, with the claim that it detoxifies the body and protects against cancer! Needless to say, there is no scientific evidence to support these claims.
Energy drinks versus sports drinks
Energy drinks and sports drinks are quite different:
- Energy drinks are soft drinks with high levels of sugar, caffeine, taurine, ginseng and/or B vitamins.They are marketed for their stimulant effects and they are largely untested, especially in athletes. And they are also unregulated.
- Sports drinks, on the other hand, generally contain from 6%–8% carbohydrate, plus electrolytes like sodium. These drinks are designed to fuel working muscles and maintain optimal hydration as a means of boosting athletic performance. Sports drinks have been extensively studied and have been shown to be safe and effective for athletes.
Energy drinks and sports
Many athletes use caffeine before and during competitions to help boost performance. Energy drinks are heavily marketed toward young men as performance enhancers, with ads and promotions suggesting a benefit for endurance athletics and extreme sports. Many of these drinks claim the ability to increase endurance, reaction time, and concentration due to exotic herbs and other ingredients; but in reality, any physical or mental effects most likely come from caffeine!
Research has found that consumption of moderate levels of caffeine prior to and during heavy exercise can be safe and effective. But the safety or efficacy of consuming caffeine in combination with the herbal ingredients found in many energy drinks, particularly prior to or during exercise, has yet to be established. Also, the amount of caffeine tested in much of the scientific research is far lower than that found in many energy drinks: Very high levels of caffeine intake greatly increase the risks of negative side effects, with little evidence for any added athletic benefit.
Moderate caffeine intake does not have a negative impact on hydration and performance. However, the effects on hydration of much larger quantities of caffeine found in energy drinks are not known. Also, the high concentration of glucose in many energy drinks results in slower absorption of fluids from the gut, and may lead to gastrointestinal distress and dehydration. Sports drinks are specially formulated to contain the appropriate balance of glucose and electrolytes for easy absorption, thereby providing fuel to working muscles, as well as water and electrolytes to maintain optimal hydration. Most energy drinks have not been designed this way, and statements from certain energy drinks companies state that their product is "not a fluid replacement drink."*
Although low levels of caffeine do not seem to have a large effect on hydration and electrolyte balance during exercise
14, the high level of sugar in many energy drinks may have a negative impact. The high concentration of glucose in many energy drinks results in slower absorption of fluids in the gut, and may lead to gastrointestinal distress and dehydration
15. Sports drinks are specially formulated to contain the appropriate balance of glucose and electrolytes for easy absorption, thereby providing fuel to working muscles, as well as water and electrolytes to maintain optimal hydration. Most energy drinks have not been designed this way, and statements from certain energy drinks companies claim that their product is "not a fluid replacement drink."
The bottom line is that there are still many unknowns when it comes to energy drinks and athletics. Therefore, the consumption of energy drinks prior to and during exercise is not recommended.
Why energy drinks and sports are not a good mix
- Not regulated by government regulatory bodies
- Highly variable levels of caffeine depending on the drink and brand
- The effect of high levels of caffeine found in energy drinks does not result in greater athletic benefits
- Caffeine levels that may result in side effects
- Potentially dangerous levels of B vitamins
- Various ingredients with minimal scientific evidence to support their safety and use
- Not designed as a fluid replacement beverage; may even delay glucose absorption and result in dehydration
- Not designed to replenish electrolytes lost in sweat
- There are many unknowns related to energy drink consumption and their effect on athletic performance
References:
1. The European Commission on Food Safety. Opinion on Caffeine, Taurine and D-Glucurono- g -Lactone as constituents of so-called "energy" drinks. 1999.
2. USA Today http://www.usatoday.com/news/health/2008-10-21-energy-drinks_N.htm. Accessed 10/22/2008
3. Finnegan D. The health effects of stimulant drinks. Nutrition Bulletin 2003; 28:147–155.
4. Nawrot P, Jordan S, Eastwood J, Rotstein J, Hugenholtz A, Feeley M. Effects of caffeine on human health. Food Addit Contam 2003; 20:1–30.
5. American Academy of Pediatrics www.aap.org accessed 10/28/2008
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9. The European Commission on Food Safety. Opinion on Caffeine, Taurine and D-Glucurono- g -Lactone as constituents of so-called "energy" drinks. 1999.
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15. Jeukendrup AE, Jentjens R. Oxidation of carbohydrate feedings during prolonged exercise: current thoughts, guidelines and directions for future research. Sports Med. 2000 Jun; 29(6):407–24.
16. Reissig CJ, Strain EC, Griffiths RR. Drug Alcohol Depend. 2008 Sep 20. [Epub ahead of print]
17. Kavita M. Babu, MD, Richard James Church, MD, William Lewander, MD. “Energy Drinks: The New Eye-Opener For Adolescents”. Clinical Pediatric Emergency Medicine. 2008
18. Clauson KA, et al. Safety issues associated with commercially available energy drinks. J Am Pharm Assoc (2003). 2008 May-Jun; 48(3):e55–63; quiz e64–7.
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20. Brass EP. Supplemental carnitine and exercise. Am J Clin Nutr. 2000 Aug;72(2 Suppl):618S–23S.
References:
1. The European Commission on Food Safety. Opinion on Caffeine, Taurine and D-Glucurono- g -Lactone as constituents of
so-called "energy" drinks. 1999.
2. USA Today http://www.usatoday.com/news/health/2008-10-21-energy-drinks_N.htm. Accessed 10/22/2008
3. Finnegan D. The health effects of stimulant drinks. Nutrition Bulletin 2003;28:147–155.
4. Nawrot P, Jordan S, Eastwood J, Rotstein J, Hugenholtz A, Feeley M. Effects of caffeine on human health. Food Addit Contam 2003;2
Topics:
General, Pre-Workout, Post-Workout, Hydration
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