For nearly 40 years, Red Bull’s energy drinks have featured stick figures in their advertising—except in the United States. In 2014, a disgruntled customer sued the Austrian beverage manufacturer, claiming: “That’s not true at all.” However, the market has since grown richer and more diverse, with brands like Monster and 28 Black emerging. They convey the message: “Look here. With us, you’ll be more awake, more athletic, and incredibly cool.”
This is very popular among children and teenagers. Most consume their first can of energy drink before their 13th birthday. One in three teenagers aged 14 and older regularly drinks these sweet beverages. When asked why they drink such sweet beverages, they say they want mental highs and physical energy boosts.
What effect does taurine have?
Consumer advocates and parents alike view energy drinks very critically due to their high sugar and caffeine content. The dangerous effects of excessive caffeine on the cardiovascular system of people of all ages are well-documented and range from restlessness and irritability to rapid heartbeat, muscle tremors, panic attacks, and cardiac arrhythmias. However, research on the long-term consequences of regular energy drink consumption, especially on the developing brains of young people, is only now beginning. Besides caffeine, these drinks contain other ingredients, including sugar, flavorings, colorings, vitamins, antioxidants, and taurine. What do we know about this unusual substance?
Taurine, which is chemically known as 2‑aminoethanesulfonic acid, was first isolated in 1827 from the bile of a bull—specifically, a male domestic bovine (Bos taurus). It is also found in significant quantities in the brains, hearts, eyes, and muscles of mammals. Unlike cats, healthy humans can produce substantial amounts of this substance themselves. This enzymatic conversion primarily occurs in the liver. For this process, the body utilizes the sulfur-containing amino acids methionine and cysteine, which are found in proteins. Additionally, taurine can be obtained directly from animal-based foods such as fish, meat, eggs, and dairy products.
Newborns produce very little taurine
Newborns produce only minimal amounts of taurine because the enzymes in their livers are not yet fully active. Newborns receive taurine through breast milk or infant formula. In the United States, taurine has been added to formula as standard practice since the 1980s. While the European Food Safety Authority (EFSA) permits this addition, it does not explicitly recommend it. The EFSA bases its maximum permissible concentration on the average taurine content of breast milk, which is 7.8 milligrams per 100 milliliters.
Taurine plays a role in many physiological functions in humans and other mammals, and it is found virtually everywhere in the body. It plays a significant role in the growth and maturation of nerve cells, particularly during fetal development. As early as the 1980s, researchers observed the effects of taurine deficiency in cat mothers on their offspring. The kittens were born stillborn or underdeveloped, died more frequently after birth than well-nourished kittens, and exhibited brain damage. Therefore, it is logical to supplement taurine, especially for premature infants. However, due to the limited available data, it is unclear whether supplementation is beneficial.
Is taurine a therapeutic all-rounder?
It is well-established that taurine has antioxidant and anti-inflammatory properties. Furthermore, taurine is said to support heart health, prevent fatty liver disease, and protect nerve cells from damage, such as that caused by diabetes. Considerations for the therapeutic use of taurine are diverse and sometimes encouraging. However, the neuroprotective hypothesis is based on studies using animal models of neurodegenerative diseases, such as Alzheimer’s-prone transgenic mice. Therefore, its validity is controversial.
As long as they are healthy and eat a normal diet, older children, adolescents, and adults are unlikely to be deficient in taurine. However, despite the body’s need for this substance, questions arise about how much is needed and whether excessive taurine consumption, especially when combined with caffeine, could have negative effects.
Does taurine give you the strength of an ox?
Why is the amino acid derivative taurine added to energy drinks? The US company Monster Beverage, for example, writes on its website that taurine “can increase physical endurance.” The company cites a 2017 study as alleged proof. A team from Pakistan injected taurine into the abdominal cavities of twelve rats for a week. According to the publication, the rats subsequently demonstrated significantly greater muscle strength and improved memory in a maze. However, it is scientifically highly questionable to conclude that taurine can make athletes more efficient based on this study.
In a 2021 meta-analysis, Jennifer Kurtz and her team at Georgia State University evaluated 19 human studies. Roughly two-thirds of the studies reported positive effects on athletic performance. However, the researchers remain skeptical because the inconsistent and limited findings do not allow for a conclusive assessment.
Energy drinks contain too much caffeine for teenagers
However, the effect of caffeine on alertness and concentration is undisputed. For example, Red Bull contains the maximum legal amount of caffeine, 32 milligrams per 100 milliliters. In terms of caffeine content, a 10-ounce can is roughly equivalent to a cup of coffee. The standard can of Monster Energy — the market leader in Europe — contains 500 milliliters. With the same caffeine content, this is equivalent to about two cups of coffee. Two to three cups of coffee a day are considered safe for adults. However, children and teenagers react much more strongly to caffeine than adults who have been drinking coffee for years.
According to the European Food Safety Authority, adults should not consume more than three milligrams of caffeine per kilogram of body weight in a single dose. For a 50-kilogram adolescent, this limit is exceeded by a single 0.5‑liter can of Monster Energy. A study by the Robert Koch Institute found that one in four energy drink consumers between the ages of 12 and 17 regularly consumes more caffeine than is considered healthy.
How do taurine and caffeine affect the adolescent brain?
To this day, the way the developing body reacts to the combination of caffeine and taurine is not fully understood. Thomas Lücke, head of the Department of Pediatrics and Adolescent Medicine at the University Hospital of Bochum, explains what happens in the brain when we consume energy drinks. Both caffeine and taurine cross the blood-brain barrier, meaning they pass unhindered from the bloodstream to nerve cells. There, caffeine binds to and blocks adenosine receptors. “This counteracts the calming effect of the neurotransmitter adenosine.” Adenosine inhibits the release of the stimulating neurotransmitters glutamate and dopamine. Therefore, caffeine acts like a psychostimulant.
Taurine, on the other hand, has a GABAergic effect. This means that it acts like the calming neurotransmitter GABA (gamma-aminobutyric acid) and, thus, as an antagonist to the excitatory neurotransmitter glutamate. Overall, energy drinks have a stimulating effect, with caffeine’s effect being predominant. “It’s like I’m going full throttle while simultaneously using the handbrake,” says Lücke, adding, “That’s not good.”
This is especially true for an organ that continues to mature well into young adulthood. In fact, the brain isn’t considered fully developed until around age 25. The period around puberty is also a critical phase during which neural networks are rewired. Lücke believes that if young people only consumed energy drinks occasionally, the amount of caffeine and taurine ingested would be “safe.” However, it often doesn’t stop at the occasional can.
Consuming energy drinks with alcoholic beverages is truly dangerous. According to Cecile Marczinski, a psychology professor at Northern Kentucky University, energy drinks amplify the rewarding effects of alcohol. The caffeine also likely masks the unpleasant warning signs of impending intoxication. Furthermore, taurine inhibits cytochrome P450 2E1, the enzyme the body uses to break down alcohol. For pediatric neurologist Lücke, the combination of energy drinks and spirits is a nightmare scenario because it introduces another clearly neurotoxic substance.
The high sugar content may also contribute to the euphoric feeling. A standard 12-ounce can of Red Bull contains 37 grams of sugar, equivalent to more than twelve sugar cubes, and nearly 150 kilocalories. Thus, a single Red Bull provides a teenager with significantly more than the WHO’s recommended daily maximum for free sugars. The sugar masks the bitter taste of caffeine, which is why the cold drink is often gulped down faster than coffee. Sugar-free versions containing the controversial sweeteners aspartame, acesulfame, and sucralose have the same effect.
After consuming energy drinks, they ended up in the emergency room
Several reviews have documented the harmful effects of energy drinks on the cardiovascular and nervous systems of adolescents. For instance, U.S. experts analyzed data from poison control centers nationwide. Between 2010 and 2013, 10,588 cases related to energy drinks were reported. This included both adolescents who knowingly consumed the beverages and children who unintentionally poisoned themselves with energy drinks. The youngest patients were under five years old. Many affected individuals required emergency room treatment for neurological and cardiovascular problems, and 14 cases were considered life-threatening. Tragically, one girl died.
What about brain development? As expected, there are no controlled studies in which children were exposed to the effects of energy drinks over an extended period. Most findings on the direct effects of caffeine and taurine on the developing nervous system come from animal studies or experiments with cell cultures.
