Just one energy drink could increase risk of heart disease, experts warn.

Here’s what happens to your body 30 minutes after a can of Rockstar.

The jury has been out on energy drinks for some time. The high amounts of caffeine in the drinks can be dangerous in large quantities, which is why health professionals – and these days the bottles and cans themselves – caution you should limit your intake to one or two drinks per day at most (a warning many people, especially young people, disregard).

But what else do energy drinks do to your body? To find out, researchers from the Mayo Clinic looked at the effects of consuming just one 480 ml (16 oz) energy drink, and their conclusion was alarming: the recorded increase in blood pressure and stress hormone responses were so significant that they could conceivably trigger new cardiovascular events.

“Energy drink consumption has been associated with serious cardiovascular events, possibly related to caffeine and other stimulants,” the researchers write. “We hypothesised that drinking a commercially available energy drink compared with a placebo drink increases blood pressure and heart rate in healthy adults at rest and in response to mental and physical stress… which could predispose to increased cardiovascular risk.”

To test their theory, the researchers gave 25 healthy volunteers aged 18 years or older a 480 ml can of Rockstar (pictured above) and instructed them to drink it within five minutes. The group had fasted beforehand and also abstained from alcohol and caffeine for 24 hours prior to the experiment.

On another testing day two weeks removed (in a random order), the same participants drank a placebo beverage designed to resemble the energy drink in taste, texture and colour – but lacking any of the caffeine or other stimulants found in the Rockstar drink, which includes 240 mg of caffeine, 2000 mg of taurine, and extracts of guarana seed, ginseng root, and milk thistle. Gotta love that milk thistle!

What the researchers found when they compared the results of the two drinking sessions was that consumption of the energy drink saw a 6.4 percent increase in average blood pressure.

Further, the average norepinephrine level – the hormone responsible for mobilising the body into action, especially with regards to the fight-or-flight response – increased from 150 picograms per millilitre to 250 pg/mL in those who consumed the energy drink, whereas the placebo elicited only a 140 pg/mL to 179 pg/mL increase (a 74 percent vs 31 percent change, as the researchers point out).

The authors concede that their study is small and is limited to measuring the effects of just one serve of an energy drink, saying more study is needed to measure how harmful these acute changes in stress hormone responses could be in the bigger picture. Nonetheless, the results they’ve already seen may be of concern – especially to those who consume energy drinks in large amounts.

“These acute hemodynamic and adrenergic changes may predispose to increased cardiovascular risk,” the authors write. “Further research in larger studies is needed to assess whether the observed acute changes are likely to increase cardiovascular risk.”

Why Vodka Red Bulls Are Bad News: Teens Drink More When Mixing Alcohol And Energy Drinks

Ostensibly, a vodka Red Bull seems like the end-all be-all of hard partying cocktails. You’ve got the energy drink that assures you won’t be the first of your friends to call it a night combined with the inhibition-lowering effects of alcohol. What could go wrong? From a health perspective, a lot.

Red Bull

A study conducted at Dartmouth’s Norris Cotton Cancer Center has found that American teenagers between the ages of 15 and 17 who have ever mixed energy drinks and alcohol are four times more likely to develop an alcohol use disorder compared to teens who have never experimented with this combination.

“These findings are concerning,” first author of the study Dr. Jennifer A. Emond said in astatement. “They highlight that mixed use of alcohol and energy drinks may signal the development of abusive drinking behaviors among adolescents.”

Emond and her colleagues used a sample of over 3,000 adolescents and young adults between the ages of 15 and 23 from across the United States. While a growing number of studies have focused on the negative outcomes of combining energy drinks and alcohol, these analyses have generally focused on undergraduate college students and rarely include high school students.

Out of 3,342 study participants, 9.7 percent of adolescents between the ages of 15 and 17 reported consuming an energy drink combined with alcohol. Adolescents who reported mixing energy drinks and alcohol not only increased their risk for binge drinking but were also four times more likely to meet the criteria for alcohol use disorder.

“Abusive alcohol use among adolescents is a dangerous behavior that can lead to injury, chronic alcohol use and abuse, and even death,” Emond added. “Identifying those most at risk for alcohol use is critical. Given that this is a sensitive issue, it’s possible that clinicians, parents, and educators might open dialogues about alcohol use with adolescents by starting the discussion on the topic of energy drinks.”

A similar study conducted by researchers from Australia found that the combination of energy drinks and alcohol increased a person’s desire to keep drinking. People under the age of 30 who consumed 60ml of vodka with a Red Bull Silver Edition energy drink had a stronger desire to continue drinking alcohol compared to people who consumed 60ml of vodka with club soda.

Clearly, the desire to drink more alcohol was accompanied by “a cycle of greater intoxication,” namely binge drinking. Other hazardous behaviors that can result from a greater urge to drink include drunk driving, risky sexual behavior, and alcohol-related violence.

Energy drinks ‘change heartbeat’

Caffeine energy drinks ‘intensify heart contractions’

Energy drinks

Energy drinks packed with caffeine can change the way the heart beats, researchers warn.

The team from the University of Bonn in Germany imaged the hearts of 17 people an hour after they had an energy drink.

The study showed contractions were more forceful after the drink.

The team told the annual meeting of the Radiological Society of North America that children and people with some health conditions should avoid the drinks.

Researcher Dr Jonas Dorner said: “Until now, we haven’t known exactly what effect these energy drinks have on the function of the heart.

“The amount of caffeine is up to three times higher than in other caffeinated beverages like coffee or cola.

“There are many side effects known to be associated with a high intake of caffeine, including rapid heart rate, palpitations, rise in blood pressure and, in the most severe cases, seizures or sudden death.”

The researchers gave the participants a drink containing 32mg per 100ml of caffeine and 400mg per 100ml of another chemical, taurine.

Short-term impact

They showed the chamber of the heart that pumps blood around the body, the left ventricle, was contracting harder an hour after the energy drink was taken than at the start of the study.

Dr Dorner added: “We’ve shown that energy drink consumption has a short-term impact on cardiac contractility.

“We don’t know exactly how or if this greater contractility of the heart impacts daily activities or athletic performance.”

The impact on people with heart disease is also unknown.

However, the research team advises that children and people with an irregular heartbeat should avoid the drinks.

The British Soft Drinks Association already says the drinks are not for children.

Too Much Caffeine Can Slow Brain Development.

Offduty: Caffine Drinks

These days, caffeine is the most commonly consumed psychoactive drug. It is estimated that at least 50% of adults consume caffeine on a daily basis. It is also estimated that soda and sweetened drinks are the single most consumed food in the American diet. The energy drink sales market in the United States throughout 2009 brought in roughly $4 billion dollars, with Red Bull coming in as the top selling energy drink, with Monster and Rockstar coming in 2nd and 3rd place. Red Bull currently has a 65 percent share of the U.S. Energy drink market. And in 2012 it took in sales of over $1 billion dollars alone. Coca-cola earned an impressive $4.68 billion in 2012. Alarmingly, more than one-third of teens are consuming are energy drinks daily “just to get through the day.”

“The soda fountain is the most valuable, most useful, most profitable, and altogether most beneficial business building feature assimilated by the drugstore in a generation…” – John Somerset, Drug Topics June 1920


When we feel tired or drowsy, this is thanks to the binding of adenosine to adenosine-receptors on the synapses of neurons in our brain. These receptors help to facilitate a “slow-down” of our brain’s signaling functions, and induces a tired sensation, when adenosine is bound. Caffeine’s chemical structure is vastly similar to that of adenosine, and the neurons in our brain will allow for either caffeine or adenosine to bind to the adenosine-receptors, effectively blocking adenosine’s binding. When we are really active, and expend adenosine triphosphate (ATP) (often referred to as the ‘molecular unit of currency’ or ‘energy currency’), there are higher levels of adenosine concentration in our brain. (Fisone, Borgkvist,& Usiello, 2004).

Caffeine is an antagonist which inhibits the effects of adenosine and competes for binding sites. When caffeine occupies the binding sites on nerve cells, it doesn’t mimic the ‘slow-down’ that is initiated when adenosine binds to the site. Instead of slowing down, the cells speed up and fire rapidly. Consuming too much caffeine can have many negative effects on our health, common symptoms of caffeine withdrawal include (but are not limited to): headaches, fatigue, drowsiness, nausea, muscle pains, and stiffness. It can also have negative effects on our sleep, even our brain development.

Humans particularly need sleep during puberty, as during this time their brain matures at a faster rate. Scientists exploring the effects of caffeine on rats found the maturing process in the rodents’ brains were inhibited and ultimately delayed due to caffeine consumption. Researchers at the University Children’s Hospital Zurich, found that in pubescent rats, caffeine intake equating to three to four cups of coffee per day in humans resulted in reduced deep sleep and delayed brain development. Compared to the rats that had been given pure drinking water, the researchers found that the ones which had consumed the water had far more neural connections in the brain than the caffeine-drinking animals.


Along with the growing controversy surrounding caffeinated drinks, last year Mayor Michael Bloomberg sought to ban large soda drinks in New York, in an effort to battle current rates of consumption. But we all know how well prohibition works, and the effort has received harsh criticism from fellow Americans. Instead of buying one really large “forbidden” size drink, what is stopping people from purchasing several? The legislation clearly isn’t going to be as effective as originally intended. If someone wants to drink 16oz of soda, they are going to find a way to drink it.

Excessive caffeine consumption obviously negatively impacts our overall health. Sugar in these soft drinks can lead to high insulin levels, which would contribute to high blood pressure, high cholesterol, heart disease, diabetes, and also weight gain. The acid in the soda also eats away at tooth enamel, weakening your teeth. The aspartame sugar substitute in diet soda (and even some non-diet sodas) also isn’t very beneficial for the body, consumption of which can produce brain tumors, birth defects, diabetes, emotional disorders, and epilepsy/seizures. Everything should be consumed in moderation, and where there are withdrawal effects there is also addiction and dependence in a physiological as well as psychological manner.

Use of caffeinated substances and risk of crashes in long distance drivers of commercial vehicles.

caffeinecrystalsObjective To determine whether there is an association between use of substances that contain caffeine and the risk of crash in long distance commercial vehicle drivers.

Design Case-control study.

Setting New South Wales (NSW) and Western Australia (WA), Australia.

Participants 530 long distance drivers of commercial vehicles who were recently involved in a crash attended by police (cases) and 517 control drivers who had not had a crash while driving a commercial vehicle in the past 12 months.

Main outcome measure The likelihood of a crash associated with the use of substances containing caffeine after adjustment for factors including age, health disorders, sleep patterns, and symptoms of sleep disorders as well as exposures such as kilometres driven, hours slept, breaks taken, and night driving schedules.

Results Forty three percent of drivers reported consuming substances containing caffeine, such as tea, coffee, caffeine tablets, or energy drinks for the express purpose of staying awake. Only 3% reported using illegal stimulants such as amphetamine (“speed”); 3,4 methylenedioxymethamphetamine (ecstasy); and cocaine. After adjustment for potential confounders, drivers who consumed caffeinated substances for this purpose had a 63% reduced likelihood of crashing (odds ratio 0.37, 95% confidence interval 0.27 to 0.50) compared with drivers who did not take caffeinated substances.

Conclusions Caffeinated substances are associated with a reduced risk of crashing for long distance commercial motor vehicle drivers. While comprehensive mandated strategies for fatigue management remain a priority, the use of caffeinated substances could be a useful adjunct strategy in the maintenance of alertness while driving.