I'm going to try something a little different for this video. What I've done is cut and
pasted sections from two recent reviews of energy drinks, with some modifications to
improve clarity. It's going to be a bit dry, but should answer some very common questions
about safety and evidence of effectiveness. Both papers are available as free full text
if you want to do your own research. Link in the underbar.
Energy drinks are increasingly popular among a young and male crowd, marketed as enhancing
focus, performance at athletic or intellectual tasks, but also sometimes marketed as club
drinks, edgy recreational drugs and party aids. Long-term exposure to the various components
of Energy Drinks may result in significant alterations in the cardiovascular system,
and the safety of Energy Drinks has not been fully established. We will attempt to answer
the simple question: “Is it safe for me to drink an energy beverage?”
Red Bull was introduced in Austria in 1987 and in the United States in 1997. Since then,
the energy beverage market has grown exponentially. Hundreds of different brands are now marketed,
with caffeine content ranging from a modest 50 mg to an alarming 505 mg per can or bottle,
equivalent to five cups of coffee. In the United States, Red Bull enjoyed a 65% share
of the $650-million energy drink market in 2005, and its sales are growing at about 35%
per year. The United States is the world's largest consumer of Energy drinks by volume,
roughly 290 million gallons in 2007, or 3.8 qt per person per year. Consumption of energy
drinks is most common among those aged 11 to 35 years, and 24% to 57% of this age group
reported that they drank an energy drink within the past few months.
Recent studies have shown energy drink consumption to be positively associated with high-risk
behavior, including marijuana use, sexual risk taking, fighting, failure to use seat
belts, and taking risks on a dare, as well as with smoking, drinking, problems stemming
from alcohol abuse, and illicit drug use.
Clinical evidence demonstrates the behavioral stimulant effect of caffeine. It seems quite
likely that caffeine enhances human performance on some types of tasks (for example, maintaining
vigilance), especially among people who are not already adapted to caffeine. Among high-dose
habitual consumers, performance enhancements above and beyond reversing withdrawal are
likely to be modest at best.
The potential adverse effects of caffeine use, when not mixed with alcohol, are termed
caffeine intoxication.
Common features of caffeine intoxication include nervousness, anxiety, restlessness, insomnia,
gastrointestinal upset, tremors, tachycardia, psychomotor agitation and in very rare cases,
death. In addition to caffeine intoxication, the consumption of energy drinks has been
linked to seizures (Iyadurai and Chung, 2007), acute mania (Machado-Vieira et al., 2001),
and stroke (Worrall et al., 2005). Deaths attributed to energy drink consumption have
been reported in Australia, Ireland and Sweden (Ari Kapner, 2004). Considerable debate has
ensued as to whether these fatalities were a direct result of energy drink consumption.
There is an association between the heavy use of caffeine and the heavy use of alcohol
, and the ingestion of energy drinks in combination with alcohol is becoming increasingly popular
, with 24% of a large stratified sample of college students reporting such consumption
within the past 30 days. In a survey of 496 college students, 27% reported mixing alcohol
and energy drinks in the past month. Of those that mixed energy drinks and alcohol, 49%
used more than three energy drinks per occasion when doing so . In a survey of 1,253 college
students, energy drink users were disproportionately male and consumed alcohol more frequently
than non-energy drink users.
One study showed that ingestion of a caffeinated energy drink (Red Bull) with vodka reduced
participants perception of impairment of motor coordination in comparison to vodka alone,
but did not significantly reduce objective measures of alcohol-induced impairment of
motor coordination, reaction time, or breath alcohol concentration. Thus, when mixing energy
drinks and alcohol, users may not feel the symptoms of alcohol intoxication. This may
increase the potential for alcohol-related injury. Indeed, a recent survey of college
students found that in comparison to those who consumed alcohol alone, students who consumed
alcohol mixed with energy drinks had a significantly higher prevalence of alcohol-related consequences
including: being taken advantage of, or taking advantage of another student sexually, riding
in an automobile with a driver under the influence of alcohol, or being hurt or injured.
Studies in adult twins show that lifetime caffeine intake, caffeine toxicity and caffeine
dependence are significantly and positively associated with various psychiatric disorders
including major depression, generalized anxiety disorder, panic disorder, antisocial personality
disorder, alcohol dependence, and cannabis and cocaine abuse/dependence.
More specifically, with regard to cigarette smoking, human and animal studies show that
caffeine increases the reinforcing effects of nicotine. Epidemiology studies show that
cigarette smokers consume more caffeine than nonsmokers, an effect that may be partially
due to increased caffeine metabolism among cigarette smokers.
With regards to the other components of energy drinks like Red Bull, none of them appear
to be present at levels that would produce either a positive or negative effect.
Taurine, for example, which is a sulfur-containing amino acid, does have an effect on metabolism,
but the amount present even in several Red Bulls is still significantly below the level
that has any measurable effect. The amounts of guarana, taurine, and ginseng found in
popular energy drinks are also far below the amounts expected to deliver either therapeutic
benefits or adverse events. However, both caffeine and sugar are present in amounts
known to cause a variety of adverse health effects.
The amount of sugar provided in one can (or 500 mL) of an energy drink is typically about
54 g. A teaspoon of sugar weighs about 4 g, so a typical energy drink contains about 13
teaspoons, or just more than ¼ cup, of sugar.
Long-term exposure of the body to excesses of simple sugars is associated with the development
of obesity and insulin resistance. Pancreatic beta cells increase insulin secretion in response
to this reduction in insulin sensitivity. Over time, in many individuals, the beta cells
become unable to secrete sufficient insulin to maintain normal blood glucose levels, leading
to the development of diabetes.
In conclusion, one can of an energy drink during one session is safe for most healthy
individuals. However, excess consumption and consumption with other caffeine-containing
beverages or alcohol may lead to adverse effects and possibly death. Patients with clinically
relevant underlying medical conditions, including heart disease and hypertension, should consult
with their physician before drinking any energy drinks.