Concerns about energy drinks have existed almost as long as the beverages themselves, but the recent news of five deaths possibly related to Monster Energy drinks has reignited worries.
While caffeine is cited as a key ingredient in the death investigations, it's caffeine in combination with other ingredients that make energy drinks such as Monster troublesome, says John P. Higgins M.D., associate professor of medicine at the University of Texas Health Science Center at Houston. These ingredients include taurine, glucuronolactone, B vitamins, guarana, ginseng, ginkgo biloba, l-carnitine, sugars, antioxidants, and trace minerals.
"It is likely that there are effects due to the interaction of substances in energy beverages which have had little research done on them and are not well understood," he says. "In addition, most energy beverages also contain guarana, which contains high levels of caffeine, thus adding to the caffeine already present."
Excessive consumption of caffeine may cause caffeine intoxication, resulting in rapid heart rate, vomiting, hypokalemia (low potassium in the blood), cardiac arrest, seizures, and, yes, untimely death. A 24-ounce can of Monster contains 240 milligrams of caffeine, while the same amount of cola that has 70 to 80 milligrams. Experts say you should cap your daily caffeine intake 300 milligrams, and a new study by Consumer Reports found that some energy drinks have more caffeine than is listed on the label.
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Because caffeine isn't usually fatal until you reach numbers closer to 5 grams, David W. Kruse, M.D., primary care sports medicine specialist at the Hoag Orthopedic Institute in Irvine, CA, suspects that a pre-existing condition probably also played a role in these deaths. "There are many factors that change that fatal threshold, such as co-existing medical conditions, hydration levels, and medication use," he says.
No matter what the ultimate cause of these deaths, if you sip energy drinks, forgo them before a workout. Many studies have shown that modest amounts of caffeine can improve performance during endurance exercise, but Dr. Kruse says these studies are done with elite or highly trained athletes.
"The ability to tolerate caffeine with exercise is based on fitness level, hydration status, pre-existing medical conditions, and medication use," he says. "For the recreational athlete or weekend warrior, consuming the amount of caffeine found in an energy drink is not necessary."
In fact, downing an energy drink before exercise can be downright dangerous since it can raise heart rate and blood pressure while at the same time the high level of caffeine may reduce arteries’ ability increase the blood flow necessary to bring more oxygen and nutrients to the heart, Dr. Higgins says.
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Mixing energy drinks with alcohol is equally risky. This combo can impair cognitive function and reduce symptoms of alcohol intoxication, including the depressant effects, thus increasing the probability of accidents and the possibility of development of alcohol dependence, Dr. Higgins says.
"Individuals who are intoxicated are wired from the energy beverage, have a overinflated view of their current level of sobriety, and are likely to take more high-risk behavior due to feeling ‘okay,' 'only a little buzzed,' or 'not too drunk,’" he says. Spiked energy drinks may also increase arrhythmia in patients with underlying heart disease, he adds. “We have seen cases of young college students a rapid heart arrhythmia after consuming several energy-beverage-and-vodka drinks in one session."
Since the allegations, Monster has issued a statement saying, "Neither the science nor the facts support the allegations that have been made. Monster reiterates that its products are and have always been safe."
Tell us, do you drink energy drinks? Have you ever felt any negative effects?
Jennipher Walters is the CEO and co-founder of the healthy living websites FitBottomedGirls.com and FitBottomedMamas.com. A certified personal trainer, lifestyle and weight management coach and group exercise instructor, she also holds an MA in health journalism and regularly writes about all things fitness and wellness for various online publications.