An Online Wellness Magazine produced by The University of Texas Health Science Center at Houston (UTHealth)

Behind the Buzz

What’s really in those energy drinks?

Sherah, a busy fitness instructor and 36-year-old mother of two children, frequently pops open an energy drink before leading one of her intense, early morning classes. She downs another one in the afternoon, when the morning’s adrenaline rush wears off and her energy flags.

She likes how the drinks boost her energy, but don’t give her the jitters like coffee does. But lately, some new symptoms have her considering cutting back.

“I was starting to get heart palpitations if I drank too many,” she says, adding that a history of heart problems run in her family. “My doctor told me to stop drinking them, and I know they aren’t good for me.”

Energy drinks consumed before exercising may be harmful, says John P. Higgins, MD, an associate professor of medicine at The University of Texas Health Science Center at Houston (UTHealth) Medical School and Director of Exercise Physiology at the Ironman Sports Medicine Institute at Memorial Hermann-Texas Medical Center. Higgins recently published a journal article on energy drinks.

“Energy drinks create an increase in heart rate and blood pressure, which puts extra stress on the heart and makes it work harder,” he says. “At the same time, the high levels of caffeine may reduce the ability of the coronary arteries to open fully and increase the necessary blood flow that brings the heart more oxygen and nutrients.”

Sherah’s not alone in her quest for extra energy, judging from the popularity of energy drinks. According to Beverage Digest, sales for energy drinks increased by nearly 17 percent last year. Since Red Bull made its debut in 1997, more than 500 varieties of energy drinks have been introduced, and more are popping up every day.

“We live in a 24-hour society,” says dietitian Laura Moore, explaining the surging popularity of energy drinks. Moore, Director of the Dietetic Internship Program at The University of Texas School of Public Health, says the drinks were originally intended for athletes, but now are widely marketed to students and active individuals between the ages of 21 and 35. “Energy drinks are used by many to stay awake and increase alertness for studying, working and maintaining often impossible schedules.”

There’s no doubt that energy drinks do their job. But is staying alert and awake around the clock a good thing? And what exactly are we drinking in the first place?

Mostly caffeine and sugar

We’re guzzling caffeine and sugar mostly, Moore says, and lots of it. On average, energy drinks contain about 80 milligrams of caffeine per eight-ounce serving. In comparison, an eight-ounce cup of coffee contains an average of 100 milligrams of caffeine, and soft drinks have about 45 milligrams of caffeine. However, cans of energy drinks often contain more than one serving and caffeine content varies widely—with some brands containing three times the caffeine as others.

Add a heap of sugar to the mix and you get a bonus sugar rush from energy drinks—and potentially hundreds of extra calories you don’t need, Moore says. One energy drink on the market has a whopping 148 calories in an eight-ounce serving.

In moderation, caffeine is not harmful and recent studies show it may actually have some health benefits. For example, small doses of caffeine help boost performance and endurance in athletes. But caffeine affects everyone differently, so some people are more sensitive to it than others. Moore says children and teenagers should avoid energy drinks altogether.

The American Academy of Nutrition and Dietetics recommends adults consume less than 300 milligrams of caffeine daily. Drink or eat more caffeine than that and you may feel anxious, irritable, jittery and get a headache or an upset stomach. According to Higgins, excessive caffeine intake may lead to vomiting, palpitations (fast or irregular heartbeat known as tachycardia, arrhythmia), seizures and even death. He adds that people with significant underlying medical conditions, including heart disease and hypertension, should consult with their health care provider prior to consuming energy drinks.

Besides caffeine and sugar, energy drinks contain a variety of herbal ingredients and stimulants, which, depending on the drink, claim to boost your mood, mental state and even your libido. Common additives include the amino acid taurine, the herbal stimulant guarana (which itself contains high levels of caffeine), B vitamins and ginseng. The word is still out on whether these additives do what they promise. According to the American Academy of Nutrition and Dietetics, the science behind taurine and the B vitamins as energy sources is limited by the role these compounds play in the body, which is to help it use the energy from the foods we eat.

“The negative effects of excess caffeine have been proven, while the positive effects of many of the other additives such as taurine remain unproven, as well as the combined effect of these ingredients in energy beverages,” says Higgins. “In addition, women, nonsmokers and those who don't drink caffeine regularly appear to be more sensitive to caffeine and its side effects.”

More information is needed

While the label on an energy drink may list ingredients, “you really don’t know what you are getting,” Moore says. “The mixture of stimulants and other ingredients is unknown.” Energy drinks are classified by the Food and Drug Administration (FDA) as nutritional supplements, instead of food (like cola), which makes regulation difficult.

“For example, cola drinks have a maximum amount of caffeine that can be added since they are regulated by the FDA. Because energy drinks are not ‘cola’ and are not defined, there is nothing regulating caffeine and other additives in energy drinks,” Moore says.

As their popularity has grown, energy drinks have come under increased scrutiny. The FDA is investigating reports of five deaths that may be associated with the Monster energy drink. Monster is also being sued by the family of a 14-year-old girl with a heart condition who died after drinking two cans of Monster in a 24-hour period.

Also, New York’s attorney general is investigating whether the energy drink industry is deceiving consumers with claims about the ingredients and health value of its products. In particular, investigators are looking at whether companies are overselling the health benefits of added ingredients, while downplaying the role of caffeine in its products. They are also looking at whether adding guarana violates laws that ban putting more than one source of caffeine in a beverage without listing the total amount on the label.

A little energy goes a long way

Despite the lack of regulation, energy drinks likely will continue to be popular as long as there are cramming students, late night partiers and athletes looking for an edge. But that edge only goes so far, Moore warns.

“Energy drinks are counterproductive to most athletes, because they carry a high sugar load and can cause dehydration,” she says. “In some cases, the excessive caffeine found in energy drinks today can lead to serious impairment in performance.”

Combining energy drinks with alcohol is dangerous, Moore adds, because the caffeine masks the effects of alcohol. Caffeine doesn’t sober people up. It just makes them wide awake. So, partiers slamming down Red Bull cocktails are still getting drunk, but do not “feel it.” That’s an appealing state of mind for the late-night crowd, but it also increases the risk for driving drunk and indulging in risky behaviors.

Higgins adds that the combination of energy drinks and alcohol might also increase significant arrhythmia in patients with underlying heart disease. “We have seen cases where young college students develop a rapid heart arrhythmia after consuming several energy drinks combined with vodka [in a single session],” he says.

So what’s the alternative?

A busy professional herself, Moore understands the appeal of energy drinks, but advises a more balanced approach to staying awake and alert.

“Exercising regularly, getting plenty of rest, and eating healthy–choosing a balanced diet of fruits, vegetables, whole grains, low-fat proteins and dairy–will naturally increase your energy level,” Moore says.

“And when exercising under one hour, avoid exercising in the hottest part of the day, and keep well hydrated with water before, during and after exercise,” Higgins adds. “For exercise over an hour, take plenty of breaks and hydrate with water or sports drinks to prevent dehydration.”

Madeline Estep contributed to this story.

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