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Food for Thought Food for Thought

Are Energy Drinks Safe?

February 05, 2013

By Kate Sweeney, M.S., B.S.
Brigham and Women's Hospital

Ever since Red Bull appeared on store shelves in 1997, the popularity of energy drinks has soared. In 2006, the industry made more than $3.2 billion. Sales are expected to reach $20 billion in 2013. Along with this success comes the growing concern that these products may be harmful to consumers.

In November 2012, the Food and Drug Administration (FDA) released a report showing that 13 deaths may be connected to use of Monster Energy and 5-Hour Energy. While the report does not mean these products directly caused the deaths, it does bring attention to their ingredients, safety and regulation.

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What's in Energy Drinks?

Caffeine is the most common ingredient in energy drinks. It stimulates the nervous system and can boost energy and alertness. Most adults can tolerate 200 milligrams a day, although it affects people differently. Some can sip coffee all day, while others are jittery after one cup.

Certain groups, like pregnant women, should limit caffeine. Children and people with heart disease or panic disorders should avoid it. More than 200 milligrams of caffeine can cause insomnia, nervousness, headache, heart palpitations and nausea.

Sugar is usually in the form of sucrose or high-fructose corn syrup. A 16-ounce can of Monster has 54 grams of sugar. This is just over 1/4 cup of sugar. Consuming too much sugar over a long period of time is associated with insulin resistance, diabetes and obesity.

L-carnitine and taurine are amino acids. L-carnitine is made in the liver and kidneys and increases metabolism. Taurine occurs naturally in the body and comes from eating meat.

B-vitamins such as B12, B6 and niacin are water-soluble vitamins needed for proper cell functioning.

Guarana and ginseng are plant extracts. Guarana is found in the Amazon. It has more caffeine than any other plant in the world. Ginseng is grown in Asia. A 2010 study showed too much ginseng can cause hypotension (low blood pressure), edema (swelling), headache, vertigo, fever and heart palpitations.

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Concerns About Caffeine

Researchers are studying the potential medical problems associated with caffeine in energy drinks.

Some products have more than 200 milligrams in a serving. Caffeine intake can add up if someone gets more than one serving a day. Below is a comparison of the caffeine in several products.


Serving size (ounces)

Caffeine (mg)


Sugar (grams)


5-Hour Energy
Full Throttle
Dunkin' Donuts Coffee
Monster Energy
Amp Energy
Green tea

Sources: Consumer Reports and

It can be difficult to determine how much caffeine is in a product. In their December 2012 issue, Consumer Reports found that 11 of 27 drinks did not list caffeine content. And 5 of the 16 drinks tested for caffeine content had, on average, 20% more caffeine than their labels said. Consumers want the FDA to set a limit to the amount of caffeine allowed and to require manufacturers to list the amount on their labels.

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Other Safety Concerns

  • Many people do not "sip" energy drinks as they do coffee or tea. Fast drinking can increase blood concentrations of caffeine quickly, which can increase risk for side effects.
  • Energy drinks are marketed to teens. Because many teems weigh less than adults, they end up with a higher concentration of caffeine in their bodies. A 2010 study showed that young adults have been admitted to emergency rooms due to caffeine overdoses linked to consumption of guarana-rich energy drinks.
  • Energy drinks are popular to mix with alcohol. The caffeine can override sleepiness and delay feeling drunk. This can cause people to drink more. The Federal Drug Abuse Warning Network estimates that over 3,000 trips to the emergency room from 2004-2007 were connected to energy drinks mixed with alcohol or drugs.
  • Frequent use may increase risk for side effects. A survey of over 1,000 service members deployed to Afghanistan in 2010 found that 45% consumed one or more energy drinks per day; 14% consumed three or more. The researchers found the more drinks people had, the less sleep per night they reported.

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Are Energy Drinks Regulated?

The FDA considers energy drinks "dietary supplements," not food. This means that:


  • Manufacturers can sell a product without proving its ingredients are safe. They also don't have to list ingredients on labels. The FDA, however, must prove an ingredient is unsafe and then find the products it is in before taking it off the market.
  • Manufacturers are not required by law to report serious side effects to the FDA. If a report is made, the FDA must investigate whether the product was to blame. In order to take a product off store shelves, the FDA must show that the product directly caused the side effect.

Current regulations leave consumers exposed to potentially harmful products.

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The Bottom Line

Energy drinks have not been proven safe. And they are not recommended as part of a healthful diet. Here are some ways to increase you energy and alertness:


  • Eat some fruits, vegetables and lean protein every 3 to 4 hours.
  • Avoid frequent high-fat meals.
  • Get 6 to 8 hours of sleep a night.
  • Drink 6 to 8 glasses of water a day.
  • Exercise 30 minutes a day.

Ballard, S., Wellborn-Kim, J., and Clarkson, K. 2010. Effects of commercial energy drink consumption on athletic performance and body composition. Phys Sportsmed. 38(1):107-117.

Higgins, J., Tuttle, T., and Higgins, C. "Energy beverages: Content and safety." Mayo Clinic Proceedings. 2010; 85(11):1033-1041.

International Food Information Council. "Caffeine & Health: Clarifying the controversy." April 16, 2008. Available at

Malinauskas, B., Aeby, V., Overton, R., Carpenter-Aeby, T., and Barber-Heidal, K. "A survey of energy drink patterns among college students." Nutrition Journal. 2007; 6:35.

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Kate Sweeney received her Masters in Nutrition Communication from the Friedman School of Nutrition Science and Policy and her B.S. in biology from Tufts University. She is currently a dietetic intern at Brigham and Women's Hospital.

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