Energy Drinks and Your Heart

Ask our expert if they're safe

About our Expert

Laura Dunne, M.D., is a family medicine physician with Lehigh Valley Health Network.

• Do energy drinks hurt your heart?
• How powerful are the stimulants in energy drinks?
• Are there other risks from drinking energy drinks?
• What happens when you mix energy drinks with alcohol?
• What are better alternatives?

Q: Do energy drinks hurt your heart?

A: Most healthy people can have an energy drink (Jolt, Red Bull or Rockstar, for example) without experiencing any problems. But energy drinks contain huge amounts of legal stimulants such as caffeine, and have been shown to boost both blood pressure and heart rate, especially if you drink them regularly. In some people, they cause heart palpitations. Even healthy young people who drank two cans of a relatively mild energy drink every day for a week in one study saw their blood pressure and heart rate increase about 10 percent for several hours after drinking. That could be dangerous for people with high blood pressure or heart disease, so you should avoid energy drinks if you have any cardiovascular risks.

Q: How powerful are the stimulants in energy drinks?

A: Most energy drinks contain between 120 to 200 mg of caffeine, and some contain as much as 300 or even 500 mg. That's far more than the 34 mg in a can of cola or the 100 mg in a cup of coffee. Besides high levels of caffeine, a lot of drinks contain other stimulants such as taurine (an amino acid) and guarana (an herb that contains even more caffeine). It can be difficult to know the total dose of stimulants you're getting because amounts often aren't listed on the label.

Q: Are there other risks from drinking energy drinks?

A: They can make you dehydrated, keep you from sleeping and cause headaches. And because they're served cold, people tend to drink them fast, which can give you a quick surge of energy followed by a sudden drop (sometimes called a jolt-and-crash response). Some people, especially younger adults, like to mix energy drinks with alcohol, which raises its own set of dangers.

Q: What happens when you mix energy drinks with alcohol?

A: The stimulants counteract alcohol's tendency to cause drowsiness, which would otherwise make you stop drinking. Some younger adults deliberately use energy drinks to bypass this natural inhibition so they can party longer. Some manufacturers are now making premixed alcoholic energy drinks and specifically targeting the young adult market. Drinking these products makes you increasingly impaired as your blood alcohol level rises, but the stimulants mask your intoxication so it feels like you're in better shape than you really are. People who mix alcohol and energy drinks are significantly more likely to drink heavily, ride in a car with an intoxicated driver, engage in unhealthy sexual behavior, become injured or require medical treatment-in addition to increasing the cardiac risks of arrythmia and high blood pressure.

Q: What are better alternatives?

A: Fatigue is the first sign of dehydration, so instead of picking up an energy drink, use water to help you refuel. Beyond water, sports drinks like Gatorade can give you some simple sugars as well as fluid. More recently, newer brands like Odwalla and Special K have come out with protein drinks. They have more staying power than sugar-based drinks because the body uses protein energy over a longer period of time than sugar. But some of these drinks can be high in calories, which is another reason to stick with water.

This page last updated 6/9/09 12:57 PM