Energy drinks (and energy shots) are nonalcoholic beverages that typically contain large amounts of caffeine. Depending on the brand, ingredients may also include an amino acid called taurine, B vitamins, a legal stimulant called guarana, and lots of sugar. Energy drinks have become increasingly popular because they offer a quick “pick me up.” They are used by athletes to enhance performance, college students to increase mental alertness, and working people to provide a quick energy boost. Popular brands include Monster, Red Bull, Rock Star, and 5 Hour Energy. The manufacturers and some fitness publications extol health benefits of the B vitamins in these drinks, touting their roles in maintaining cardiovascular, nervous system and digestive system health and even fighting cancer. And due to their high sugar content (as much as 8-10 tsp of sugar per can), some athletes use energy drinks when they are carbo loading before an event. However, there is growing evidence that energy drinks can have serious negative health effects, especially in children, teenagers, and young adults. Studies show that it is easy to become dependent on energy drinks and the reasons are twofold. First, the caffeine and sugar combination in these beverages provides a quick burst of energy followed by a “crash” that makes you feel tired and lethargic again. Many people counter this by drinking another energy drink. Secondly, headaches, including migraines, are common effects of caffeine withdrawal, further encouraging continued use of energy drinks. The high caffeine content of energy drinks can also cause insomnia, jitters, and increases in blood pressure. Too much niacin (one of the vitamins in energy drinks) can cause dizziness and rapid heart rate. And although energy drinks are often associated with sports and athletes, people who drink them regularly are much more likely to be obese. The number of emergency room visits related to energy drinks has more than doubled in recent years, often due to serious heart and blood vessel problems such as heart rhythm disturbances, and elevated heart rate and blood pressure.

The bottom line: Although energy drinks can give you a quick boost when used occasionally, it is best to avoid frequent or long term use. And to prevent serious side effects, limit intake to no more than one.