It is now relatively common for students to consume energy drinks to increase their concentration as they study throughout the night. According to Canadian nutritionist Stéphanie Côté, "Energy drinks are the coffee of a new generation ... These drinks are made up of sugar and caffeine and can have a negative impact on health."
According to a 2008 report, 1.5 billion cans of Red Bull were sold in the United States in 2004. Energy drinks are a growing trend for 18 to 24 year olds, and the market is broadening as younger children consume the drinks before physical activity.
However, these drinks aren't recommended either to athletes or to children under the age of 12. "Energy drinks don't hydrate the body efficiently," says Côté. "Because they have too much sugar. And caffeine doesn't necessarily improve physical performance. In high quantities it can increase the risks of fatigue and dehydration."
Several studies have demonstrated that strong doses of caffeine can increase hypertension, cause heart palpitations, provoke irritability and anxiety, and cause headaches and insomnia.
Eurekalert February 5, 2009