There are plenty of so-called energy drinks on the market. Most of them have an attractive colour and cool name. But they' re not good for our health because most energy drinks have high levels of caffeine(咖啡因). These drinks are specially aimed (目标) at young people, students, bus y people and sports players. Makers sometimes say their drinks make you better at sports and can keep you awake. But be careful not to drink too much.
Caffeine raises your heartbeat (心跳) . Because of this, the International Olympic Committee has limited their use. The amount of caffeine in most energy drinks is at least as high as in a strong cup of coffee or strong tea.
Australian scientists has found that many teenagers are affected(影响) by caffeine. The results of their study show that 27 percent of boys aged 8~12 take in more caffeine than their parents. There are health problems connected to energy drinks. Just one can of energy drink can make you nervous, have difficulty sleeping and can even cause heart attacks.
