But today, a lot of guarana is grown commercially outside the Amazon and it's used most widely as an energy supplement and an ingredient in products such as energy drinks. Guarana products usually ...

“For example, green tea is rich in antioxidants, which many energy drinks don’t have, giving it an edge in terms of health.

Elements like taurine and guarana are found in energy drinks which can increase mental problems, tension and nervousness in you. Children in teenage should be kept away from such drinks.

He's also keen to know about some of the ingredients they contain – from taurine to guarana. What exactly do they do? And are energy drinks safe to drink? Presenter Greg Foot speaks to an expert ...