Article: What's wrong w/ too much caffeine?

Many of us reach for a cup of tea or coffee when we’re tired, but why? It’s because these and some other drinks contain the stimulant caffeine. But how does it affect the body? And how much is too much? In this article we look at the effects of the stimulant, found in chocolate, coffee, cola and fizzy drinks, energy drinks and caffeine tablets, and explore the recommended amounts we should be having in our diets. Part of Wellcome Trust's Big Picture: Food and Diet (www.wellcome.ac.uk/bigpicture/food). See there for more food mythbusting.