Can eating more than six banas at once time can kill you?

-It's sometimes said that eating a lot of of bananas at once could be dangerous - it has even been suggested that eating more than six in one sitting could kill you. Can this really be true?

Bananas are one of the world's most popular fruits, stuffed with vitamins and minerals. On the face of it they are good for you, so why do some people think they could be fatal?

One well-known figure who has spread this idea around is Karl Pilkington, the grumpy friend of comedian Ricky Gervais.

"It is a fact. Potassium levels are dangerously high if you have six bananas... I saw a bowl of bananas. There's six bananas there. You know why there's only six? Seven would be dangerous."

So how dangerous is potassium? Actually, it is crucial for survival and can be found "within every single cell of the body," says Catherine Collins, a dietitian at St George's Hospital in London.

"We use it to help generate an electrical charge which helps the cell function properly. It helps keep your heart rate steady, it helps trigger insulin release from the pancreas to help control blood sugars, and more importantly keeps blood pressure in check."

On the other hand, if the level of potassium in the body is too low or too high it can result in an irregular heartbeat, stomach pain, nausea and diarrhoea. Potassium chloride is even one of the chemicals used in lethal injections in the US, as extremely high doses can cause cardiac arrest.