Bananas cultivation may have originated in Malaysia over 4000 years ago, but has since spread to Africa, the Middle East and America through colonisation. Bananas are worthy of nutritional consideration because so many are produced and consumed Worldwide. In fact bananas are the second leading fruit crop. There are hundreds of varieties of banana, but they can be split into two main types. Plantain bananas (Musa paradisiaca) are high in starch and low in sugar and as a result are usually cooked before eating. Plantain bananas are used in cooking in a similar way to vegetables such as the potato, and may be cooked often by frying. Plantain bananas are usually green in colour, but can ripen to a black colour. Sweet bananas are also starchy, but can ripen which allows much of the starch to be converted to sugar, and this allows consumption raw. As sweet bananas ripen they pass from green to yellow and finally to black. The most common sweet banana in the West is the Big Mike or Gros Michael (Musa sapientum).
Sweet bananas are renowned for their potassium content, which is high compared to most fruits. However some fruits such as avocados have an even higher potassium content compared to bananas. As well as potassium, bananas also contain high amounts of magnesium. The potassium and magnesium content of bananas makes them a useful food to incorporate as part of a blood pressure lowering diet. This is because these two minerals have been shown to produce blood pressure lowering and other cardioprotective effects in humans. As well as potassium sweet bananas are also a good source of vitamin C, a feature they share with most fruits. The B vitamins in bananas include riboflavin, vitamin B6 (pyridoxine) and biotin. One nutritional property of bananas worthy of consideration is their low water content, in comparison to most fruit. This makes their energy more concentrated that in most other fruits and this favours their use by athletes who require sugars for the resynthesis of glycogen stores following exercise.