Why prunes are good for you

What would you prefer: a prune or a dried plum? They're the same thing, of course, but the latter has more seductive connotations. That's why the sticky brown-black fruit has been renamed in the US.
Prunes come in handy when the only fresh plums on sale are the tough-skinned, furry-textured imported sort, although, if we're honest, their natural sweetness, squidgy succulence and chewy darkness give them more of the wanton appeal of chocolate than fruit.
Many prunes we eat come from California, but their European base is the south-west of France, renowned for its pruneaux d'Agen with their glorious affinity for armagnac. In autumn, markets there sell these plums fresh or mi-cuit (half-dried) before they disappear into kilns for more thorough dehydration.

Why are they good for me?

They are a great source of phenols, which help to prevent oxygen damage to cells. Their sweetness doesn't make them the best fruit choice for slimmers, but their soluble fibre does slow down absorption of glucose, stabilising blood-sugar levels. Prunes are one of the best foods for vitamin K, vital for strong bones and blood clotting.
Amid much controversy, the European Food Safety Agency has ruled that prunes are not a laxative and can't be sold at such. Be your own judge: suck them and see.

Source  - Guardian