EU prunes

If you have ever eaten prunes, or watch old people eat them fervently in search of movement, then you know they work.

But the EU thinks differently.

Having investigated the effects of the food on three subject, the EU concluded:

"The evidence provided is insufficient to establish a cause and effect relationship between the consumption of dried plums of 'prune' cultivars (Prunus domestica L.) and maintenance of normal bowel function."

Which evidence did they focus on?