Reporters are not scientists, so most of the time they leave out crucial details to make the findings of studies sound more groundbreaking than they really are. I haven't read the original research, but I wouldn't be surprised if that regeneration is modest and slow. Still, it's pretty impressive since I think we assumed for a long time that the only organ to be able to regenerate itself was the liver. I posted another post about a month ago or so about the BBC-Horizon documentary "Eat, Fast and Live Longer", one of the segments explains how fasting can also promote neuron regeneration and growth. Since I'm almost positive the researcher of this study and one of the ones on the doc is the same, I would not be surprised if the mechanisms for the pancreatic cell regeneration are similar to the ones that promote neuron regeneration too. EDIT:  Yes, it's the same guy (Dr Valter Longo from the University of Southern California) I just checked the video on the post I mentioned above, and around the 18:30 minute mark you'll see Longo's segment, around the 43:00 mark it's the segment on neuron regeneration. The presenter of the doc (Dr. Michael Mosley) wrote a book about his summary of the fasting research methods he explored, it's called "The Fast Diet", you can check it on Amazon.