The key in all this is to remember that it's not so called "challenging behaviour" it's actual challenging behaviour. My coccyx and fingers have been broken not "so called broken" but actually broken. Because that's what caring for someone with challenging behaviours is like. Not "so called" like, actually like.
Chocolate may make the heart grow fonder, but does it make the brain grow larger? This week a New England Journal of Medicine article investigated whether a correlation existed between a countries per capita chocolate consumption (mostly measured through Lindt® dark chocolate consumption) and their cumulative amount of Nobel Prize winners.
We take it for granted, but memory is fundamental to everything you do. As soon as you start losing your memory your whole life goes into meltdown. When my mother started having trouble with her memory it was difficult because she was only in her 50s. At the time we just thought she was being eccentric. She had always been funny, always saying the wrong thing at the wrong time and we would think 'I can't believe she said that!' But this was an exaggerated form. She started crying a lot.
The connection appears to be strong. People with type 2 diabetes are much more likely to develop Alzheimer's disease than their healthy counterparts (up to 65% [2]). In fact, the association also appears to be strong linking the metabolic syndrome, essentially a pre-diabetic state, and Alzheimer's disease [3].