There have been reports over time about the effects of sleep deprivation (less than six hours a night). They generally concluded that lack of sleep affects physical health in many different ways including the ability to heal.
It highlighted something I have always thought about affecting my own health. Throughout my life I very rarely got a full nights sleep from an early age. Not insomnia...just I prefer the night for working uninterrupted etc. But of course I had to get up the same time as everyone else and so had less sleep. (Now I am retired I sleep too much - a possible sign that all is not well we are told, rather than a cause of ill health but that's a linked but another story).
So aside from the usual problem of ones current state of possible insomnia it might be interesting for someone to do a survey on the sleep patterns of people diagnosed with Parkinsons covering a lifetime. Maybe we all were night owls and did ourselves irreparable damage in the past, or maybe we weren't.
Is there a link?
(I never ate properly either which might 'muddy the waters' of research)