I also have heard ( and my doctors have told me as well) that the liver regenerates and/or stimulates glutathione (sp?) (anybody care to explain this? i'm not quite sure what it means myself just sharing....) itself during particular hours of the night...roughly from 11 pm to 3 am . This explains why when we sleep too late, or during daytime (especially those who work night shifts ) we don't feel as rested as compared to sleeping during proper hours. This also explains why when I keep odd sleeping hours (say, sleeping at 5 am and waking up at 4 pm...it may be 11 hours of sleep but HELL I still feel fucking tired) it's because my liver was not able to regenerate properly and so I dont feel truly rested.
I'm inclined to believe this based on my personal experinces with sleeping at different hours of the day , or withholding sleep at all as compared to sleeping properly, at the right times. It's our livers!
