Article continues below advertisementDiane Keaton's health woes are being exposed after her sad death at age 79.In a bombshell new report from NewsNation, multiple sources revealed that the Oscar-winning actress had been battling dementia "for years" before she lost her life on Saturday, October 11.Keaton, whose cause of death was listed as bacterial pneumonia, had not been seen publicly since April.Article continues below advertisementSource: MEGADiane Keaton allegedly battled dementia before her death.