Dementia may have a greater role to play in memory loss than had previously been realised.
Research conducted by the Rush Alzheimer's Disease Centre has revealed rather than simply a result of the onset of old age, memory loss is more likely to be the result of the brain lesions associated with the illness.
Robert Wilson, neuropsychologist at Rush University Medical centre, commented: "The very early mild cognitive changes once thought to be normal aging are really the first signs of progressive dementia, in particular Alzheimer's disease.
"The pathology in the brain related to Alzheimer's and other dementias has a much greater impact on memory function in old age than we previously recognised."
He added that the course of the disease could be altered if research such as this allowed people to recognise the earliest changes of memory loss related to Alzheimer's.
Over the course of 13 years, more than 350 nuns, priests and brothers participated in the research.
After their deaths, their brains were examined for the lesions associated with dementia.