With or without dementia, a person’s mental capacity diminishes years before they die, according to new research.

Researchers at the University of Sweden followed the mental progression of 288 people without dementia from the age of 70 until their deaths. Over the course of 30 years, researchers evaluated the participants’ mental skills and made some connections between the onset of cognitive decline and eventual death.
On average, a person starts to lose perceptual speed, or the ability to compare figures, 15 years before they die, researchers found. Spatial ability begins to wane eight years before they expire. Verbal skills are the last to go, and don’t begin to decline until six-and-a-half years before death, according to the report.

Reasons for non-dementia related mental decline could include health factors such as cardiovascular disease, according to researchers. They also speculate that frailty and diminished overall health in old age could lead to inactivity and a lack of both physical and mental stimulation. The report appears in the August 27 online edition of the journal Neurology.