Memory slips can indicate heightened risk of dementia in later years, according to new research. The new study, which was published in the September 24, 2014 online issue of Neurology®, the medical journal of the American Academy of Neurology, indicates that individuals without dementia who start to report issues with their memory may be at an increased risk of developing dementia later, despite a lack of clinical signs of the disease.

Study author Richard J. Kryscio, PhD, from the University of Kentucky in Lexington, said in a statement, “What’s notable about our study is the time it took for this transition to dementia or clinical impairment to occur—about 12 years for dementia and nine years for clinical impairment—after the memory complaints began.” He continued, “These findings suggest that there may be a window for intervention before a diagnosable problem shows up.”

A total of 531 people were involved in the study, with an average age of 73 and no signs of dementia and were asked annually if they noticed any changes in their memory. The participants were also provided with yearly thinking and memory tests for an average of 10 years. Following death, 243 of the participants’ brains were looked at for any evidence of Alzheimer’s disease.

The study results show that 56 percent of the study participants in total reported memory changes, with an average age of 82. The study also found that individuals who reported memory complaints were three times more likely to develop problems with their memory and thinking. Approximately one in six study participants developed dementia during the study, with 80 percent having initially reported memory changes.

According to the Alzheimer’s Association, an estimated 5.2 million Americans have Alzheimer’s disease in 2014.