CHICAGO (AP) – New research documents another decline in dementia rates but experts say the rising numbers of older Americans may halt that trend unless better ways are found to keep brains healthy.

The study released Monday shows the rate of Alzheimer’s disease and other dementias in adults aged 65 and up dropped to about 9 percent in 2012 from nearly 12 percent in 2000. That continues a fall noted in earlier research.

Older adults with the most schooling had the lowest dementia rates, and the average education level increased during the study years.

The study was led by University of Michigan researchers and was published in JAMA Internal Medicine. The National Institute on Aging paid for the research.