Feb. 25 (UPI) -- Women experience sharper declines in cognitive function as they age compared to men, a study published Thursday by JAMA Network Open found.
Women generally score higher than men, however, on several measures of cognition before the onset of decline, the data showed.
The findings suggest that women have "greater cognitive reserve" than men, but may suffer "faster cognitive decline," the researchers said.
"Women may thus have greater needs for caregiving and functional support resources, particularly given women's longer life expectancy compared with men," researchers from the University of Michigan wrote.
They "may also have greater need for serial cognitive assessment to allow for earlier detection of cognitive decline," they said.
About 6 million people in the United States have dementia, while about 11% of older adults have evidence of cognitive decline, according to the U.S. Centers for Disease Control and Prevention.
Although the prevalence of cognitive decline has fallen in the United States over the past 25 years, reductions "were less in women than in men," the University of Michigan researchers said.
For this study, the researchers used data from several studies to track the cognitive performance of more than 26,000 adults in the United States over an eight-year period.
The studies included in the analysis used multiple assessments for cognitive function, according to the researchers.
Participants ranged in age from 51 to 67 years when the study started, and they were assessed for global cognition, executive function and memory.
Global cognition measures language comprehension, perception and decision-making, among other tasks, while executive function includes thinking, working memory and self-control.
Women performed significantly better than men on various tests for cognitive function at the start of the analysis, but showed higher rates of decline annually over the course of the study period, the data showed.
"Women might have faster cognitive decline than men because of differences in sex hormones, structural brain development [and] genetics," among other other factors, the researchers wrote.
"Women also appear to have lower gray matter volume, so they might be more vulnerable to both the accelerated gray volume loss that occurs with aging," they said.