New UCLA research suggests that for seniors age 70 and older, socioeconomic status does not play a major role in the brain's continued ability to function. However, seniors who have never been married and widowers seem to perform more poorly as they age.
Previous studies on age-related cognitive decline have not adequately clarified the role demographics and socioeconomic status might play in the rate of decline. Some small and short-term studies have found small socioeconomic differences in decline rates, while others have shown none at all, leaving the issue murky at best.
In a new national study of older Americans 70-plus years of age (mean age 75) published in the Aug. 1 issue of the American Journal of Epidemiology, researchers from the David Geffen School of Medicine at UCLA and the UCLA School of Public Health found that rates of cognitive decline over a nine-year period were similar across socioeconomic and racial and ethnic groups. The findings indicate that disparities in cognitive functioning among older Americans of different groups are almost entirely due to differences in the cognitive peaks they reached earlier in life, not to differences in rates of decline.
The study is available online at http://aje.oxfordjournals.org/cgi/reprint/170/3/331.
"It has been known that cognitive performance at any given age appears to depend on demographic characteristics; the more educated, for instance, perform better," said lead investigator Dr. Arun Karlamangla, associate professor of medicine in the division of geriatrics at the Geffen School of Medicine. "But though there are differences in the level of performance you start with in your late 60s, this study's surprise is that the rate of decline in your 70s is the same for every group."
The study was based on data from 6,476 adults born prior to 1924 culled from the Study of Assets and Health Dynamics Among the Oldest Old (AHEAD). Participants were tested five times between 1993 and 2002 on various memory and cognition items, including word recall, the "serial sevens" subtraction test, orientation to time, attention, language and knowledge of current affairs.