New research suggests women may begin to lose their mental acuity as early as their 50s.
University of California, Los Angeles, (UCLA) researchers followed the same group of healthy women for 10 years after menopause, and discovered that their average decline in mental processing ability was five percent during the decade-long period.
The investigators tracked cognitive processing speed — which includes speed of perception and reaction =– and found an average decline of around one percent every two years.
Moreover, verbal memory also declined on average around one percent every five years.
The new findings are in contrast to previous longitudinal studies in midlife women that had failed to consistently detect these cognitive declines.
The study is published in the journal PLOS ONE.
For this study, the researchers accounted for what are called “practice effects,” which is when repeat testing using the same tests in the same individuals influence the results.
Practice effects mask some effects of the menopause transition. The new technique allowed investigators to uncover evidence of declines in two domains of cognitive functioning, processing speed, and verbal memory.
In the study, researchers examined data on more than 2,000 healthy women enrolled in the Study of Women’s Health Across the Nation, or SWAN. In the study, women were tested regularly over several years to measure cognitive changes.
The women were in their 40s when they enrolled in 1996 and were followed every one to two years for a median period of 6.5 years.
Investigators launched the investigation because women in their 40s and 50s may begin to find they are forgetting things more often. They may also have the perception they are slower to react to situations.
Researchers wanted to discover if the events — such as a gradual slowing of physical reaction time, running speed, metabolic rate, and other declines that we all experience in midlife — were a part of the usual aging process.
The authors of the study were Drs. Arun Karlamangla, MeiHua Huang and Gail Greendale, and WeiJuan Han, M.S., of UCLA, and Dr. Margie Lachman of Brandeis University.