Among the healthy elderly, people with higher education levels exhibit more severe brain shrinkage with age than people with fewer years of education. Yet, these seniors do not show severe problems with their memory or thinking, according to a researcher at Henry Ford Health System.
The study published in the July issue of the journal Neurology, supports the "reserve hypothesis" -- that while more educated people have greater age-associated brain shrinkage, they are afforded greater protection from age-related mental impairment and possibly dementia.
This study is the first of its kind to look at the biology of the reserve hypothesis in healthy older adults.
"Our research shows that education exerts a protective effect," said C. Edward Coffey, M.D., chair of Henry Ford's Department of Psychiatry and the study's principal investigator. "Education doesn't reduce brain changes associated with disease or aging, but rather enables more educated individuals to resist the influence of deteriorating brain structure by maintaining better cognitive and behavioral function."
The research pool consisted of 320 healthy men and women ages 66 to 90 living independently in the community. All were pre-screened for impairment using a mental state examination. Researchers used magnetic resonance imaging (MRI) technology to measure brain size. The MRI images revealed the following:
Brain shrinkage, as demonstrated by an increase in cerebrospinal fluid around the outside of the brain, was significantly greater in people with higher education.
Researchers counted years of education starting with first grade. For each year of education, they found about 1/3 tsp. (1.77 ml) more cerebrospinal fluid around the brain. For example, among elderly persons of similar age, sex and intracranial size, those with 16 years of education had approximately 8 to 10 percent more cerebrospinal fluid volume than those with only four years of education.