The study, published in Neurology, was based on participants in the Nun Study -- an ongoing clinical study of Alzheimer's disease risk factors in members of the School Sisters of Notre Dame congregation living in the United States.
Study author Dr. Juan Troncoso of Johns Hopkins University in Baltimore says essays from 14 participants written as they entered the convent in their late teens or early 20s were scored on language -- on the number of ideas per 10 words -- and grammar complexity.
The language scores were 20 percent higher in the women without memory problems. The grammar score did not show any difference between the two groups.
"Our results show that an intellectual ability test in the early 20s may predict the likelihood of remaining cognitively normal five or six decades later, even in the presence of a large amount of Alzheimer's disease pathology," Troncoso says in a statement.
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