NEW YORK — If you're lucky enough to live into your 90s, how well will your brain hold up? You may have an edge over people who got there ahead of you, a new study hints.
Researchers found that on tests of mental abilities, a group of 95-year-old Danes scored better than a group of Danes born 10 years earlier, who had been tested when they were about the same age.
In a standard simple test, for example, 23 percent of them scored in the highest category, compared to 13 percent of the earlier-born group. Out of the 30 questions and tasks, members of the later-born group averaged two more correct responses than the earlier-born group did. The results were released Wednesday by the journal Lancet.
Why the better mental performance? It wasn't just better education, but beyond that the researchers could only guess at things like more intellectual stimulation and better diets earlier in life.
More people are living to such old ages. The U.S. census counted 425,000 Americans age 95 and older in 2010, a 26 percent increase over the total in 2000.
The mental testing compared 1,814 elderly Danes examined in 1998 to the later-born group of 1,247 Danes tested in 2010. The researchers also found that later-born Danes were better able to carry out basic living tasks like getting out of bed or a chair. So they were functioning better overall, the study concluded.
Lead author Dr. Kaare Christensen, head of the Danish Aging Research Center at the University of Southern Denmark in Odense, said he imagines that in the future, Danes who live into their 90s will continue to be better off than their predecessors. He was cautious about applying the results to the United States, although he said the availability of education in the U.S. after World War II would be a plus.
Dr. James Pacala, associate head of the department of family medicine and community health at the University of Minnesota Medical School, who didn't participate in the study, said he suspects the same trends are present in the United States.
He also said the findings fit with previous work that shows people are functioning better at given ages than they used to.
But Pacala, who heads the board of the American Geriatrics Society, noted that even in the better-functioning group of Danes, at least 40 percent and probably more had dementia.
Denise Park, an expert in mental function and aging at the University of Texas in Dallas, called the mental test results provocative but said it's not clear why the differences appeared. She said she would want to know if the effect holds up for 80-year-olds as well.
"If it's real, it should," she said.