THURSDAY, July 11 (HealthDay News) -- People in their 90s today are mentally sharper than those who were in their 90s a decade ago, a new study contends.

The Danish researchers compared 2,262 people who were born in 1905 and still alive in 1998 (aged 92 to 93) with 1,584 people who were born in 1915 and still alive in 2010 (aged 94 to 95).

Appearing online July 11 in The Lancet, the study "challenges speculations that the improving longevity is the result of the survival of very frail and disabled elderly people," study leader Professor Kaare Christensen, at the University of Southern Denmark, said in a journal news release.

All the study participants underwent tests to assess their mental skills and their ability to carry out daily living tasks. Not only were the people in 1915 group 32 percent more likely to reach the age of 95 than those in the 1905 group, they did better on the tests of mental abilities and activities of daily living.

On average, the people in the 1915 group had slightly higher levels of education. But the difference was only statistically significant in women, who had overall very low levels of education in both groups. This suggests that the better average mental ability in the 1915 group is not likely due to improved education, according to the study authors.

"Our results suggest that the functioning of people who reach their nineties is improving in Denmark, and increasing longevity associated with improved living conditions and health care may result in not just longer lives, but also that elderly are functioning better for longer than in earlier generations," Christensen said.

The findings also challenge predictions about the future burden of dementia in an aging population, according to an accompanying editorial by Marcel Olde Rikkert and Rene Melis, of Radboud University Medical Centre in Nijmegen, in the Netherlands.

More information

The Society for Neuroscience has more about aging and brain health.