Getting very old does not necessarily come with the absolute decline in mental and physical functioning that is commonly expected, new research shows.

A large-scale study of two groups of nonagenarians — people in their 90s — in Denmark finds that those born in 1915 not only lived longer than people born a decade earlier, but they also scored significantly better on measures of cognitive ability and activities of daily living.

Even after adjusting for increases in education in a decade, people born in 1915 "still performed better in the cognitive measures, which suggests that changes in other factors such as nutrition, burden of infectious disease, work environment, intellectual stimulation and general living conditions also play an important part in the improvement of cognitive functioning," says the study, published online today by the science journal The Lancet.

The findings challenge speculation that improving longevity "is the result of the survival of very frail and disabled elderly people," says lead researcher Kaare Christensen,professor of epidemiology at the University of Southern Denmark in Odense and director of the Danish Aging Research Center.

"That's not to say that everyone in the later cohort was healthy, smart and functioning well, but compared to those who were born 10 years earlier, not only were more living to a higher age, but they were functioning better," Christensen says.

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