ST. PAUL, Minn -- How well your mind works in old age depends on physical fitness and your IQ score as a child, according to a study published in the October 10, 2006, issue of Neurology, the scientific journal of the American Academy of Neurology.
In determining whether physical fitness is associated with more successful cognitive aging, the study examined 460 men and women who had been participants of the Scottish Mental Survey of 1932. The participants were tested using the same cognitive test at age 11 and age 79.
Results show physical fitness contributed more than three percent of the differences in cognitive ability in old age after accounting for participant's test scores at age 11. Physical fitness is defined by time to walk six meters, grip strength and lung function.
"The other remarkable result was that childhood IQ was significantly related to lung function at age 79," said study author Ian Deary, PhD, FRCPE, with the University of Edinburgh in Scotland. "Participants with a high IQ as a child were more likely to have better lung function at age 79. This could be because people with higher intelligence might respond more favorably to health messages about staying fit."
However, the study found physical fitness has a greater impact on cognitive ability in old age than childhood IQ.
"The important result of the study is that fitness contributes to better cognitive ability in old age," says Deary. "Thus, two people starting out with the same IQ at age 11, the fitter person at age 79 will, on average, have better cognitive function."
The study also found occupation and education were associated with fitness at age 79. People in more professional occupations and with more education had better fitness and higher cognitive test scores.
Deary says intervention programs aimed at making older people fitter are good candidates to improve cognitive aging.