Dementia , including Alzheimer’s disease , results in memory and thinking problems severe enough to disrupt a person’s daily life. But researchers believe that dementia begins to develop a decade or more before these cognitive symptoms occur. There is some evidence that problems with physical function (eg, reduced walking speed) may precede the onset of dementia, but research to determine what dementia’s early symptoms are and when they might occur has been limited.

A new study in the May 22, 2006 issue of the Archives of Internal Medicine found that people who scored lower on physical performance tests were at significantly greater risk of developing dementia six years later.

About the Study

This study included 2,288 people who were aged 65 or older and free from dementia when the study began (though some did show signs of mild cognitive impairment). Before the study began, the participants took physical performance tests to check for problems with walking, standing from a seated position, balance while standing, and grip strength. Researchers used a questionnaire to assess the participants’ cognitive function (ie, memory and thinking skills) every two years. The researchers followed the participants for six years, tracking who developed dementia.

During the study, 319 participants developed dementia, including 221 cases of Alzheimer’s disease. The participants who scored better on the physical function tests were significantly more likely to be dementia-free after six years than those who scored worse. Walking problems were associated with an increased risk of developing dementia in all participants. In those who showed no signs of cognitive impairment before the study began, poor balance was associated with an increased risk of dementia. In those who had mild cognitive impairment before the study began, problems with grip strength were associated with an increased risk of dementia.

How Does This Affect You?

These findings suggest that older people who have problems with physical function are more likely to develop dementia in the coming years. This is not surprising, since regular exercise has been associated with a lower rate of cognitive decline and a reduced risk of dementia.

Even before memory and thinking problems become evident, trouble with walking, balance, and grip strength may signal an increased risk of developing dementia. Although a study like this cannot say whether an increase in physical activity can delay the onset of dementia, other studies have suggested that this is the case. If you experience problems with physical functioning as you age, talk with your doctor about becoming more active and engaging in a regular exercise program.