The study followed 2,288 Group Health members age 65 and older for six years. At the start, none showed any signs of dementia or Alzheimer's disease. The researchers contacted the participants every two years, assessing physical and mental functioning. By six years, 319 participants had developed dementia, including 221 with Alzheimer's disease. The participants whose physical function was higher at the start of the study were three times less likely to develop dementia than were those whose physical function was lower.
"Everyone had expected the earliest signs of dementia would be subtle cognitive changes," said Eric B. Larson, MD, MPH, director of Group Health Center for Health Studies. "We were surprised to find that physical changes can precede declines in thinking."
In the study, the first indicators of future dementia appeared to be problems with walking and balance. A weak handgrip may be a later sign of the development of dementia in older people. In a recent report the researchers found that when people exercised regularly, they were less likely to develop dementia, including Alzheimer's disease. The cause of this association was not clear, though. This newer study suggests a possible pathway: that regular exercise may help stave off dementia by improving and maintaining physical conditioning.
"These results suggest that in aging, there's a close link between the mind and body," said Larson. "Physical and mental performance may go hand in hand, and anything you can do to improve one is likely to improve the other." If people notice that they are starting to decline physically, he said, reengaging in physical activity may help them to stop or slow this decline - and reduce their risk of early cognitive worsening. On the other hand, he said, it is still possible for people who have physical constraints, even paralysis, to stay mentally alert and cognitively fit.
MEDICA.de; Source: Queen’s University Group Health Cooperative Center for Health Studies