Researchers had expected the first signs of Alzheimer's disease to be mental. But after following nearly 2,300 elderly people for six years, they found that those who were physically more able were up to three times less likely to develop the condition.
Among those who did get dementia, the first signs were problems walking and with balance generally, followed by a weak handgrip.
The research was conducted at Washington University and the Group Health Center in Seattle, Wash. Dr. Eric Larson, the center's director, said, "Everyone had expected the earliest signs of dementia would be subtle cognitive changes. We were surprised to find that physical changes can precede declines in thinking." He added that what is considered a brain disease may be intimately connected to physical fitness.
The study, which was reported in the Archives of Internal Medicine journal recently, looked at 2,288 people who were aged 65 and older, none of whom showed any signs of dementia.
The researchers contacted them every two years, assessing their physical and mental functioning. After six years, some 319 people in the group had developed dementia, including 221 with Alzheimer's disease, which is a type of dementia.
