7 Healthcast: New warning signs for Alzheimer's

NEW YORK, N.Y. (NBC) -- Small changes in the way a person walks may be early signals of memory declines in the brain. Dr. Nancy Snyderman reports.

Although some walking difficulty is a common part of the aging process, researchers at the Basel Mobility Center in Basel, Switzerland said pronounced slowing of walking pace or a more variable stride could indicate early signs of cognitive decline.

Their study of more than 11-hundred elderly adults showed those with Alzheimer’s disease walked much slower than those with mild cognitive impairment, who also walked slower than healthy adults.

It may sound surprising but new research presented today suggests something as simple as the way we walk could be an early warning sign of mental decline.

“Subtle motor changes or gait speed changes that you can detect may be a warning system to kind of let you know there might be some abnormal pathology in the brain that could lead to cognitive decline later on,” said Dr. Lisa Silbert of the Oregon Health and Science University.

Graphic researchers looked at the relationship between brain function and the gait of a person's walk, measuring things like speed, rhythm and stride.

While changes in walking are expected with age, and slowing down is not necessarily a cause for concern, people with Alzheimer’s, and those with less advanced cognitive impairment, walked slower than people with normal mental function.

“We may be able to catch cognitive decline at an earlier stage by focusing in addition to their thinking abilities um to their walking abilities and their motor abilities,” said Dr. Silbert.

It's been generally accepted that regular physical exercise can improve health as we age but now, studies are looking at which types of activities are most effective, and why.

In another study presented at the Alzheimer’s Association’s Annual Conference, scientists at the University of Pittsburgh found evidence that suggests walking could help decrease known risk factors for Alzheimer’s more than other types of exercise. A part of the brain responsible for regulating memory, emotion and learning characteristically shrinks in patients with Alzheimer’s but, in people who exercised aerobically by walking regularly for a year it grew, compared to those who simply stretched and toned. Experts said the findings are evidence that lifestyle can impact the brain even as we age.

“Very clearly the best thing that you can do for your brain all throughout your life and especially as you age is physical exercise,” said Dr. Samuel Gandy of the Mount Sinai School of Medicine.

With more research, understanding the relationships between exercise, motor skills and mental function could help doctors diagnose, treat and monitor dementia.