Walking slowly could be an early indicator of Alzheimer's disease in the elderly, according to a new study led by researchers from the University Hospital Toulouse in France. The researchers studied 128 elderly people with an average age of 76 who had memory problems and were at high risk for dementia.

Positron emission tomography (PET) brain scans showed that 48 percent of the study participants had thick deposits of amyloid plaques. These plaques are made up of beta amyloid, a protein that is associated with the development of dementia and Alzheimer's disease. When tested for their thinking and memory skills, 46 percent of study participants showed mild cognitive impairment.

The researchers also investigated the walking speed of the study participants. They found that those who walked slowly had more deposits of amyloid in the brain, particularly in the putamen, a region involved in motor function.

Taking into account the presence or absence of amyloid deposits, the researchers found that amyloid deposits caused a 9 percent difference in the participants' walking speeds. This result remained consistent even when factors like age, memory problems and education were considered.

"It's possible that having subtle walking disturbances in addition to memory concerns may signal Alzheimer's disease, even before people show any clinical symptoms," study author Natalia del Campo said in a press release.

However, del Campo emphasized that the study merely showed an association between walking speed and beta amyloid buildup, not a cause-and-effect relationship.

The study was published Dec. 2 in the journal Neurology.