An international team of researchers have found that slower walking speed or a faster decline in walking speeds among older adults put them at high risk for dementia too, a problem affecting nearly 47 million people globally.

Older adults with slower walking speeds seem to have a greater risk of dementia than those with faster walking speeds, researchers have found. The findings, led by Ruth A. Hackett, from the University College London, showed that people who experienced a faster decline in walking speed over a two-year period were also at higher risk for dementia. People who had a poorer ability to think and make decisions, and those whose cognitive (thinking) abilities declined more quickly were also more likely to be diagnosed with dementia.

As of 2015, nearly 47 million people around the world had dementia, a memory problem significant enough to affect your ability to carry out your usual tasks. The most common cause of dementia is Alzheimer's disease, but other forms exist, too. For the study, published in the Journal of the American Geriatrics Society, an international team of researchers included nearly 4,000 older adults aged 60 and above to learn more about changes in walking speed, changes in the ability to think and make decisions, and dementia.

They assessed participants' walking speed on two occasions in 2002-2003 and in 2004-2005, and whether or not the participants developed dementia after the tests from 2006-2015. Then, they compared the people who had developed dementia with those who had not. However, changes in walking speed and changes in an older adult's ability to think and make decisions do not necessarily work together to affect the risk of developing dementia, the researchers noted.