LONDON — How fast you walk in your elder years may be more than just a sign of your mobility. It can indicate brain health, too. A new study finds that older adults who walk slowly are more likely to develop dementia.

Researchers from the University College London and University of Nottingham examined data from 3,932 adults over 60 who had participated in the English Longitudinal Study of Aging. The authors recorded the participants’ walking speeds on two occasions in 2002-2003 and in 2004-2005. They then checked to see if those individuals had been diagnosed with dementia during annual follow-up assessments between 2006 and 2015.

After comparing results, the authors noticed an uptick in dementia cases among participants who were measured as slower walkers. This was especially true for individuals who showed a faster drop in their walking speeds between testing periods. That is, those who had the most significant declines in speed over the two years when they were measured proved to be at a greater risk for the condition.

Interestingly, the researchers also noticed it wasn’t just the speed of one’s pace that indicated dementia risk. They found that participants who were slower in their thought process when it came to decision-making during the testing periods were also more prone to developing the condition later on. And just like those who showed a greater decline in walking speed during the two-year testing period were at a higher risk, so too were individuals who also had faster declines in their cognitive abilities.

Despite the findings, the authors couldn’t conclude that a decline in walking speed was necessarily connected to a decline in cognitive functioning.

According to the World Health Organization, it’s estimated that 47 million people across the globe suffer from dementia. That number is expected to balloon to 75 million by 2030.

The full study was published March 6, 2018 in the Journal of the American Geriatrics Society.