The walking speed of 45 year olds -- particularly their fastest walking speed without running -- is related to the ageing process undergone by their brains and bodies, according to a study.
The researchers, including those from Duke University in the US, found that slower walkers have "accelerated ageing" on a 19-measure scale, and their lungs, teeth, and immune systems tended to be less fit than the people who walked faster.
The study, published in the journal JAMA Network Open, noted that the ageing effect was seen in 45-year-old people, not the geriatric patients who are usually assessed with such measures.
Neurocognitive testing done by the researchers revealed that these individuals, taken as children, could predict who would become the slower walkers.
According to the researchers, people's scores on IQ, understanding language, frustration tolerance, motor skills, and emotional control at age three predicted their walking speeds at age 45.
"Doctors know that slow walkers in their seventies and eighties tend to die sooner than fast walkers their same age," said senior author of the study Terrie E. Moffitt of Duke University.
But the study, Moffitt added, covered the period from the preschool years to midlife, revealing that a slow walk is a problem sign decades before old age.
The researchers used data from a long-term study of nearly 1,000 people who were born during a single year in Dunedin, New Zealand.
The 904 participants in the current study were tested, quizzed and measured their entire lives, mostly recently from April 2017 to April 2019 at age 45.
During their most recent assessment, MRI scans showed that the slower walkers tended to have lower total brain volume, lower mean cortical thickness, less brain surface area and higher incidence of white matter "hyperintensities," small lesions associated with small vessel disease of the brain, the study noted.
Their brains appeared somewhat older, the researchers said.
The slower walkers, the study noted, also looked older to a panel of eight screeners who assessed each participant's 'facial age' from a photograph.
While gait speed has long been used as a measure of health and ageing in geriatric patients, the new study observed the same effects in relatively young study subjects.
"It's a shame we don't have gait speed and brain imaging for them as children," said lead author of the study Line J.H Rasmussen of Duke University.
Some differences in health and cognition may be tied to lifestyle choices made by the individuals, the researchers said.
But according to the study, there are already signs in early life of who would become the slowest walkers.
"We may have a chance here to see who's going to do better health-wise in later life," Rasmussen said.
