Slow walkers more likely to get sick when old, study finds

Walking slowly could be a sign you’re more likely to get sick in later life, according to new research.

A simple test to measure the speed someone walks could predict their chance of getting diseases like Alzheimer’s decades before symptoms develop, scientists say.

Researchers found 45-year-olds who naturally walked slowly had brains and bodies that showed signs of “accelerated ageing” on a 19-measure scale. Their lungs, teeth and immune system were all in worse shape than people of the same age who walked faster.

They also had lower total brain volume, less brain surface area and more small lesions in the brain, which is normally indicative of someone older.

Slower walkers also looked older in the eyes of a panel of eight people who assessed each participant’s “facial age” from a photograph.

“The thing that’s really striking is that this is in 45-year-old people, not the geriatric patients who are usually assessed with such measures,” said lead researcher Line JH Rasmussen, a post-doctoral researcher at America’s prestigious Duke University.

Scientists could work out how fast someone would walk in middle-age by looking at their brains when they were just three years old. Scores on their IQs, their ability to understand language, motor skills and emotional control could predict their walking speed at 45, according to the paper published in Jama Network Open journal.

There was a difference of 12 IQ points on average between children who grew up to be slowest (with a mean gait speed of 1.21 metres per second) and fastest (with a mean gait speed of 1.75 metres per second).

Scientists believe this is because the ability to walk depends on the interplay of many organ systems. They also believe cognitive functions like memory and walking speed could be associated.

“A person’s walking speed depends on the function of all these systems working smoothly together, and reduced walking speed can be a sign of advanced ageing and deteriorating function of these organ systems,” said senior author Terrie E Moffitt from Duke University and King’s College London. “This inexpensive and quick test tells us a lot about their inner health, and how fast their organ systems and brains are ageing towards later diseases.”

Dr Moffitt added: “Doctors know that slow walkers in their seventies and eighties tend to die sooner than fast walkers their same age. But this study covered the period from the preschool years to midlife, and found that a slow walk is a problem sign decades before old age.”

The research is based on a long-term study of 904 people born during the same year in Dunedin in New Zealand. Participants have been studied their whole lives, with the most recent research between April 2017 and April 2019 when participants were 45.

Researchers used MRI (magnetic resonance imaging) scans to look at what was happening in the brain.

Professor Stephanie Studenski from the University of Pittsburgh, who was not involved in the study, said that testing gait speed could be an inexpensive indicator of wellbeing across adulthood.

She said: “The study confirms that a subset of persons in their 40s already show indicators of future health challenges and are already ageing more quickly than their peers. Furthermore, this study suggests that unknown factors that had already affected 3-year-old children also influenced their health and function 40 years later.”

Some of the differences in health and cognition may be linked to an individual’s life choices, scientists say.

Professor Studenski commented that some of the markers of childhood brain health could have been influenced by other important factors such as anxiety, sensory functions or how well the child felt on the day of testing.

“Although the associations persisted after accounting for childhood socioeconomic status, there are many things we do not know about these children, including their prenatal care, birth weight, childhood illnesses, sensory function, home situations, or environmental risks,” she said.