Walking certain distances can proportionally reduce the risk of dementia according to new international research.
The study, published September 6th in JAMA Nuerology, found that taking 9800 steps a day appeared to provide the optimal reduction of dementia risk, but as few as 3800 steps a day was still associated with a 25% lower incidence of the condition.
Researchers used data from the UK Biobank, collected between February 2013 to December 2015, to monitor some 78,000 adults aged 40 – 79 years who were free of cardiovascular disease, cancer, or dementia at the time of recruitment.
Participants were instructed to wear an accelerometer on their dominant wrist 24 hours a day, 7 days a week, to measure their physical activity.
A total of 866 participants had developed dementia by the time of follow-up, conducted nearly seven years later in October 2021, with incident dementia data (fatal and nonfatal) obtained from inpatient hospitalization or primary care records, or registered as the underlying cause of death.
Lead author, Dr Borja del Pozo Cruz, from the Department of Sport Sciences and Clinical Biomechanics at the University of Southern Denmark’s Centre for Active and Healthy Ageing, said that a higher number of steps was associated with lower risk of all-cause dementia.
“[Even though] there was no minimal threshold for the beneficial association of step counts with incident dementia, we found nonlinear associations for daily steps, wherein the optimal dose was 9826 steps, and the minimal dose was 3826 steps,” Dr del Pozo Cruz said.
“Other studies have found 4400 steps to be associated with mortality outcomes and this finding suggests that population-wide dementia prevention might be improved by shifting away from the least-active end of the step-count distributions.
“Unlike previous studies investigating mortality outcomes, our analyses highlight the importance of stepping intensity for preventing dementia, with both purposeful steps and peak 30-minute cadence (an indicator of overall best natural effort in a free-living environment) associated with lower risks of dementia.”
Dr del Pozo Cruz explained that the team identified walking activities using an accelerometer-based activity machine learning scheme with cadence-based stepping metrics reflective of pace and intensity under free-living conditions.
For incidental steps, defined as fewer than 40 steps per minute (such as indoor walking from one room to another), the optimal dose was 3677 steps; for purposeful steps, defined as 40 or more steps per minute, the optimal dose was 6315 steps; and for peak 30-minute cadence (the average steps per minute recorded for the 30 most active minutes in a day), the optimal dose was 112 steps per minute.
“Step count–based recommendations have the advantage of being easy to communicate, interpret, and measure, and may be particularly relevant for people who accumulate their physical activity in an unstructured manner,” the authors concluded.
“For such individuals, it may be otherwise challenging to track physical activity or determine whether they are sufficiently active relative to current minute- and intensity-based physical activity guidelines (150 to 300 minutes per week of moderate to vigorous physical activity).
“Therefore, step-based recommendations could provide informative supplementary information to the current physical activity guidelines.”