Summary: The ability to walk and talk in two tasks begins to decline around the age of 55. This decline is due to changes in cognition and underlying brain function rather than physical changes associated with aging.
Source: Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research
Walking is a complex task that is most commonly performed while performing other tasks such as talking, reading signs, or making decisions.
For most people after the age of 65, such “double work” impairs walking performance and may even cause instability. Interestingly, older adults who are more affected by dual work are at greater risk of adverse health outcomes, including falls and dementia.
A new study was published in Lancet Healthy Longevity have reported that the ability to double walk begins to decline at age 55, up to ten years before “old age,” traditionally defined as the 65-year threshold.
Furthermore, this simultaneous decline in walking and speaking ability was not found to be due to physical functions, but instead to changes in cognition and underlying brain activity.
“Our results suggest that poor dual walking performance in middle age may be indicative of accelerated brain aging or otherwise a pre-symptomatic neurodegenerative state,” said lead author Junhong Zhou, Ph.D, Assistant Scientist I, Hinda. and the Arthur Marcus Institute for Aging Research.
“We evaluated a large group of people aged 40 to 64 who are part of a study called the Barcelona Brain Health Initiative (BBHI). We found that the ability to walk in normal, quiet conditions remained relatively stable across this age group.
“However, even in this relatively healthy cohort, when we asked participants to walk while performing a mental arithmetic task, we were able to detect subtle but important changes in gait from the middle of the sixth decade.”
“This means that a simple dual-task walking test, which examines the brain’s ability to perform two tasks at the same time, can reveal early, age-related changes in brain function that may indicate an increased risk of developing dementia later in life,” said Zhou.
The paper was the result of a unique collaboration between researchers from the Hinda and Arthur Marcus Institute at Hebrew SeniorLife in Boston and the Guttmann Institute in Barcelona, Spain, where the population-based Barcelona Brain Health Initiative (BBHI) is being implemented.
BBHI’s principal investigator is Professor David Batres-Faz of the University of Barcelona and Dr. Alvaro Pascual-Leone, Medical Director of the Deanna and Sidney Wolk Center for Memory Health and Senior Scientist at the Hinda and Arthur Marcus Institute for Aging Research at Hebrew SeniorLife, who serves as BBHI’s Scientific as a leader.
“Compared to quiet walking, walking in dual-task conditions increases the motor control system because the two tasks (for example, walking and mental computation) have to compete for shared resources in the brain. We believe that the ability to handle this stress and maintain adequate performance in both tasks is a critical brain function that tends to decline with age.
“Our study is important because it has found that changes in this type of brain resilience occur much earlier than previously thought,” said Zhou.
“We now have a clearer picture of age-related changes in gait control and how this relates to cognitive and brain health,” said Zhou.
“Importantly, however, although we found that dual-task walking decreased with age in the entire cohort, not all study participants fit this description.”
“For example, we found that some of the participants over 60 who completed the dual-task test, as well as participants 50 or younger. This means that dual-task walking performance does not necessarily decline as we age, and that some people appear to be more resistant to the effects of aging.
“We hope that our study will encourage future research efforts to identify lifestyle and other modifiable factors that support maintenance of dual-task performance into old age, as well as interventions targeting these factors.”
Observations
996 people were recruited for the BBHI study from 5 May 2018 to 7 July 2020, of which 640 participants completed walking and cognitive assessments during this period (an average of 24 days [SD 34] between the first and second visit) and were included in the analysis (342 men and 298 women). Non-linear associations were found between age and the performance of the two tasks.
From 54 years, DTC step time (β = 0.27 [95% CI 0·11 to 0·36]; p<0·0001) and step time variation (0.24 [0·08 to 0·32]; p=0·0006) increased with age. In subjects aged 54 years or older, impaired global cognitive functioning was correlated with a longer step in DTC (β=–0.27 [–0·38 to –0·11]; p=0·0006) and added DTC to stride time variation (β=–0.19 [–0·28 to –0·08]; p=0·0002).
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Source: Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research
Contact: Press Office – Hebrew SeniorLife Hinda and Arthur Marcus Institute for Aging Research
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Original research: Open access.
“Age-related influence of cognitive functions on dual-task walking in middle-aged adults in Spain: findings from a population-based study” Junhong Zhou et al. Lancet Healthy Longevity
Abstract
Age-related influence of cognitive function on dual-task walking in middle-aged adults in Spain: findings from a population-based study
Background
Poor dual-task walking performance is associated with fall risk and cognitive decline in adults over 65 years of age. When and why dual-task walking ability begins to decline is not known. The aim of this study was to characterize the relationships between age, dual-task walking, and cognitive function in middle age (ie, 40–64 years).
methods
We performed a secondary analysis of data from community-dwelling adults aged 40–64 years who participated in the Barcelona Brain Health Initiative (BBHI), an ongoing longitudinal cohort study in Barcelona, Spain. Participants were eligible if they were able to walk independently without assistance and had completed assessment of both gait and cognition at the time of analysis, and were ineligible if they did not understand the study protocol, had clinically diagnosed neurological or psychiatric conditions, and were cognitive. debilitated or has pain in the lower limbs, osteoarthritis or rheumatoid arthritis that can cause abnormal walking. Step time and step time variability were measured under conditions of one task (i.e. walking only) and two tasks (i.e. walking while performing serial subtraction). Dual-task cost (DTC; percentage increase in step scores from single-task conditions to dual-task conditions) was calculated for each walking outcome and used as the primary measure in the analyses. Global cognitive functions and five cognitive domain composite scores were derived from neuropsychological tests. We used locally estimated scatterplot smoothing to characterize the relationship between age and dual-task walking and structural equation modeling to examine whether cognitive functioning mediated the association between observed biological age and dual-tasking.
Observations
996 people were recruited for the BBHI study from 5 May 2018 to 7 July 2020, of which 640 participants completed walking and cognitive assessments during this period (an average of 24 days [SD 34] between the first and second visit) and were included in our analysis (342 men and 298 women). Non-linear associations were found between age and the performance of the two tasks. From 54 years, DTC step time (β = 0.27 [95% CI 0·11 to 0·36]; p<0·0001) and step time variation (0.24 [0·08 to 0·32]; p=0·0006) increased with age. In subjects aged 54 years or older, impaired global cognitive functioning was correlated with a longer step in DTC (β=–0.27 [–0·38 to –0·11]; p=0·0006) and added DTC to stride time variation (β=–0.19 [–0·28 to –0·08]; p=0·0002).
Interpretation
Dual-task walking performance begins to decline in the sixth decade of life, and after this, between-individual variance in cognition explains a significant portion of dual-task performance.
Funding
La Caixa Foundation, Institut Guttmann and Fundació Abertis.