Fast Walkers Have Higher IQ and Larger Brains Than Slow Walkers
Introduction
It’s commonly believed that physical health and cognitive health are interconnected, but recent studies are shedding light on how closely these domains are tied, especially as people age. A fascinating study from the Dunedin Multidisciplinary Health and Development Study cohort reveals that middle-aged individuals who walk at a faster pace tend to have higher IQs, larger brain volumes, and even appear biologically younger than their slower-walking peers. These findings offer insights into how physical fitness can mirror and influence brain health and cognitive abilities, emphasizing gait speed as a potential predictor of long-term cognitive health.
The Study: Purpose and Methodology
The researchers examined participants from the Dunedin Study, a long-term cohort study following individuals from birth through adulthood. When participants reached the age of 45, researchers assessed their gait speed, brain health, and cognitive function to explore the potential links between physical and cognitive aging. The study involved 904 participants and measured gait speed under three conditions: normal walking pace, dual-task walking (where participants performed a mental task while walking), and maximum walking speed. By observing gait under these varied conditions, researchers aimed to gain a comprehensive understanding of each participant's walking efficiency and stability.
In addition to gait measurements, participants underwent brain imaging to assess brain volume and cortical thickness, both critical markers of brain health. Cognitive tests were administered to evaluate IQ, verbal comprehension, processing speed, and memory, providing a robust view of each participant’s cognitive profile. To account for the possible influence of lifelong factors, the study also considered cognitive scores from childhood, allowing researchers to examine whether gait speed in midlife correlates with cognitive performance across the lifespan.
Key Findings: The Link Between Gait Speed, IQ, and Brain Health
The study found several noteworthy associations between gait speed, IQ, and brain structure, illustrating that physical activity levels and cognitive health are not isolated aspects of well-being. Here are some of the most significant findings:
- Higher IQ in Faster Walkers: Faster walkers had consistently higher IQ scores compared to slower walkers. This association was evident not only in midlife but was also traceable to cognitive tests administered during childhood. Thus, gait speed in middle age appears to correlate with a lifetime of cognitive performance.
- Greater Brain Volume and Cortical Thickness: Faster walkers displayed larger brain volumes and greater cortical thickness compared to their slower counterparts. Since reduced brain volume and cortical thinning are often associated with aging and neurodegenerative diseases, these findings suggest that faster walkers may experience healthier brain aging.
- Reduced White Matter Hyperintensities: Slower walkers exhibited more white matter hyperintensities, or small lesions in the brain’s white matter, which are often linked to cognitive decline and increased stroke risk. Faster walkers, with fewer of these lesions, demonstrated healthier white matter integrity.
- Slower Walkers Show Signs of Accelerated Aging: In addition to cognitive markers, the study found that slower walkers exhibited multiple signs of accelerated aging. For instance, they appeared physically older, displayed greater biological age differences, and had poorer physical health scores compared to faster walkers. This suggests that gait speed may be a useful indicator of overall biological aging.
The Science Behind the Link: Why Does Walking Speed Reflect Cognitive Health?
Understanding why faster walking is associated with higher IQ and larger brain volumes involves examining the brain-body connection. Gait is a complex physical activity that requires coordination, balance, motor control, and cognitive processing. Engaging multiple brain regions, walking speed can thus be affected by the health and functionality of these neural networks. Faster walkers may have better-preserved motor and cognitive networks, enabling them to move more efficiently while also demonstrating higher cognitive function.
Furthermore, physical activity has long been associated with brain health. Regular physical exercise increases blood flow to the brain, supports neurogenesis (the formation of new neurons), and improves brain plasticity. Over time, these benefits can contribute to larger brain volumes, reduced cortical thinning, and the preservation of cognitive functions. Conversely, reduced mobility and slower walking may signal the beginning of cognitive and physical decline, making gait speed an accessible and measurable early marker of aging.
Implications for IQ and Aging
The implications of these findings are significant, suggesting that monitoring gait speed could become a routine part of assessing cognitive health, especially in middle age. If walking speed in midlife reflects lifelong brain health and cognitive abilities, it could serve as an early warning sign for those at risk of cognitive decline or other age-related diseases. Doctors and health practitioners could monitor gait speed as a non-invasive and cost-effective way to gauge patients’ brain health and aging trajectory.
These findings also suggest potential interventions. For instance, promoting physical activity and maintaining an active lifestyle could help support both physical and cognitive health as people age. Encouraging patients to engage in regular exercise, especially activities that combine cardiovascular benefits with motor skills, could help slow down the aging process, both physically and mentally. Since IQ and cognitive ability appear to be linked to physical vitality, fitness could play an important role in preserving mental acuity as we age.
Limitations and Future Research
While the findings provide strong support for a link between gait speed, brain health, and cognitive performance, more research is needed to fully understand the relationship. The study involved participants from a specific cohort in New Zealand, which may limit the generalizability of the findings to other populations. Future research involving more diverse populations could help determine whether these findings hold across different ethnicities, regions, and socioeconomic groups.
Additionally, while the study demonstrates correlation, it cannot conclusively prove causation. Further studies could explore whether interventions aimed at increasing gait speed, such as physical therapy or exercise programs, result in measurable improvements in cognitive function or brain structure. Understanding whether enhancing physical health can directly impact cognitive resilience could open up new avenues for age-related cognitive care and disease prevention.
Conclusion
The study from the Dunedin Multidisciplinary Health and Development Study cohort provides valuable insights into the relationship between gait speed, brain health, and IQ. Faster walkers not only perform better cognitively but also exhibit larger brain volumes and less biological aging, underscoring the link between physical and mental health. While the exact mechanisms underlying this connection are still being explored, the findings suggest that physical fitness and cognitive resilience are intertwined throughout life.
As the field of cognitive health continues to evolve, these findings highlight the potential of gait speed as a valuable biomarker for assessing cognitive and physical aging. For anyone interested in understanding their own cognitive abilities, taking a comprehensive IQ test can offer insights. Visit our IQ articles section for more resources on intelligence, cognitive health, and the fascinating connections between the mind and body.