A recent study published on JAMA Network Open revealed that regular cycling in middle age may reduce the risk of developing dementia. Conducted by researchers from Huazhong University of Science and Technology in Wuhan, China, and the University of Sydney in New South Wales, Australia, the study analyzed health records of 479,723 participants with an average age of approximately 56 years.
The researchers found that individuals who cycled regularly had a 19% lower risk of all-cause dementia compared to those who used non-active modes of transportation like driving or public transport. The protective effect was even stronger for young-onset dementia (before age 65), with frequent cyclists showing a 40% lower risk.
"Cycling requires higher cognitive engagement while moving, and all of this helps preserve hippocampal volume," said Dr. Liangkai Chen from Huazhong University of Science and Technology, who led the study. The hippocampus is a critical brain region associated with memory and learning abilities, often affected early in Alzheimer's disease.
Over an average follow-up period of 13.1 years, the study recorded 8,845 cases of dementia among the participants, including 528 cases of young-onset dementia and 4,000 cases of Alzheimer's disease. Participants were divided into groups based on their preferred mode of transportation, excluding commutes to and from work: cyclists, walkers, mixed walkers, mixed cyclists, and those using cars or public transport.
Neuroimaging analyses of 44,801 participants revealed that cyclists had a larger volume of gray matter in their brains, particularly in the hippocampus region. This increase in hippocampal volume aligns with previous studies linking spatial navigation skills to brain volume. "Cycling exercise can help increase blood flow to the brain, reduce inflammation, and stimulate neurogenesis," Chen explained.
The study also found that even individuals carrying the APOE ε4 gene, a genetic risk factor for Alzheimer's disease, experienced a protective effect from cycling, though the benefit was less pronounced. Participants without the gene saw a 26% reduction in dementia risk with regular cycling, while those with the gene experienced a 12% reduction.
The researchers accounted for factors that could influence dementia risk, including age, gender, education, smoking, alcohol consumption, and overall health. They emphasized that promoting active transportation strategies, especially cycling, could bring public health benefits by encouraging accessible and sustainable practices for preserving cognitive health among middle-aged and older adults.
"Dementia has emerged as a leading contributor to dependence and disability among older adults," the researchers wrote. "Our findings suggest an association between active travel mode and incident dementia and brain structure."
However, the study acknowledged several limitations, including reliance on self-reported data, which may introduce measurement errors. Additionally, more than 85% of participants were of European descent, so it is uncertain whether the findings apply to all populations.
Despite these limitations, the authors are confident in the contribution of the study to a better understanding of the role of specific physical activity in the prevention of cognitive decline. They advocated for further research to explore how cycling protects the brain and to investigate its effects over longer durations.
The findings came at a crucial time, as dementia is a growing issue worldwide. Projections indicate that global cases could increase from 55 million in 2019 to 139 million by 2050. The study underscored the urgent need to identify effective methods to reduce dementia risk.
"If you are able to ride a bike, do it. If not, use your feet," the researchers recommended. Incorporating cycling into daily routines not only promotes individual health but also offers a sustainable and low-cost mental health protection tool, especially for older individuals.
Written with the help of a news-analysis system.