Cycling Linked to 19% Lower Risk of Dementia in Large UK Biobank Study
Cycling and mixed cycling were associated with a reduced risk of all-cause dementia, including of young onset, as well as increased hippocampal volume.
Cycling and mixed-cycling travel modes reduced all-cause dementia risk by 19% compared with nonactive transportation in a prospective study of nearly 480,000 UK Biobank participants followed for more than 13 years. The protective effect proved strongest for young-onset dementia (YOD), with cycling participants showing a 40% lower risk of developing dementia before age 65 years.1
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The study, published in JAMA Network Open, also revealed that cycling correlated with larger hippocampal volumes on brain imaging and that genetic factors modified the protective benefits. Participants without the apolipoprotein E ε4 (APOE ε4) gene variant experienced greater protection from cycling than those carrying the Alzheimer disease (AD) risk allele.1
Researchers from Huazhong University of Science and Technology, in Wuhan, China and the University of Sydney in New South Wales, Australia, analyzed data from 479,723 Biobank participants aged 40 to 69 years recruited between 2006 and 2010. The cohort included 8,845 incident dementia cases during follow-up, comprising 528 YOD cases and 8,276 late-onset dementia (LOD) cases.1
The investigation addresses growing concerns about dementia's global burden, projected to increase from 55 million cases in 2019 to 139 million by 2050.2 YOD, though less common than LOD, carries particularly high care burdens and mortality rates.3 The 2024 Lancet Commission identified 14 modifiable risk factors responsible for approximately 45% of dementia cases, emphasizing physical activity during middle age as a key preventive measure.4 However, an estimated 1.4 billion adults worldwide fail to meet World Health Organization physical activity recommendations.5
Investigators categorized participants into 4 travel groups based on their most frequent non-work transportation in the preceding 4 weeks: nonactive (car, motor vehicle, or public transport), walking only, mixed-walking (combination of nonactive and walking), and cycling with mixed-cycling. The research team identified dementia cases through hospital records and death registries.
Cox proportional hazards regression models were adjusted for demographic factors, socioeconomic status, lifestyle variables, comorbidities, cognitive function, and genetic variables. Brain structural analysis included gray matter volume regions from MRI data in 44,801 participants.1
Walking, Driving, Brain Volume, Genetics
Additional findings suggested protective effects of mixed-walking modes (combination of nonactive and walking), which reduced all-cause dementia risk by 6% (HR 0.94, 95% CI 0.89-0.98). However, walking alone showed no significant protection against all-cause dementia and actually correlated with a 14% increased AD risk (HR 1.14, 95% CI 1.01-1.29), while cycling maintained its protective effect against AD with a 22% risk reduction (HR 0.78, 95% CI 0.66-0.92).
Interestingly, car or motor vehicle use carried lower dementia risks than public transportation alone, with participants showing a 22% lower all-cause dementia risk (HR 0.78, 95% CI 0.72-0.85) compared with public transport users, potentially reflecting the cognitive demands of driving versus passive transportation.1
Brain imaging analysis revealed significant associations between cycling and increased gray matter volumes in 10 brain regions. Cycling correlated specifically with higher hippocampal volume (β = 0.05, 95% CI 0.02-0.08), a brain region critical for memory formation and early affected in Alzheimer's disease.
Genetic interaction analysis revealed that APOE ε4 status significantly modified the relationship between travel modes and dementia risk. Among cycling participants without APOE ε4, all-cause dementia risk decreased by 26% (HR 0.74, 95% CI 0.63-0.87), while APOE ε4 carriers experienced only a 12% non-significant reduction (HR 0.88, 95% CI 0.76-1.02).1
The authors acknowledge several limitations to the study, including that the low incidence of YOD restricted statistical power for subgroup analyses. Self-reported travel mode data may have introduced measurement errors, and the study did not capture long-term travel pattern changes. The cohort's limited racial and ethnic diversity (over 85% European ancestry) limits generalizability, and heterogeneous clinical presentations may have affected diagnostic accuracy.1
Even with those limitations, the authors are confident in the contribution of the study to a better understanding of the role of specific physical activity in prevention of cognitive decline. "Our findings suggest that promoting active travel strategies, particularly cycling, may be associated with lower dementia risk among middle-aged and older adults, which carries substantial public health benefits by encouraging accessible, sustainable practices for cognitive health preservation,” they concluded.1
