"In this cohort study of 479 723 participants with over 13 years of follow-up, an active travel mode, particularly cycling and mixed-cycling, was associated with a lower incidence of all-cause dementia."
That’s from a recent study by Hou, et al. The authors are affiliated with Huazhong University in Wuhan (yes, THAT Wuhan) and the University of Sydney, Australia. The data are from the UK Biobank and the participants
are from England, Scotland, and Wales.
Active
Travel Mode and Incident Dementia and Brain Structure | Neurology | JAMA Network Open | JAMA Network
Here’s how the groups were defined:
Travel mode data were obtained from touchscreen questionnaires. Baseline assessments used responses to the question “In the last 4 weeks, which forms of transport have you used most often to get about (not
including any journeys to and from work)?” Respondents could select 1 or more of the following options: car or motor vehicle, walking, public transporter, and cycle. The exposure variable was categorized into the following 4 groups: nonactive (car or motor
vehicle or public transporter), walking, mixed-walking (combination of nonactive and walking), and cycling and mixed-cycling (cycling combined with other modes) modes.
As is usual with such studies, several models were estimated, which used different covariates (see table). Cycling and mixed-cycling had a relative risk of .72 to .81 in the 3 models shown. This means that
for every 100 people in the Nonactive group who developed dementia, only 72 to 81 people in the cycling and mixed-cycling group developed dementia.
While the use of a wide variety of covariates indicates this is likely a robust finding, it is still subject to the usual caveats from such studies: these are self-selected groups and may differ in other ways
not measured by the covariates. In addition, travel mode was assessed once, at the beginning of the 13 year study. Still, this is encouraging.