A study published in The Lancet that analysed 74 investigations with more than 4.2 million participants found significant differences in how different types of physical activity affect the risk of dementia and Alzheimer's. Recreational physical activity was associated with approximately 24% lower dementia risk, while work-related activity showed opposite results.
According to the research, physical activity at work was linked to a 20% increase in dementia risk. Active commuting to work, such as cycling or walking, also showed a 10% increase in risk. Experts caution, however, that these results do not mean that moving the body at work directly causes dementia.
The researchers noted that multiple contextual factors explain these associations. Physically demanding jobs frequently entail complex socioeconomic and environmental conditions, including chronic stress, exposure to noise and toxins, lower incomes, lower educational levels and higher incidence of injuries. These elements, and not the movement itself, apparently raise the risk of cognitive decline.
The finding aligns with previous research. A 2022 meta-analysis in the British Journal of Sports Medicine concluded that physical activity in general acts as a protective factor against Alzheimer's and vascular dementia, although it warned about the need for interpretative caution. Other large studies, such as the Copenhagen Male Study and UK Biobank analyses, have yielded varied results depending on the population studied.
The World Health Organization recommends not avoiding occupational physical activity and incorporates all movement, from structured sport to household tasks, in a broader preventive approach that also includes control of hypertension, diabetes, obesity, smoking and hearing health.
