Higher Daily Step Count and Intensity Optimal for Reducing Dementia Risk

The number of steps walked per day may affect dementia risk, according study findings published in JAMA Neurology.

Current evidence suggests that walking between 6000 and 8000 steps per day may reduce risk for all-cause mortality. In addition, studies have evaluated the relationship between daily steps and cardiovascular mortality, cancer mortality, and incident diabetes, but the relationship between step-based physical activity and dementia have not been evaluated.

Researchers from the University of Southern Denmark and The University of Sydney in Australia sourced data for this study from the UK Biobank. Eligible participants were contacted via email and 78,430 individuals aged 40-79 years ultimately participated in this study by wearing an activity monitor for a minimum of 3 days for at least 16 hours per day. Daily steps were associated with incident dementia data obtained through linked medical records.

The study population comprised 55.3% women, aged mean 61.1 (standard deviation [SD], 7.9) years, 96.7% were White, 55.3% had a university degree, Townsend deprivation index score was -1.77 (SD, 2.79), and total steps per day was 8040.59 (SD, 4932.97). Stratified by tertile, tertile 1 took 1540 to <5386 steps (n=26,149), tertile 2 took 5386 to <8821 steps (n=26,151), and tertile 3 took ³8821 steps (n=26,150) per day. The lowest tertile included older, more educated individuals who consumed fewer fruits and vegetables.

During a median follow-up of 6.9 years, 866 individuals were diagnosed with dementia.

A nonlinear relationship between daily steps and dementia risk was observed, in which the optimal dose was 9826 steps with a minimum of 3826 steps (hazard ratio [HR], 0.75; 95% CI, 0.67-0.83). Stratified by type of step, the optimal dose of incidental steps was 3677 (HR, 0.58; 95% CI, 0.44-0.72), and the optimal dose of purposeful steps was 6315 (HR, 0.43; 95% CI, 0.32-0.58).

The peak 30-minute cadence was 112 steps per minute (HR, 0.38; 95% CI, 0.24-0.60).

Similar findings were observed when individuals who developed dementia within the first 2 years of follow-up were removed or after adjusting for relevant biomarkers for dementia.

This study was limited by the lack of diversity among the study population. It remains unclear whether these findings may be generalizable for a more diverse population.

These data indicated that along with cardiovascular and metabolic health, daily steps may also be associated with neurologic health outcomes. This study found that approximately 9800 daily steps may decrease risk for dementia. “Future guidelines for dementia prevention may capitalize on the results of this study to promote step-based recommendations,” the researchers concluded.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.