Headlines often conflate associations into causation, essentially as click-bait. What does that mean?
My favorite example is “Ice Cream Causes Drowning”. No – I don’t mean the kids went swimming too soon after eating (that’s a myth, too, by the way). Drowning increases when more people go swimming. More people go swimming when it’s hot; more people eat ice cream when it’s hot, ergo – ice cream causes drowning. Duh --- NO! Association is not causation.
Here we have more steps equals less depression. But how do we know that the more depressed on is, the less likely they are to walk lots of steps? Meta-analyses group together lots of studies that may look at different questions, but have data that can be examined from a different angle. Opportunities to point to causation is extremely limited. Most of the articles these days are in this category, so be careful in the conclusions you draw.
What can we say? If you walk more, you’re less likely to be depressed. Does walking more decrease depressive symptoms? The answer to that is YES – just not from this meta-analysis.
FROM MEDSCAPE / BY ANUSHREE CHAPHALKAR
Can Walking More Steps Per Day Help Keep Depression Away?
TOPLINE:
Walking 7000 or more steps per day is associated with fewer depressive symptoms and a 31% lower risk for depression than taking fewer steps, a new meta-analysis shows.
METHODOLOGY:
Researchers conducted a systematic review and meta-analysis of 33 observational studies that included more than 96,000 adults aged 18-91 years.
Data were obtained from 27 cross-sectional and 6 longitudinal studies and from 5 major databases through May 2024.
Objectively measured daily step counts and depression data were collected via various assessment tools.
TAKEAWAY:
The number of daily steps had a significant inverse correlation with depressive symptoms in both cross-sectional (correlation coefficient [r], −0.12; 95% CI, −0.20 to −0.04) and panel studies (r, −0.17; 95% CI, −0.28 to −0.04).
Participants achieving 7000 steps per day or more showed a lower risk for depression than those achieving less than 7000 steps per day (risk ratio [RR], 0.69; 95% CI, 0.62-0.77).
An additional increase of 1000 steps per day was associated with a 9% lower risk for depression (RR, 0.91; 95% CI, 0.87-0.94).
Cross-sectional analysis showed that, compared with walking less than 5000 steps per day, walking 5000-7499 steps per day, 7500-9999 steps per day, and at least 10,000 steps per day were all significantly associated with fewer depressive symptoms (standardized mean difference, −0.17, −0.27, and −0.26, respectively).
IN PRACTICE:
"The objective measurement of daily steps may represent an inclusive and comprehensive approach to public health that has the potential to prevent depression. Small amounts of PA [physical activity] may be particularly relevant for specific populations, such as older adults and individuals with limited activities of daily living, for whom daily steps emerge as an accessible PA strategy," the investigators wrote.
SOURCE:
The study was led by Bruno Bizzozero-Peroni, PhD, Health and Social Research Center, Universidad de Castilla-La Mancha, Cuenca, Spain. It was published online December 16 in JAMA Network Open.
LIMITATIONS:
Reverse associations were possible, and causal inferences could not be made from the findings. In addition, the analysis showed substantial between-study heterogeneity in some pooled estimates, partially explained by differences in participant characteristics and step-counting devices. Most studies also lacked robust methods, potentially affecting result reliability, and the meta-analysis comparing high vs low daily step counts may have been susceptible to publication bias.
DISCLOSURES:
The study was funded by the University of Castilla-La Mancha, National Agency for Research and Innovation, Ministry of Economy and Competitiveness of Spain, Carlos III Health Institute, European Regional Development Fund, and European Union's Next Generation EU initiative. No conflicts of interest were reported.