People who bike or walk to work or school may be at lower risk of mental and physical health problems than those who don’t rely on these means, finds a large, long-term study published in an open access journal. BMJ Public Health.
While both types of active commuting offered health benefits, the greatest health benefits were seen for bicycle commuters, who reduced their risk of death from any cause by 47%.
Active travel is considered one of the most practical and sustainable ways to increase daily physical activity, and there is growing evidence supporting the associated health benefits, the researchers note.
However, existing evidence is hampered by short surveillance periods, narrow age ranges and limited health outcomes, the researchers added.
To remedy these shortcomings, the researchers used nationally representative data from the Scottish Longitudinal Study (SLS), based on 5% of the Scottish population from the 1991, 2001 and 2011 census responses.
The researchers focused on people aged 16 to 74 who visited the UK for work or study in 2001. After excluding incomplete data, the final analysis included 82,297 people.
Census respondents were asked to select the mode of transportation they use for the longest distance of their typical commute. Active transportation was defined as either walking or cycling. All other commuting modes were defined as “inactive.”
Responses related to nationwide hospitalizations from any cause, cardiovascular disease, cancer, road traffic accidents, deaths from all of these, and prescriptions for mental health problems (sedatives, anti-anxiety medications, and antidepressants) from 2001 to 2018.
A range of potentially influential factors were taken into account, including age, sex, pre-existing health conditions, socio-economic factors and distance to work/school.
Between 2001 and 2018, 4276 participants died (just over 5% of the study population), almost half of whom died of cancer (2023, 2.5%). Approximately 52,804 participants (just over 64%) were hospitalized, of which 9663 (12%) were hospitalized for cardiovascular disease, 5939 (just over 7%) for cancer, and 2668 (just over 3%) for road traffic accidents.
In total, 31,666 (38.5%) study participants were prescribed medication related to cardiovascular disease between 2009 and 2018, and 33,771 (41%) were prescribed medication for poor mental health during the same period.
Compared with sedentary commuters, people who walk to work or school are more likely to be female, younger, work shifts, commute shorter distances, live in urban areas, and are less likely to have dependents and have lower household incomes and educational attainment.
Similarly, bicycle commuters were more likely to be male, younger, shift workers, and urban residents, and less likely to be homeowners or carers.
Taking into account potentially influencing factors, active commuting was found to be associated with a lower risk of death and mental and physical health disorders compared to ‘inactive’ commuting.
Specifically, cycling to work was associated with a 47% lower risk of death, a 10% lower risk of any type of hospitalization, and a 24% lower risk of hospitalization due to cardiovascular disease.
They also found a 30% reduced risk of being prescribed medication for cardiovascular disease, a 51% reduced risk of dying from cancer, a 24% reduced risk of being hospitalised for cancer, and a 20% reduced risk of being prescribed medication for mental health problems.
However, bicycle commuters were twice as likely to be hospitalized after a traffic accident as “non-cycling” commuters.
Walking to work was associated with an 11% lower risk of all-cause hospitalization and a 10% lower risk of cardiovascular hospitalization, as well as a 10% and 7% lower risk of being prescribed medication for cardiovascular disease and mental health problems, respectively.
Because this is an observational study, no firm conclusions can be drawn about causal factors, and the researchers acknowledged that the study has a number of limitations. For example, census responses only reflect a point in time and don’t include general physical activity levels, and prescription data was only available from 2009 onwards.
They point out that census data also does not record combined travel, which could result in overlap between active and “inactive” commuters.
However, they still conclude: “This study strengthens the evidence that active commuting can confer population-level health benefits and contribute to reduced morbidity and mortality. An important finding is that cycling and walking to work are associated with a lower risk of prescribing medication for poor mental health.”
“These findings provide direct evidence of the health benefits of active commuting in a Scottish context, supporting current policy. The study is also more globally relevant for efforts to reduce carbon emissions and move towards more active and sustainable transport modes.”
But the researchers warned that “our findings – that bicycle commuters are twice as likely to be victims of a traffic accident as non-bicycle commuters – reinforce the need for safer cycling infrastructure.”
