In urban environments, the frequency of visits to green spaces, but not views of green spaces from homes, is associated with the use of psychotropic, antihypertensive, and asthma medications. These study findings were published in the journal Occupational & Environmental Medicine.
Previous cross-sectional studies have found that exposure to green spaces has benefits to mental and cardiovascular health. However, longitudinal and experimental studies have found conflicting results.
To clarify the relationship between health and green spaces, researchers from the Finnish Institute for Health and Welfare conducted the Helsinki Capital Region Environmental Health Survey between 2015 and 2016. A random sample of residents (N=16,000) in the 3 largest urban areas in Finland received surveys about use of medications and use of and views of green or blue spaces. Green spaces were defined as forests, parks, fields, meadows, boglands, and rocks and blue spaces were defined as seas, lakes, and rivers.
A total of 5987 individuals completed the surveys. Among study participants:
- mean age was 54 (standard deviation [SD], 16) years,
- 57% were women,
- 66% were married or cohabitating,
- 53% worked full time,
- 24% had a household income ≤€30,000 annually,
- 80% did not smoke, and
- 50% reported consuming 1-6 alcoholic beverages in the past week.
Overall, 20% used psychotropic medication, 27% used hypertensive medication, and 12% asthma medication.
Few individuals indicated they never or rarely used green spaces (17%), 24% had no green space view from their home, 88% had no blue space view from their home, 54% had no available residential blue space, the average road traffic noise was 58 (SD, 14) dB, and NO2 levels from road traffic were 7.3 (SD, 4.3) μg/m3.
The researchers noted that more frequent visits to green spaces was associated with a lower use of antihypertensive and asthma medications.
In the fully adjusted models, for psychotropic medication, the adjusted odds ratios [aORs] were 0.67 (95% CI, 0.55-0.82) for 3-4 times per week and 0.78 (95% CI, 0.63-0.96) for 5 or more times per week.
For antihypertensive medications, the aORs were 0.64 (95% CI, 0.52-0.78) for 3-4 times per week and 0.59 (95% CI, 0.48-0.74) for 5 or more times per week.
Lastly, for asthma medications, the aORs were 0.74 (95% CI, 0.58-0.94) for 3-4 times per week and 0.76 (95% CI, 0.59-0.99) for 5 or more times per week.
The observed associations were accentuated by body mass index (BMI) where individuals who visited green spaces has a slightly lower BMI than those who visited green spaces less often.
After adjusting for covariates, no medication use outcomes were related with the amount of residential green or blue spaces available or views of green or blue spaces from home.
A significant moderation effect was observed for household income, in which the effects of visiting greens spaces were stronger among those with lower income levels compared with higher income levels.
These findings are potentially biased by the fact that healthy individuals are more likely to complete surveys about health.
The researchers concluded that “a higher frequency of green space visits was associated with a lower frequency of psychotropic, antihypertensive and asthma medication use, and the association was not dependent on SES [socioeconomic status].”
Turunen AW, Halonen J, Korpela K, et al. Cross-sectional associations of different types of nature exposure with psychotropic, antihypertensive and asthma medication. Occup Environ Med. Published online January 16, 2023. doi:10.1136/oemed-2022-108491