Although oxygen is essential for a variety of biochemical reactions that keep us alive, its oxidation process generates harmful reactive substances that our bodies cannot always neutralize quickly, often causing irreparable damage, such as that caused by oxidative stress – a phenomenon leading to premature aging or illness.
Many studies have argued that having green spaces in the vicinity of one’s home has a positive effect on health, since greenness improves mental health and encourages physical exercise. However, less attention has been paid to the direct effects of vegetation on biological processes such as oxidative stress and inflammation.
A new study led by the Barcelona Institute for Global Health (ISGlobal) has found that greater exposure to vegetation is associated with lower levels of oxidative stress in children, regardless of the children’s physical activities.
The scientists analyzed a cohort of 323 healthy children aged 8-11 from five primary schools in Asti, a small city in north-western Italy. Parents completed a questionnaire regarding how often their children engaged in physical activity, while oxidative stress was quantified by measuring the concentration of the compound isoprostane in children’s urine. Exposure to residential and school greenness was defined and calculated by using the Normalized Difference Vegetation Index (NDVI).
The researchers found that children with higher exposure to vegetation had significantly lower levels of oxidative stress, regardless of how much (or little) physical activity they were usually engaged in.
Several factors could explain this direct link between green space exposure and oxidative stress. According to study senior author Judith Garcia-Aymerich, the head of the Non-Communicable Diseases and Environment Program at ISGlobal, “increased exposure to these areas may contribute to children’s immune development by bringing them into contact with organisms that tend to colonize natural environments.” Moreover, contact with green spaces can increase exposure to Vitamin D, which is a powerful antioxidant that helps preventing the negative effects of oxidative stress and inflammation. Finally, vegetation improves air quality in urban areas, reducing thus the oxidative stress caused by pollution.
“The short- and long-term health effects of excess oxidative stress are unknown, so we need to conduct further research and support city and public-health strategies that favor greenness,” concluded Dr. Garcia-Aymerich.
The study is published in the journal Environmental Research.