Boys and girls who live and study near green spaces have less oxidative stress

A study led by the Barcelona Institute for Global Health (ISGlobal), a center promoted by the la Caixa Foundation, has analyzed for the first time the relationship between exposure to different green spaces and oxidative stress in boys and girls.

The analysis, published in ScienceDirect, concludes that greater exposure to vegetation is associated with lower levels of oxidative stress and that this association is observed regardless of the physical activity carried out by girls and boys.

Oxygen is essential for a large number of biochemical reactions that keep us alive, but during its oxidation process, harmful reactive substances are generated that the body cannot always quickly neutralize or whose damage it is not able to repair. Then the call occurs oxidative stress, which makes us age or even get sick.

Until now, different studies have indicated that having green spaces in the place of residence has a positive effect on health, especially because they improve mental health and promote physical exercise, which reduces the risk of being overweight or obese.

But less studied what direct effects does this vegetation have on biological processes, for example on inflammation and in oxidative stress. This is especially important to understand the role that green spaces can play in respiratory and allergic diseases.

A study with more than 300 Italian boys and girls

In order to explore if green spaces could be related to lower levels of oxidative stress in the child population, and also if physical activity had a role in this possible association, 323 healthy boys and girls between 8 and 11 years old were analyzed enrolled in five primary schools in Asti, a small town in northwestern Italy.

Parents filled out a questionnaire that included information on how often their sons and daughters engaged in physical exercise. Oxidative stress was quantified in urine by measuring the concentration of the compound isoprostane. On the other hand, green and school spaces were defined using the Normalized Difference Vegetation Index (NDVI), and the portion of vegetation was also estimated. Exposures at multiple sites were obtained by taking into account the NDVI of the home and school, and the time spent by the child at each site.

possible explanations

Several biological mechanisms could explain this direct relationship between green areas and oxidative stress in the child population. First of all, “increased exposure to these areas may contribute to immune development in children and girls by putting them in contact with organisms that usually colonize natural environments”, explains Judith Garcia-Aymerich, researcher and head of the Noncommunicable Diseases and Environment program at ISGlobal, who signs the study as the last author.

In addition, being in contact with green spaces can increase the synthesis of vitamin D through ultraviolet radiation from the sun. This vitamin acts as an antioxidant that prevents the negative effects of oxidative stress and inflammation. Finally, vegetation improves air quality in urban areas.

Physical activity does not influence

Although proximity to green spaces has been associated with increased physical activity, which in turn affects oxidative stress, the study found no evidence that exercise was involved in the association between green spaces and oxidative stress.

Garcia-Aymerich states that “we do not know the short and long-term effects that an excess of oxidative stress has on health, so we must continue to investigate and support public and urban health strategies that favor green spaces.” (I)