Air and noise pollution, traffic jams, rushing, and even high temperatures make many cities a hostile environment that harms physical and mental health. To mitigate its negative impact it is important to get away to natural spaces whenever possible, but now a new study has found that exposure to urban green spaces also has great advantages because people who live near them for a long time enjoy better health and their biological aging is slower.
The research has been published in the scientific journal Science Advances and reveals that the biological age of people who live near areas with vegetation is 2.5 years younger, on average, than that of those who do not have green areas close to home. “Our study shows that proximity to green spaces caused biological or molecular changes that can be detected in our blood,” said Lifang Hou, professor of preventive medicine at Northwestern University Feinberg School of Medicine and principal investigator of the study.
A person’s biological age can speed up or slow down depending on their lifestyle, and when they are older than their chronological age, they increase their risk of developing age-related health problems, such as cancer, cardiovascular disease or Alzheimer’s, says the expert, who adds that biological age “really depends on what we do on a daily basis,” including what we eat and our physical activity.
“The environment we live in, specifically our community and access to green space, is important to keeping us healthy as we age”
The study, however, highlights that this does not depend solely on what each individual does for their own health, but that the characteristics of their place of residence and its surroundings are also important. “When we think about staying healthy as we age, we typically focus on things like eating right, exercising and getting enough sleep,” says Kyeezu Kim, first author of the study and a postdoctoral fellow in preventive medicine at the Feinberg School of Medicine at Northwestern University. “However, our research shows that the environment we live in, specifically our community and access to green spaces, is also important in keeping us healthy as we age.”
How does the natural environment affect our body?
The researchers examined long-term exposure to surrounding green spaces and how they influence biological aging in 924 people residing in four US cities. They compared age-related biological changes in study participants over a 20-year period (between 1985 and 2006) with data on green spaces near their homes.
Hou explained that they used DNA from blood to measure biological age at the molecular level by analyzing small changes in the functioning of genes related to the aging process. They used satellite imagery and a widely accepted vegetation quantification measure to assess green spaces, Kim said, adding that they had also identified important parks near participants’ homes.
This information helped identify the location and amount of vegetation, although it did not provide details about the type of plant life, such as whether it was a golf course or a forest trail, or about the quality of the green spaces. Another unanswered question was why the rate of biological aging does not appear to be the same across races, genders, and socioeconomic levels, as the researchers found that black individuals with the most access to green spaces were only one year old. less in biological age compared to the study average of 2.5 years.
For this reason, experts have pointed out that it is necessary to continue research to determine how people could benefit from the vegetation and what other social factors could be involved. However, in Hou’s opinion, his findings should encourage people to think more about their environment when making healthy lifestyle choices, and take it into account alongside diet, sleep and exercise.
Usama Bilal, urban epidemiologist, Assistant Professor of Epidemiology in the Department of Epidemiology and Biostatistics and in the Urban Health Collaborative of the School of Public Health at Drexel University in Philadelphia (USA) has highlighted the relevance of the study in statements to SMC Spain: “The work is very consistent with the existing evidence that highlights the importance of the existence of green spaces for our health.”
And he points out: “I don’t see why the results could not be extrapolated to Spain. The important thing is that these studies on greenness are usually quite sensitive to the climate of each zone (because the basal greenness varies a lot based on the climate of each zone, of course: Asturias is different from Almería). In this case, they use four very different cities: Oakland in California as a more temperate area with a climate similar to the Mediterranean, Chicago and Minneapolis as areas with cold winters, and Birmingham, Alabama as a much hotter and more humid subtropical area.
“This study has been carried out in the US, with a society that uses the parks less than the Spanish society. In this sense, and now that the heat is coming, the use of parks as resources that promote and protect the health of citizens is essential”, concludes Manuel Franco, epidemiologist, professor and researcher at the Universities of Alcalá and Johns Hopkins. Spokesperson for the Spanish Society of Public Health and Health Administration SESPAS, also speaking to SMC Spain.
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