Our parents always told us that we should go play outside. Now, science proves them right. Scientists have found that exposure to green, natural environments may actually lead to a longer lifespan for women.
The study, published Thursday in Environmental Health Perspectives, examined more than 108,630 women living across the United States to see if there was a correlation between exposure to vegetation and mortality. During the eight-year period of research, 8,604 women of that group died.
“We know vegetation is beneficial to mitigate the effects of climate change, and our finding suggest that potential co-benefits prove vegetation to improve health,” said Peter James, the study’s lead author and a research associate at Harvard University.
By using satellite imagery to track seasonal greenery from 2000 to 2008, researchers found that those living in the greenest areas had a 12 percent lower mortality rate than those living in the lowest levels of greenness. They took age, socioeconomic status, race and smoking behaviors into consideration.
Though many researchers have tackled nature’s effects in the past, there have been few studies on its relationship with mortality.
“I don’t think there has been anything with the same geographic scope in the U.S. with the same fine-level exposure information at the individual level,” James said.
The research team found four major mechanisms that push at explaining the reasons behind the relationship between nature and mortality, James said. The increased vegetation provides more opportunities for physical exercise, filters air pollution, offers more space for social interaction and improves mental health.
“We looked at depression as a mediating factor that explained about 30 percent of the relationships between greenness and mortality in our sample,” James said. “E.O. Wilson coined the term ‘biophilia,’ that we’ve evolved with nature to enjoy nature, and so it may be an inherent aspect of us as human beings — our affinity for nature.”
Bonnie Joubert, a scientific program director at the National Institute of Environmental Health Sciences, oversaw the study and said she believes this study supports humans’ natural “affinity for nature.”
“I think it encourages those kinds of healthy activities, that healthy behavior,” Joubert said. “And it reinforces what people already enjoy. I think people naturally enjoy green environments and green spaces.”
Luckily, these greener surroundings are not limited to rural areas. Despite a common belief that rural areas serve as healthier, greener environments, the study proves that greenery doesn’t necessarily favor rural areas.
“We stratified,” James said. “We looked within urban areas and within rural areas, and over 84 percent of our participants live in urban areas. So this is not saying that you need to live in the country to get benefits of vegetation. It actually looks like even within an urban area, those places that have highest levels of greenery have the lowest levels of mortality.”
Though James said they couldn’t announce a cause-and-effect relationship from one study, he acknowledged that researchers are hopeful the evidence will push individuals to begin making changes in their daily lives.
“I think that individuals reading this may think about their own environment and what they could do to increase the greenness,” Joubert said. “They also may think about where they may spend time away from home — if they go out to parks, if they go hiking, if they go running.”
By simply planting this idea in individuals’ minds, James said that he has a good feeling that changes will start to be made.
“I do think the evidence is growing, that there is a positive relationship between vegetation and health,” James said. “I think we allude to this in our paper, that this might be a nice actionable tool for planners and landscapers and architects and policymakers to think about how to improve health within cities.”
As more people get on board with this study’s message, Joubert said she is optimistic about the future.
“It’s not the end,” she said. “I think it definitely should facilitate additional research and hopefully replication of these findings and digging in a little bit deeper in some of the other mediating factors that could be evaluated. It’s nice to see these positive studies.”
