The secret code to longevity has seemingly been cracked and it’s a lot simpler than you could imagine: planting trees. Yes, plenty of them! According to a new study, planting more trees around you can significantly reduce the likelihood or risk of natural death. 

Friends of Trees, a non-profit organization between 1990 and 2019, went on a tree planting spree on the streets of Portland, Oregon, planting a total of 49,246 trees in that time. Now, a research group has been able to show that each tree planted was associated with a significant reduction in non-accidental and cardiovascular death. This new finding was published in the journal Environment International.

Study Methodology 

As opposed to previous studies “which uses satellite images to estimate the vegetation index, which does not distinguish different types of vegetation and cannot be directly translated into tangible interventions,” this study takes advantage of actual tree planting data from Friends of Trees in Oregon in the preceding 15 years as well as in three age bands: 1-5 years, 6-10 years, 11-15 years after planting.

Data on the number of trees planted in different areas were collected by the team and then cross-referenced with the annual mortality data for those areas obtained from the Oregon Health Authority. 

Researchers considered three causes of death: cardiovascular deaths, chronic lower respiratory deaths, and accidental deaths. In addition to the aforementioned three, non-accidental deaths were also considered which were categorized as all forms of deaths minus accidental deaths. Also, cause-specific mortality data were differentiated by sex and age (<65 years versus > 65).

Results

The results from the study showed that neighborhoods that had more trees planted recorded lower mortality rates (deaths per 100,000 persons). The reduced mortality recorded was more significant for cardiovascular and no-accidental deaths, mostly for men and people above the age of 65. 

The relationship between trees planted and reduced mortality was observed to grow stronger as the trees grew and got older. Reduced mortality associated with older trees planted 11–15 years before was to be 30 percent, literally double the amount observed with younger trees planted in the preceding 1–5 years (15 percent). This data proved that the quote “the older the better” isn’t limited to just friends and wine only but plants too. So, preserving existing and mature trees would be in the best interest of public health.

Although this data doesn’t shed direct light on how trees improve and preserve human health, it does provide good incentives to plant more trees as well as preserve the older ones. For instance, it assists in absorbing air pollution likewise moderating temperatures and curtailing noise — three factors associated with increased mortality.

Above all, it wouldn’t hurt to get more green time as the benefits outweigh the costs. According to estimates from the authors, the annual cost of planting new trees and maintaining urban ones in each of Portland’s 140 census tracts ranges between 3,000-13,000 USD while generating around 14.2 million USD annually in lives saved. 

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