According to a new study published in Environmental Health Perspectives, American women who live in homes surrounded by more vegetation have significantly lower mortality rates than women who live in areas with less greenery.
Researchers with the Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital used data from 108,630 women enrolled in the Nurses' Health Study across the United States from 2000 to 2008, comparing the women's risk of mortality with the level of vegetation surrounding their homes (based on satellite imagery from different seasons and various years).
They found that women who lived in the greenest surroundings had a 12 percent lower overall mortality rate versus those living in the least green areas. The associations were strongest when it came to deaths related to cancer and respiratory diseases: Women living in areas with the most vegetation had a 34 percent lower rate of respiratory-related deaths and a 13 percent lower rate of cancer deaths compared with those who had the least vegetation around their homes.
So what's the association between greenery and mortality? Of course women living in green, natural environments aren't experiencing the full negative health effects of air pollution, noise, and extreme heat, but researchers also theorize that areas with more vegetation also offer increased opportunities for physical activity and social interaction, and therefore lower stress levels. In fact, improved mental health, measured through lower levels of depression, was estimated to explain nearly 30 percent of the benefit from living around more trees, the authors of the study said.
"We were surprised to observe such strong associations between increased exposure to greenness and lower mortality rates," said Peter James, research associate in the Harvard Chan School Department of Epidemiology. "We were even more surprised to find evidence that a large proportion of the benefit from high levels of vegetation seems to be connected with improved mental health."