The road to good health is a green one thickly lined with trees.

A recent study found that people who live in bucolic neighborhoods filled with greenery might have a lower risk of heart disease and stroke. Research findings indicate it may come down to a lighter burden of stress.

University of Louisville researchers recruited 408 people of different ages. Over a five-year period, they tested the blood and urine of these volunteers for biomarkers of blood vessel injury and cardiovascular disease. The scientists then matched the participants’ home addresses with a federal map that uses satellite imagery collected by both NASA and the U.S. Geological Survey that shows vegetation density.

The researchers found those living in the greener neighborhoods had lower levels of the stress marker epinephrine in their urine. They also found lower levels of a second marker in the urine indicating fewer cell-damaging free radicals, pointing to better health.

The results further suggested participants in the greener areas had a greater ability to repair blood vessels.

These findings appeared to be independent of demographic factors such as age and ethnicity, in addition to health factors such as smoking or the use of statins. Statins lower cholesterol and can help stave off heart disease.

Previous studies have shown an association between good health and green spaces. But researchers pointed out that this previous work relied on self-reported questionnaires and used less-rigorous data.

Researchers said making a neighborhood greener is a potentially significant public health intervention. So, help improve your own and your neighbor’s health. Plant a tree.