A prospective trial of greening a city to improve heart health

December 17, 2019

Here is some good news. 

Consult the website ClinicalTrials.org and you will find a fascinating trial described under the designation NCT03670524.

The study is also known as Health, Environment and Action in Louisville or by its acronym HEAL Louisville is also referred to as Green Heart Louisville.  The study is sponsored by the University of Louisville, National Institute of Environmental Health Sciences (NIEHS), and The Nature Conservancy.  The official description of the study goes like this;

“The purpose of this study is to examine how the environment and neighborhood characteristics affects the health of the area residents. The study will help determine how changing neighborhood characteristics, such as green space, affect heart health, risk factors for other diseases, sense of well- being or neighborhood cohesion.”

It is an interventional clinical trial with a proposed 700 participants (n=700) from 30 to 70 years of age.  You’ve got to live in Louisville.  This will be a non-randomized parallel assignment, open label interventional trial with longitudinal follow up that will assess cardiovascular and metabolic effect of an incredibly unique intervention.  The Nature Conservancy is going to plant trees in Louisville and then the University is going to track what happens.

ClinicalTrials  describes the study: “Using greenness as a therapeutic intervention, we will plant shrubs, grasses, young and mature trees (40-50 ft in height), so that we can evaluate changes in health and pollution, 2 years after planting.”

There won’t be a control group.  You cannot plant placebo trees. They will however compare effects in neighborhoods that did receive trees with those that didn’t.

The Nature Conservancy is a cosponsor of this study.  Together with volunteers in Louisville they hope to raise $8 million dollars to plant 8,000 trees.

Listen to the full story:  https://www.nature.org/en-us/about-us/where-we-work/united-states/kentucky/stories-in-kentucky/green-heart-project/

See a short feature from PBS: https://www.youtube.com/watch?v=e0QLQe13gww

This is the first controlled experiment to test whether the greening of an urban area will change health.  While we have a growing body of research strongly suggesting an association between green surroundings and health outcomes, as we all know association doesn’t prove causation.

This may be the most upbeat news I have heard in a long time.

Read more here: https://greenheartlouisville.com

The University researchers are tracking a long list of markers before and after this two year trial related to heart disease including blood pressure, pulse wave analysis, weight, lean mass, body fat, height, waist, hip measurements, central adiposity, FEV1 and FVC percentages, oral microbiome, genetic phenotyping, urine metabolites of organic compounds, biogenic VOCs and nicotine metabolites , catecholamines, lipids (LDL-mg/dl, HDL-mg/dl, total cholesterol-mg/dl),  heavy metals in toe nails, cortisol in hair psychologic assessments of perceived stress, depression, Well-being, occupational exposures to toxins, health perception, neighborhood cohesion, tobacco and alcohol use, physical activity, education, income, medical history, platelet count, CBC, liver function, c-reactive protein, and no doubt some other characteristics or measurements that I neglected to mention.