November 15, 2015

New study on effect of trees rooted in Ontario Health Study data

Trees provide us with shade and help to clean the air, but new research shows they may also be helping us out in other ways. Using data from the Ontario Health Study (OHS) and City of Toronto forestry records, researchers at the University of Chicago have shown the positive effect that living near trees can have on our health.

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The study is the first to use data from the OHS, one of the largest health studies of its kind in Canada, and shows the power of this data for researchers studying how to help prevent chronic disease in our communities.

The study found that people who live in neighbourhoods with a higher density of trees on their streets reported having a better perception of their health and significantly fewer cardio-metabolic conditions such as high cholesterol, heart disease, stroke and diabetes. The researchers also discovered that “having 10 more trees in a city block, on average, improves health perception in ways comparable to an increase in annual personal income of $10,000 and moving to a neighbourhood with $10,000 higher median income or being seven years younger.”

This study shows how useful the data that the Ontario Health Study collects is to researchers
– Dr. Philip Awadalla

Researchers used self-reported data involving general health perception, cardio-metabolic conditions and mental illnesses gathered through OHS online questionnaire responses from participants aged 18 and older. “This study shows how useful the data that the Ontario Health Study collects is to researchers,” says Dr. Philip Awadalla, Principal Investigator of the OHS. “This study and others that will follow will help us better understand how the environment affects our health. It is important to understanding the causes of a number of diseases such as cancer, diabetes and Alzheimer’s.”

Participants in the OHS aged 30 to 74 can also choose to provide a blood sample at a Local Study Centre (LSC), which are set up in temporary locations across the province. Planned locations for LSCs over the next several months include Hamilton, Windsor, Ottawa, and Sarnia/Lambton. Within 10 business days of providing a blood sample, participants receive a detailed blood analysis report that they can use to get an overall picture of their health.

The OHS is part a nationwide research platform called the Canadian Partnership for Tomorrow Project (CPTP) that has obtained health data from more than 300,000 Canadians — nearly one in every 50 individuals between the ages of 35-69. Through the OHS, 160,000 Ontarians will participate in the CPTP. The CPTP can also link to other national and international cohorts, which will allow researchers to access data on more individuals and let them study rare cancers and other chronic diseases.

“To get to the bottom of what causes chronic diseases and to develop strategies for prevention and new treatments we have to work together,” says Awadalla. “Initiatives such as the Canadian Partnership for Tomorrow Project are a great example of this. By pooling our resources – in this case data and physical samples – we will better improve the health of future generations.”

To learn more about the Ontario Health Study and to participate visit Information about the Canadian Partnership for Tomorrow Program can be found at