Do you know gardening can have a powerful impact on your mind and body? Funded by the American Cancer Society, the first-ever, randomized, controlled trial of community gardening found that those who started gardening ate more fiber and got more physical activity--two known ways to reduce the risk of cancer and chronic diseases. They also saw their levels of stress and anxiety significantly decrease.
Findings published in the journal Lancet Planetary Health, read "community gardening could play an important role in preventing cancer, chronic diseases, and mental health disorders." Some small observational studies have found that people who garden tend to eat more fruits and vegetables and have a healthier weight.
But it has been unclear whether healthier people just tend to garden or whether gardening influences health. To fill the gap, senior author Jill Litt, a professor in the Department of Environmental Studies at CU Boulder, recruited 291 non-gardening adults, an average age of 41, from the Denver area. More than a third were Hispanic and more than half came from low-income households. After the last spring frost, half were assigned to the community gardening group and half to a control group that was asked to wait one year to start gardening.
The gardening group received a free community garden plot, some seeds and seedlings, and an introductory gardening course through the nonprofit Denver Urban Gardens program and a study partner. Both groups took periodic surveys about their nutritional intake and mental health, underwent body measurements, and wore activity monitors.
By fall, those in the gardening group were eating, on average, 1.4 grams more fibre per day than the control group--an increase of about 7 per cent. The authors note that fiber exerts a profound effect on inflammatory and immune responses, influencing everything from how we metabolize food to how healthy our gut microbiome is to how susceptible we are to diabetes and certain cancers. While doctors recommend about 25 to 38 grams of fiber per day, the average adult consumes less than 16 grams. "An increase of one gram of fiber can have large, positive effects on health," said co-author James Hebert, director of the University of South Carolina's cancer prevention and control program.
The gardening group also increased their physical activity levels by about 42 minutes per week. Public health agencies recommend at least 150 minutes of physical activity per week, a recommendation only a quarter of the U.S. population meets. With just two to three visits to the community garden weekly, participants met 28 per cent of that requirement.
Study participants also saw their stress and anxiety levels decrease, with those who came into the study most stressed and anxious seeing the greatest reduction in mental health issues. The study also confirmed that even novice gardeners can reap measurable health benefits.