The Journal Lancet Planetary Health published a study funded the first-ever, randomized controlled trial of community gardening by the American Cancer Society. Researchers found that those who started gardening ate more fiber and got more physical activity—two known ways to reduce risk of cancer and chronic diseases. They also saw their levels of stress and anxiety significantly decrease.

Those in the gardening group were eating, on average, 1.4 grams more fiber per day than the control group—an increase of about 7%.

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 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% 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 of the pastime in their first season. As they have more experience and enjoy greater yields, Litt suspects such benefits will increase.

Read more about the study here.