Anyone who has ever gardened knows what a labor of love it can be as you dig deep in the dirt to plant seeds and then take pride in your first crop, but new research shows it also translates into better health.
It turns out that community gardens in urban areas can have folks eating more fresh food and getting exercise, while it can also ease stress and anxiety.
“These kind of interventions that have a strong social organization, that have access to nature and contact with nature, where there's active participation, these are the ingredients that we need to think about to have successful interventions to address a whole variety of health outcomes,” said senior study author Jill Litt. She is a professor in the department of environmental studies at University of Colorado, Boulder, and a senior scientist at the Barcelona Institute for Global Health.
For this study, researchers wanted to do a randomized, controlled trial on community gardens, to add to information from previous gardening studies.
Litt said she was approached by Denver Urban Gardens to study the benefits when there were only 40 gardens in the city. Now, there are 180.
“It hooked me. It was the most fascinating system where we could actually see how behavior change happens,” Litt said. “People were connecting to the landscape. They had social relationships, they were building trust, they had sense of purpose and belonging.”
While earlier studies were observational, to study the impact of community gardening with a randomized controlled trial, Litt recruited 291 adults who were not already gardeners. More than one-third of the participants were Hispanic. More than half lived in low-income households.
About half of these adults were asked to wait for one year to start participating in a community garden (the "control" group), while the other half were assigned a free plot and given seeds, seedlings and an introductory gardening course through the Denver Urban Gardens program. All were also given activity monitors.
Each of the study participants were assessed at baseline with surveys about nutritional intake, and mental health and body measurements.
In the end, the researchers found that those who were gardening ate an average of 1.4 grams more fiber each day — a 7% increase — than the control group.
Doctors recommend getting about 25 to 38 grams of fiber daily, though most people consume far less. Fiber affects inflammatory and immune responses that influence metabolism, the gut microbiome and susceptibility to chronic disease, including diabetes and cancer, according to researchers.
“It's anti-inflammatory to have a high-fiber diet based in fruits and vegetables. That's really important for disease progression, getting in before disease takes hold,” Litt said.
The gardeners also increased their physical activity by about 42 minutes each week, the investigators found.
“Inactivity is a risk factor for chronic disease, cancer specifically, and other chronic diseases, so we want to try to get people to be more active,” Litt said.
The study gardeners were also less anxious and stressed, and they improved their social connections.
“What we saw were people building bridges and relationships with others, and they were based on something that they all had in common, which then also reinforces their interest and ability to stay involved in that activity,” Litt said.
This research has shown these community gardens do have health benefits, she added.
The community garden context of this study is important, Litt said, drawing on past research. While home gardening is also valuable, community gardening had more impact, her research has shown.
“That's the other piece that I think's unique about this, is we're able to test a nature-based solution that's nearby in people's communities,” Litt said. “What we're really aiming for is affordable, scalable, sustainable interventions that people can access from very close to where they live, maybe where they work, maybe where they go to school. This provides a good urban example of something that is accessible and available.”
To be successful, the gardens need to have community buy-in. They need to be public-private partnerships, to be part of a structure and to be able to draw on a base of volunteers, Litt said.
The study, which was partially funded by the American Cancer Society, was published Jan. 4 in The Lancet Planetary Health.
Colleen Spees, an associate professor at Ohio State University, has also studied the impact of gardening on health. Spees' studies are urban community garden-based and typically involve vulnerable populations, including those who are overweight and obese, and cancer survivors.
Spees sees value in gardening both for its access to healthy food and for the experience of being out in nature.
“When we remove ourselves from what I call the chaos of our normal lives, there seems to be some sort of quieting effect,” Spees said. "When you take those moments that quiet yourself, free from social media, free from the telephone, cellphones, free from all of that, the noise of the world, most people find that can reduce anxiety and reduce stress.”
Litt's trial “adds benefit to the growing body of knowledge that gardening and/or consuming primarily more towards a plant-focused dietary pattern absolutely can contribute to positive mental and physical health impacts,” Spees said.
While many people would enjoy gardening or harvesting from a garden, it's important to include a skilled nutrition component to educate people about how to cook the food, Spees suggested.
Spees said she is happy to see that policymakers on a national level are now seeing the benefits of produce, farmer's markets and community gardens.
“This is a paradigm shift for our country," she said. "We've been waiting for it a long time and we are in the midst of it. I hope to see it come to fruition."
The U.S. National Cancer Institute has more on physical activity and cancer.
SOURCES: Jill Litt, PhD, professor, department of environmental studies, University of Colorado at Boulder, and senior scientist, Barcelona Institute for Global Health; Colleen Spees, PhD, MEd, RDN, associate professor, division of medical dietetics, Ohio State University College of Medicine, Columbus; The Lancet Planetary Health, Jan. 4, 2023