Gardening reduces cancer risk and improves mental health

Gardening is not just a way to get fresh vegetables on your table. A new study proves its effectiveness even against cancer.

Maria Zavialova

As we struggle to keep New Year’s resolutions aimed at improving physical and mental health, a new study from CU Boulder has proven the powerful impact of a common hobby – and that’s gardening.

The first randomized controlled trial of community gardening, commissioned by the American Cancer Society, found that those who started gardening consumed more fiber and had more physical activity – two known ways to reduce the risk of cancer and chronic disease. They also noticed that their stress and anxiety levels dropped significantly.

The findings were published on January 4 in the journal Lancet Planetary Health.

These findings provide concrete evidence that community gardening could play an important role in preventing cancer, chronic diseases and mental health disorders.

Senior author Jill Litt, a professor in the Department of Environmental Studies at CU Boulder

Gardening as a simple way to improve quality of life

Professor Litt was looking for affordable, scalable and sustainable ways to reduce the risk of dangerous diseases, especially among low-income communities.

Gardening seemed like the perfect thing to start with.

No matter where you go, people say there’s just something about gardening that makes them feel better.

Jill Little, who is also a researcher with the Barcelona Institute for Global Health

However, she said, without proven research, it has been difficult to gain support for new programs.

Some small observational studies have indicated that people who garden tend to eat more fruits and vegetables and have a healthier weight. But it was unclear whether healthy people just tend to garden, or whether gardening itself has an impact on health.

Only three studies have applied the gold standard of scientific research, the randomized controlled trial, to the pastime. None have looked specifically at community gardening.


To fill this gap, Jill Little recruited 291 adults who had never gardened before, average age 41, from the Denver area. More than a third were Latino and more than half came from low-income families.

After the last spring frost, 50% of the subjects were assigned to the community gardening group. The rest were assigned to a control group that was asked to wait one year to start gardening.

The gardening group received a free plot in a community garden, some seeds and seedlings, and an introductory course in gardening through the non-profit Denver Urban Gardens program and training partner.

Both groups completed periodic surveys on food intake and mental health, underwent body measurements and wore activity monitors.

Gardening and increased fiber intake

By the autumn, participants in the gardening group ate an average of 1.4 grams more fiber per day than the control group, or about 7% more.

The authors note that fiber has a profound effect on inflammatory and immune responses. This includes how we metabolize food, how healthy our gut microbiome is, and our susceptibility to diabetes and certain cancers.

Although 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.

Co-author James Hebert, director of University of South Carolina’s cancer prevention and control program

Gardening, physical activity and stress management

The gardening group also increased their physical activity levels by about 42 minutes per week. Health institutions recommend at least 150 minutes of physical activity per week, a recommendation that only a quarter of the US population meets. Only 28% of participants met the requirement to visit a community garden two to three times each week.

The study participants also noticed a reduction in stress and anxiety. Interestingly, those participants who had the highest levels of stress and anxiety had the greatest reduction in mental health problems.

The study also confirmed that even novice gardeners can get measurable health benefits from spending time in their first season. And given that they will have more experience and higher yields over time, Litt suspects that such benefits will increase.

The social benefits of gardening

The results of the study are not surprising. It’s (gardening) transformational, even life-saving, for so many people.

Linda Appel Lipsius, executive director of Denver Urban Gardens (DUG)

Denver Urban Gardens (DUG) is a nonprofit organization that helps approximately 18,000 people each year grow their own food in community garden plots.

DUG participants mostly live in areas where access to fresh fruits and vegetables is extremely limited. Some of them are low-income immigrants who currently live in apartments. Having a garden plot allows them to grow food from their native country. Plus, they pass on traditional recipes to their family and neighbors.

The social connection is also huge.

Even if you come to the garden to grow food yourself in a quiet place, you start looking at your neighbor’s plot, share techniques and recipes, and over time the relationship blossoms. It’s not just about fruits and vegetables. It’s also about being in a natural open-air space with others.


Jill Little hopes the findings will encourage health professionals, policymakers and land planners to look to community gardens and other places that encourage people to come together in nature as an important part of public health. The evidence is clear, she said. Recommendations for psychological self-help are collected for you in this article.

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