Gardening May Help Reduce Cancer Risk and Improve Mental Health

A new study suggests that gardening offers health benefits that may reduce risks of chronic diseases such as cancer and improve mental health.

The study followed 145 people who had never gardened through planting and harvest, assessing physical and mental health. Gardeners ate more fiber, exercised more, increased social contact and experienced less anxiety .

Health Effects of Community Gardens

University of Colorado Boulder researchers suggest that gardening, including gardening as a hobby, may reduce the risk of serious conditions such as cancer and mental health disorders.

Gardeners ate more fresh produce and fiber, exercised through garden maintenance and interacted more socially. These factors are protective against cancer, mental health disorders and other chronic conditions.

Earlier studies suggested some benefits, but the CU Boulder study is the first randomized controlled trial specifically examining community gardens, where people garden alongside one another.

Benefits of Community Gardening Demonstrated for the First Time

The study enrolled 291 new gardeners, with a mean age of 41.5. Men accounted for 18% (52 participants), and half had low incomes.

Work in Denver and Aurora gardens began in May and covered 3 planting-harvest periods over 1 year. Half gardened during the 3 periods, while controls did not.

Participants received introductory training at Denver Urban Garden, seeds, seedlings and a 10-square-meter plot. Controls received the equivalent in payment.

Coauthor Prof. Jill S. Litt said participants spent an average 90 minutes gardening, visiting at least twice weekly.

"Since we included only new gardeners, we found that being new was no barrier to success."

Gardening Encourages Healthy Behaviors

Before allocation, participants underwent health screening and completed stress, anxiety and diet questionnaires. Hip-worn accelerometers measured activity for 7 days.

Gardeners ultimately ate slightly more fiber than controls, but remained below the recommended 25–38 grams daily. During harvest, they also exercised approximately 5 minutes more than controls.

Rebecca Crane-Okada, Ph.D., R.N., an advanced oncology nurse and professor at St. John's Cancer Institute in Santa Barbara, California, who was not involved, said: "I think it is a great study when you look at the logistics. It must have been very complicated to carry out."

Litt said the work addressed a gap: smaller observational studies linking gardening with health could not determine whether gardening produced healthier lifestyles or healthier people chose to garden.

She said the study demonstrated that "a holistic intervention such as hobby gardening can influence several outcomes—fiber intake, moderate physical activity, psychosocial health, stress and anxiety—in an acceptable, affordable way across social, economic and demographic backgrounds" .

Gardening Improves Physical and Mental Health

Litt noted that gardening addresses several factors important for reducing chronic disease risk and improving health. Crane-Okada said community gardens offer opportunities to address known "modifiable risk factors" for conditions such as:

• Cancer
• High blood pressure
• Type-2 diabetes

Associate Professor Denise Dillon, a psychologist at James Cook University in Singapore, was not involved but has previously published on gardening's mental health benefits.

"Our participants who gardened socially scored higher in subjective well-being and resilience than solitary home gardeners or nongardeners, despite reporting similar stress. Extensive evidence from many research approaches shows the restorative benefits of direct exposure to nature, whether physiological or psychological."

Dillon also added that "abundant evidence from numerous research approaches demonstrates the physiological or psychological restorative benefits of direct contact with natural environments" .

Benefits of Gardening with a Social Group

Crane-Okada said community gardens offer outdoor contact with nature and a connection to the earth. Preparing a garden benefits nutrition and physical activity, while belonging to a community supports mental health.

People diagnosed with chronic conditions such as cancer may also benefit psychologically from time in a community garden.

"Gardening generally involves outdoor physical activity and focusing on something beyond yourself, so it can also be mindful. Doing it within a community, as in this study, can provide additional social support."