People who participate in community gardening are more likely to be in a healthy weight range than people from comparable backgrounds who are not involved with community gardens, a study in the US has found.
It’s worth noting though that the design of the study means it is capable only of showing an association between community gardening and having a healthy weight. It does not prove cause and effect, and one possibility is that the findings simply reflect that people who engage with community gardening are more likely to have a healthy lifestyle anyway.
However, the results do add to a body of evidence which support the health benefits of community gardens, and the US researchers suggest that randomised controlled trials should now evaluate the impact of community gardening upon participants’ weight.
In the latest edition of JournalWatch, Dr Melissa Stoneham, of the Public Health Advocacy Institute WA (PHAIWA), endorses the US researchers’ recommendation that new urban developments should “design in” community gardens. She also would like to see established suburbs redesigned to integrate health-promoting features like community gardens.
Community gardens: producing health
Dr Melissa Stoneham writes:
In recent times I have had a bit to do with community gardens, with most being funded under the Commonwealth’s Healthy Community Initiative with local governments, which aims to increase physical activity and healthy eating in certain adult populations.
In June 2013, the garden was awarded a nationally funded award sponsored by the Australian Open Garden Day organisation.
The Greenough garden uses organic synergistic and aquaponic methods to produce over 35 varieties of vegetables, herbs and fruit.
Clearly this garden provides locally grown and competitively priced produce to the local community, but a recent study in the US suggests that community gardening can help people achieve a healthy weight.
The study, conducted by Caethleen Zick and colleagues based at the University of Utah, examined the relationship between participation in community gardening and weight.
It found that people who participate in community gardening have a significantly lower body mass index—as well as lower odds of being overweight or obese—than do their non-gardening neighbours.
The article, Harvesting More Than Vegetables: The Potential Weight Control Benefits of Community Gardening, was published in the American Journal of Public Health. It acknowledges that previous research in community garden settings has provided a variety of social and nutritional benefits to neighbourhoods but states there was little evidence to demonstrate that working in a garden could show a measurable health benefit.
Researchers gathered 198 community gardeners both men and women, from Salt Lake City, Utah and measured their body-mass index, based on their height and weight. According to recent Centers for Disease Control and Prevention data, Utah is the 45th most obese state in the United States with 57 per cent of adults overweight (BMI >25) and 22.5 per cent of adults obese.
Research methods included comparing community gardeners’ BMIs, and odds of being overweight or obese, with three control groups, all based in Salt Lake City.
One control group was a mix of unrelated people from the same geographic neighbourhood as the garden. This group shared similar physical environments, such as walkability and proximity to food shops and stores, as well as economic status.
The second control group was same sex siblings, where it was expected they shared genetic predispositions for weight and family influences on diet and physical activity. The third group was married spouses of the gardeners, as it was assumed they would be likely to share lifestyle and food choices, including food grown in the community garden.
Gardeners recruited for the study included 423 adults who had participated at one of the community plots facilitated by a not-for profit community gardening scheme for at least one year between 1995 and 2010.
Data for control groups were drawn from administrative records, using the Utah Population Database, a multi-faceted data resource used by health researchers. It includes a large set of Utah family histories, and links to publicly-available historical birth, marriage, and driver’s license records.
A total of 375 gardeners were linked to BMI information in the database. Once linked, driver’s license records were used to build a sample of neighbours—individuals matched for age, gender and residential location, and Utah marriage, divorce and birth records to identify siblings and spouses.
Eventually, data on 198 gardeners and 67 spouses were included in the analyses, and height and weight information came from driver’s license records following the commencement of their community gardening.
Results showed that women community gardeners had an average BMI 1.84 lower than their neighbours, which translated to a 4.9 kilogram weight difference for a woman 165 cm tall. For men, the BMI was lower by 2.36 for gardeners, which is a difference of 7.25 kilograms for a man who is 178 cm tall when compared to the neighbourhood cohort.
Gardeners were also less likely to be overweight or obese, showing 46 per cent less for women gardeners, and 62 per cent less for men gardeners.
When the researchers looked at the BMIs of individuals related to the gardeners, including siblings and spouses, comparative data was found. Same sex siblings revealed a similar advantage to unrelated neighbours and women in the community gardening group had a BMI 1.88 lower than their sisters. For men, the difference was 1.33 lower for the gardeners compared to their brothers. Both differences were statistically significant.
For spouses of married gardeners, there was no difference in BMI or odds of being overweight or obese. That finding was not surprising, as researchers had expected that spouses would benefit from eating food produced in the garden, and perhaps from assisting with gardening activities.
The last few sentences of the article, and a focus I find particularly important, is the recommendation that new urban developments’ “design in” facilitates such as community gardens, and the more established suburbs be redesigned so they integrate features that promote healthy lifestyles.
It is a well-known fact that community gardens provide many benefits to active participants such as providing opportunities to relax, undertake physical activity, socialise and mix with neighbours, share across culturally different backgrounds and religions, learn about horticulture and sustainable environmental practices and be a source of low-cost fresh produce for a healthy diet.
When you add in the findings of this research, which has demonstrated a considerable difference in BMI of gardeners compared with other community groups, community garden integration in our local suburbs seems to be what one of my younger colleagues described as: “a no brainer”.
• Harvesting More Than Vegetables: The Potential Weight Control Benefits of Community Gardening. Cathleen D. Zick, PhD, Ken R. Smith, PhD, Lori Kowaleski-Jones, PhD, Claire Uno, MLIS, and Brittany J. Merrill, BS. June 2013, Vol 103, No. 6; pp 1110-1115.
The Public Health Advocacy Institute WA (PHAIWA) JournalWatch service reviews 10 key public health journals on a monthly basis, providing a précis of articles that highlight key public health and advocacy related findings, with an emphasis on findings that can be readily translated into policy or practice.
The Journals reviewed include:
- Australian & New Zealand Journal of Public Health (ANZJPH)
- Journal of Public Health Policy (JPHP)
- Health Promotion Journal of Australia (HPJA)
- Medical Journal of Australia (MJA)
- The Lancet
- Journal for Water Sanitation and Hygiene Development
- Tobacco Control (TC)
- American Journal of Public Health (AMJPH)
- Health Promotion International (HPI)
- American Journal of Preventive Medicine (AJPM).
These reviews are then emailed to all JournalWatch subscribers and are placed on the PHAIWA website. To subscribe to Journal Watch go to http://www.phaiwa.org.au/index.php/other-projects-mainmenu-146/journalwatch
PHAIWA is an independent public health voice based within Curtin University, with a range of funding partners. The Institute aims to raise the public profile and understanding of public health, develop local networks and create a statewide umbrella organisation capable of influencing public health policy and political agendas. Visit our website at www.phaiwa.org.au
Previously at Journal Watch: