Researchers’ study finds obesity risk lessens with gardening

Community gardeners harvest potatoes at the Fairpark Garden. Photo Courtesy Wasatch Community Gardens
Community gardeners harvest potatoes at the Fairpark Garden.
Photo Courtesy Wasatch Community Gardens

If you have never tried gardening, you might want to start. U researchers discovered a correlation between participating in a community garden and having a lower body mass index as well as a decreased chance of obesity. The results were published in the American Journal of Public Health on Thursday.
The study was led by Cathleen Zick, a professor of family and consumer studies at the U. It drew information from the Wasatch Community Gardens, a nonprofit organization that provides the opportunity to grow food in the city along with the Utah Population Database.
Names and addresses of community gardeners were provided by WCG, and that information was matched with records from the Utah Population Database to locate neighbors, siblings and spouses. A total of 198 gardeners were included in the final analysis, along with 67 gardener spouses. The researchers were looking for the health impact of gardening and wanted to account for other factors such as genetics, family diet and neighborhood grocery store access. The gardening individuals were compared with their siblings, spouses and neighbors.
Compared to their neighbors, female community gardeners had a BMI 1.84 points lower on average. For a woman of average height, that equates to more than a 10-pound weight difference. The statistics were even more significant for men, whose BMI was likely to be lower by 2.36 points for those who garden. Gardening women were also 46 percent less likely than their neighbors to be overweight. That statistic was 62 percent for men.
The fact that gardening can provide nutritional benefits is no secret.
“But until now, we did not have data to show a measurable health benefit for those who use the gardens,” Zick said.
The results were not much different when the gardeners were compared to their siblings. The women gardeners had a BMI 1.88 points lower than their sisters. The men’s BMI was 1.33 points lower than their brothers. Genetics and the diet on which the family was raised were determined to have a negligible impact on the results.
While the results are significant, the researchers cannot yet be certain of direct causation. Zick said it is possible the gardeners have lower BMIs because they are more health-oriented individuals. The study did not examine the lifestyle of the gardeners beyond their participation with WCG.
“To the extent that we did observe differences between siblings’ BMI, I think it does point to a causation argument,” Zick said. “Siblings would share the same early family environment where preferences for healthful eating and physical activity behaviors are often established. This makes me a bit more confident that what we are observing may be causal.”
Zick said to prove causation, the study would have to use individuals on the waiting list to use garden as controls.
“Ideally, we would have undertaken a randomized field experiment where we had pre-gardening observations as well as post-gardening observations, but that was not possible,” Zick said.
The researchers predicted the BMIs of gardeners and their spouses would not be statistically different, and they were correct. The study attributes this to the benefits gardening is likely to have on the spouse, including eating the home-grown food and potentially helping out in the garden on occasion.
In 2011, there were more than 18,000 community gardens in the United States and Canada. That number increases each year. Wasatch Community Gardens began operations 24 years ago and includes 11 gardens throughout the Salt Lake Valley.
“Community gardens are experiencing a renaissance in this country,” said Ashley Patterson, executive director of WCG. “They are a relatively inexpensive way to promote healthy eating and community building.”
For those seeking to get some dirt under their fingernails in a community garden, Patterson said it is best to contact WCG and see if there is a garden with an available plot nearby. Some of WCG’s gardens have space available, and others have waiting lists. WCG can also help start a new community garden depending on the availability of land.
“One of the biggest problems in this area is that land in the city is increasingly expensive, which makes it somewhat prohibitive to be used for agriculture,” Patterson said. “That makes it more and more important for us to think outside the box and begin to look at things like roof spaces for our gardens.”