Study uncovers beneficial relationship between gardening and osteoarthritis

Gardening/yardwork is one of the few forms of leisure physical activity that people tend to do more as they age. Osteoarthritis is the most common form of arthritis and a major cause of disability that also tends to occur more as people age. Baylor College of Medicine investigators were interested in studying the relationship between gardening/yardwork and osteoarthritis in an observation study. Their findings were published in Clinical Rheumatology.

“Gardening is an activity people are more likely to participate in as they get older, and age is a strong risk factor for osteoarthritis. Because of this, it is important to understand if gardening is harmful or beneficial for knee health so we can know how to advise people who want to participate in this activity,” said Dr. Grace Lo, associate professor of immunology, allergy and rheumatology at Baylor.

Participants of this retrospective cross-sectional study were part of a large cohort called the Osteoarthritis Initiative (OAI). The cohort primarily started so investigators could look for biomarkers for knee osteoarthritis, and extra efforts were made to evaluate for symptoms and radiographic evidence of the condition in a rigorous and systematic way. Lo and the team were able to add a questionnaire detailing prior participation in leisure physical activity, as it was an unparallelled opportunity to look at the relationship between lifetime physical activity and knee OA. Participants looked back at their lives to answer questions about gardening/yardwork throughout different timeframes: ages 12-18, 19-34, 35-49 and 50-plus.

“Those who gardened were less likely to have X-ray evidence of disease, knee pain or both. That was very reassuring from a knee health perspective,” Lo said.

The study also confirmed the report that as people get older, they are more likely to garden. Additionally, they were able to look at the pattern of participation in gardening over a lifetime. They found that if a person picked up gardening/yardwork from ages 19-34, they were likely to continue it as they aged.

“This is an activity that has longevity to it, and people stick with it once they start. Even better now, we can see that it looks like it’s beneficial from an osteoarthritis perspective,” Lo said.

This report provides preliminary data that gardening/yardwork is certainly not harmful for knee osteoarthritis and suggests that it could be beneficial from an osteoarthritis and knee symptom perspective. While signs of osteoarthritis can appear on X-rays in people’s 40s, many do not become symptomatic until their 60s. The way that osteoarthritis develops and evolves makes it challenging to study. Waiting 20 years to see symptoms develop is difficult to do in a clinical trial.

“Though this study was not designed to identify why gardening/yardwork might show a beneficial relationship with knee osteoarthritis, there have been other studies that prove gardening/yardwork promotes health in other dimensions,” Lo said. “Gardening has been associated with better anxiety and depressive symptoms, better mood and greater socialization. And since there have been clinical trials that have shown anti-depressive medications are helpful in reducing pain in osteoarthritis, this could be a possible way that gardening/yardwork is beneficial. Further studies are needed to test if this is a possibility.”

“This study was the first study to evaluate the relationship between gardening/yardwork and osteoarthritis. It is an observational study, so it will be important if similar findings are seen in other cohorts of patients that have this type of information collected in their participants. This first look is very encouraging, and it looks like gardening is beneficial for knee health,” Lo said.

Dr. Sydney T. Tran, rheumatology fellow at Baylor, and Dr. Jessica C. Lee, recent graduate of Baylor’s rheumatology fellowship program, served as co-authors of this work. Other contributors include Julieann C. Patarini, Jessica C. Lee, Timothy E. McAlindon, Andrea M. Kriska, Bonny Rockette‑Wagner, Charles B. Eaton, Marc C. Hochberg, C. Kent Kwoh, Michael C. Nevitt and Jeffrey B. Driban.
This work was supported by the National Institutes of Health/ National Institute of Arthritis and Musculoskeletal and Skin Diseases funded mentored award K23 AR062127, providing support for design and conduct of the study, analysis and interpretation of the data, and preparation and review of this work.