Outdoor gardening activity with different frequency and duration may be associated with reduction of total and cause-specific mortality risk for general U.S adults: Findings from the NHANES

Background and Aims Engaging in recommended levels of physical activity (PA) is associated with a reduced overall mortality rate and cause-specific mortality rates. Our study aims to examine the relationship between gardening-specific PA and all-cause and cause-specific mortality based on representative U.S. adults. Methods and Results A total of 13,812 adults representing 663.5 million non-institutionalized U.S. adults were included from the National Health and Nutrition Examination Survey. Self-reported gardening activity (GA) were assessed by a validated questionnaire, and outcomes of interest were all-cause mortality and mortality specific to certain causes. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using survey-multivariable Cox proportional hazards models. During a median follow-up period of 16.8 years (Interquartile range =14.8-18.7), there were 3,476 deaths. After adjusting for potential covariates, we found that participants exposed to GA were more likely to have a lower risk of total mortality [HR (95% CI): 0.76 (0.68, 0.85), P-value < 0.001], cancer-specific mortality [HR (95% CI): 0.81 (0.67, 0.99), P-value < 0.05], cardiovascular disease mortality [HR (95% CI): 0.65 (0.53, 0.80), P-value < 0.05], and respiratory disease mortality [HR (95% CI): 0.66 (0.45, 0.98) , P-value < 0.05], compared to those without GA exposure. Furthermore, engaging in GA more frequently and for longer durations was significantly associated with a lower total mortality risk. Conclusion Our study provides evidence that engaging in GA is associated with a decreased risk of overall and cause-specific mortality. However, further longitudinal or interventional studies are needed to investigate the potential benefits of GA.