The therapeutic benefits of gardening on cognition have been suggested in several studies across a range of populations including the elderly and those displaying cognitive impairments. Given that gardening appears to improve cognitive performance and memory, Park and colleagues (2019) conducted a study to determine the effects of gardening physical activity on the levels of brain nerve growth factors present in the serum of senior individuals. Brain-derived neurotrophic-factor (BDNF) and vascular endothelial growth-factor (VEGF) are thought to be associated with cognition and memory. Platelet-derived growth-factor (PDGF) is known to promote blood vessel growth and support neuronal survival. The present study employed a before and after non-experimental design where the participant population received an experimental gardening treatment, and the serum concentrations of BDNF, VEGF, and PDGF before and after the gardening treatment were quantified. A population of 41 subjects (68% women) with an average age 76.6 years participated in the study. The low to moderate-intensity physical activity gardening treatment consisted of a single 20-minute intervention that included pulling weeds, digging, fertilizing, raking, transplanting, and watering. Serum concentrations of BDNF and PDGF were increased by 8.4% and 13.5% (p < 0.05 and <0.01) respectively following the short gardening treatment, while the serum concentrations of VEGF were not statistically different from the concentrations present before the treatment. The before-and-after experimental design used in the present study is a reasonable approach although it is vulnerable to risks to internal validity. However, it can provide preliminary evidence for intervention effectiveness. Therefore the importance of the present preliminary study is to suggest a possible mechanism for the cognitive and memory benefits of gardening as a low to moderate physical activity and justifies further randomized controlled trials to more robustly explore the therapeutic role of gardening in cognitive functions and memory.
Park, S-A, Lee, A-Y, Park, H-G and Lee, W-L (2019). Benefits of gardening activities for cognitive function according to measurement of brain nerve growth factor levels. International Journal of Environmental Research and Public Health. 16(5):760. https://doi.org/10.3390/ijerph16050760