Agricultural or gardening physical activity may slow neurovascular aging and prevent stroke and dementia: an experimental and cross-sectional study

Kiyoshi Kikuchi^1*Seiya Takada²Shotaro Otsuka³Kazuki Nakanishi²Harutoshi Sakakima²Hyuma Makizako²Nobuhiro Tahara⁴Hisaaki Uchikado⁴Naoto Shiomi⁵Satomi Ooba⁴Naoyuki Matsumoto⁶Masato Nishiwaki⁷

• ¹Kurume University, Kurume, Japan
• ²Kagoshima Daigaku, Kagoshima, Japan
• ³Oita Daigaku, Oita, Japan
• ⁴Kurume Daigaku, Kurume, Japan
• ⁵Shiga Ika Daigaku, Otsu, Japan
• ⁶Kumamoto Kenritsu Daigaku, Kumamoto, Japan
• ⁷Osaka Kogyo Daigaku, Osaka, Japan

Background: Agricultural or gardening activity (also known as hobby farming) is a simple strategy that may be effective for maintaining health and preventing lifestyle-related diseases. However, its preventive effect on the development of conditions associated with neurovascular aging (e.g., stroke and dementia) remains unclear. Objective: To comprehensively investigate the preventive role of regular agricultural or gardening physical activity (AGPA) in neurovascular aging and its underlying mechanisms using two approaches. Methods: We conducted an experimental study in which we assessed arterial stiffness, cognitive performance (Flanker and Stroop tests), and circulating biomarkers (e.g., plasmin-α2-plasmin inhibitor complexes, nitric oxide, brain-derived neurotrophic factor) in 12 male students (average age: 22 ± 1 years) before and after three 40-min interventions (resting, cycling, and simulated AGPA) under controlled conditions. We also conducted a cross-sectional study, in which we recruited 161 (79 in the AGPA group and 82 in the control group) hospital-based older individuals (average age: 78 ± 5 years) and assessed their history of stroke, cognitive function, and brain magnetic resonance imaging (MRI) findings. Results: In the experimental study, simulated AGPA reduced arterial stiffness, improved executive cognitive function, and elevated circulating plasmin-α2-plasmin inhibitor complexes, nitric oxide, and brain-derived neurotrophic factor. Brain MRI-assessed cerebral white matter hyperintensities caused by reduced blood flow to brain tissue and stroke prevalence were lower, and cognitive scores (as assessed by the Hasegawa Dementia Scale-Revised) were higher in the AGPA group than in the control group. Conclusion: Our findings suggest that regular AGPA is associated with markers of slower neurovascular aging in older individuals. AGPA induces a combination of general physical activity-related and specific AGPA-related effects; moreover, it may offer similar or even greater benefits than physical activity alone. Therefore, habitual AGPA may serve as an effective preventive strategy for neurovascular aging.