The beneficial effects of spending time in nature has been found to reduce anxiety and boost the immune systems of children. Recent research finds that any contact with plant life reduces inflammation and improves the immune systems of older adults, whether it’s gardening, tending indoor houseplants, or visiting parks.
Aging cells are prone to an exhaustion of their T-cells, important immune fighting cells which lose potency over time during natural aging processes. When older adults aged 61-77 years old took part in a six-month regime of what is dubbed “horticultural therapy”, blood samples revealed that the contact with plant life had reduced markers of T-cell exhaustion while also lowering markers of inflammation.
As a normal part of aging, cells undergo a process called immunosenescence which is a deterioration of the immune system. These aged cells can no longer divide. When T-cells are exhausted, it impairs the body’s immune system to deal with infections, cancers, and other diseases.
Study participants showed a reduced inflammatory marker of IL-6 (interleukin 6) during the horticultural therapy program which provided the older adults with hour-long sessions. Interleukin 6 increases with age and is closely linked with causes of mortality in the aging population. A reduction in this inflammatory marker was seen with sessions that included both indoor and outdoor activities centered around physical contact with plants. The participants started with weekly sessions, then progressed into monthly sessions.
Horticultural therapy is already practiced in some hospitals to improve quality of life in terminally ill patients; but having solid evidence that it is reducing inflammation and improving the function of T-cells will ensure the adoption of this practice across many healthcare disciplines.
Whatever you can do to keep these immune cells from becoming overburdened will make a difference in how smoothly you experience the process of aging. Research is currently being conducted to find more supplements and medications which fight the body’s immunosenescent process. These “anti-senolytic” compounds generally have a basis in nature, such as the flavonoids and polyphenols found in fruits and vegetables.
Glenn Choon Lim Wong, PhD, Ted Kheng Siang Ng, PhD, Jia Le Lee, PhD, et al. Horticultural Therapy Reduces Biomarkers of Immunosenescence and Inflammaging in Community-Dwelling Older Adults: A Feasibility Pilot Randomized Controlled Trial, The Journals of Gerontology: Series A, glaa271, https://doi.org/10.1093/gerona/glaa271