Green health prescribing for older adults: many studies report benefit, few show significant effects, and certainty is low

A UK-led systematic review, with searches to October 2024, assessed green health prescribing and nature-based interventions for adults aged 50 and over in community or residential care Synthesis (Butt et al., PMID 42823701). It included 21 studies, 11 of them randomised trials, covering activities in nature, exercise in green spaces, indoor gardening and horticultural therapy. Findings were synthesised narratively using a GRADE-informed approach and were not pooled.

Many studies reported improvement in at least one outcome, among them quality of life, mental health, physical function, fatigue, loneliness and social connectedness. Statistically significant effects compared with control conditions were uncommon, findings were inconsistent between studies, and overall certainty was low or very low, largely because of small samples, risk of bias and limited replication across outcomes.

The review does not show that green prescribing fails; it shows that the evidence for older adults is weak. Because green space prescribing remains a policy priority, the authors call for pragmatic trials and implementation studies that report health outcomes, cost-effectiveness and healthcare resource use in usual primary and community care. Until then the evidence supports testing it, with outcomes measured, rather than assuming benefit.