Smelling Wellness: Associations Between Botanic Garden Scentscapes and Human Health Gains

This pilot study investigated whether ambient biogenic volatile organic compounds (bVOCs)—scent profiles emitted by botanic glasshouse vegetation—could contribute to quantifiable human health and wellbeing outcomes. Over 11 months in 2024 (January–December), human participant trials were conducted at the Oxford Botanic Garden to compare the physiological and psychological effects associated with spending 30 minute exposures in five different vegetation-rich glasshouses, each characterised by a distinct and complex bVOCs profile, with those of a plant-free room. Pre- and post-intervention assessments were conducted on 43 participants, using the State-Trait Anxiety Inventory (STAI), heart-beat rate (beats per minute), and heart rate variability (HRV): the latter two are widely used as an index of regulation of the autonomic nervous system. Significant reductions in STAI anxiety scores and decreases in heart-beat rate were observed, while HRV indices remained stable, relative to the plant-free room, following glasshouse exposure. Distinct scent profiles in the glasshouses included compounds that have previously shown associations with therapeutic effects in clinical settings, indicating the potential of these scented vegetation-rich glasshouse environments to promote the beneficial health effects observed in this study. Overall, these findings highlight the potential public health value of aromatic plant species and the importance of incorporating them into urban green space planning and policy.