Digging in her first allotment, Lucy Jones noticed that her baby daughter liked eating soil. Reading that soil bacteria acts as an organic antidepressant, she decided to investigate the link between nature and mental health. The result, a heartfelt love letter to the outdoors, feels especially urgent in these days of confinement. Jones first experienced the palliative effects of nature in recovery from addiction – when ‘it stroked my hair and held my hand’. The breathless lyricism with which she articulates her wonder at the natural world offers an uneasy contrast with the book’s dense scientific passages. Interviewing experts in neuroscience, psychology and biology, Jones learned that urbanites’ limited exposure to the microbes found in soil weakens immune systems and raises chances of depression. The measurable impact of nature contact is striking. When Philadelphia’s government ‘cleaned and greened’ areas of vacant land, gun violence dropped by 29 per cent. Prison gardening programmes report strong results. In Japan, doctors regularly prescribe ‘forest bathing’. It’s unsurprising that the Oxford Junior Dictionary replaced ‘buttercup’ with ‘broadband’ when threequarters of the UK’S children spend less time outside than its prisoners. Hence the growing popularity of the forest schools movement – improving concentration and ADHD from Somerset to Tower Hamlets. Nature, Jones argues, must become a key factor in health policy and town planning. As the world faces an environmental crisis, we must be ‘galvanised by our ecological grief’ to shift our anthropocentric mindset and develop more holistic healthcare. Moving nimbly from John Clare to Carl Jung, Prince Charles to the Chief Druid, Losing Eden is an earnest, painstakingly researched manifesto for change that seems sadly destined to preach to the converted. Her case may not be new, but the supporting evidence seems irrefutable, presented like this – with care and fervour.