The Guardian: "It’s unsurprising that social isolation is strongly associated with depression, suicide, anxiety, insomnia, fear and the perception of threat. It’s more surprising to discover the range of physical illnesses it causes or exacerbates. Dementia, high blood pressure, heart disease, strokes, lowered resistance to viruses, even accidents are more common among chronically lonely people. Loneliness has a comparable impact on physical health to smoking 15 cigarettes a day: it appears to raise the risk of early death by 26%. This is partly because it enhances production of the stress hormone cortisol, which suppresses the immune system."
George Monbiot, as usual, does a well-researched piece on human isolation and physical health. Making urban buses and trams fare-free would make a big change. He can't suggest this, of course, because the oil industry would destroy his career. But it is true just the same.