The elderly are particularly vulnerable. I'm a Canadian and I'd like to plug an international charitable movement called Cycling Without Age[1]. In helping found a local chapter, I've really started to see how common social isolation is, independent of health and wealth and even in urban density. But I've also seen how even a single short social connection can have enduring benefit. Unlike some afflictions of aging, loneliness is a relatively solvable problem.
Take care of your older friends and family and neighbours, and maybe even offer to connect with a stranger once in a while. It's good for everyone! :-)