Chocolate is the ultimate comfort food, a sure-fire stand-by in times of stress, a reliable source of consolation when life has let us down, and a mood-enhancer and romance-inducer in more positive circumstances. But is it at all healthy?If you scoff lots of it, obviously not. But there are a host of medically proven ways in which chocolate — good chocolate, which is to say dark chocolate, with a cocoa percentage of around seventy per cent or more — really is good for us.Research is continuing all the time, and experts have already found that chocolate is good for the heart, circulation and brain, and it has been suggested that it may be beneficial in such major heath challenges as autism, obesity and diabetes.