Health: An unhealthy obsession

Great strides in science and medicine have improved our capacity to treat and cure serious illnesses. Our standard of living has improved as has our ability to live a long and active life.

Yet we worry incessantly about the food we eat, the air we breathe, the amount of exercise we take and the number of vitamins we ingest. We scrutinise our bodies and minds for signs of malaise. Why are we so troubled by our health - and what can be done to make it better?