With the passage of time, our body’s repair systems break down; nasty glitches accumulate in our DNA and proteins, metabolism stutters, and cells stop dividing. We are all on a slippery slope to the grave, but research in worms, flies, mice, and monkeys shows that there is nothing inevitable about how fast we slide. Dietary and lifestyle changes – and, perhaps, anti-aging drugs – can slow aging and boost our span of healthy years. A new discovery suggests that a protein in the brain may be a switch for controlling inflammation and, with it, a host of symptoms of aging....