The latest ChangeSurfer column at Betterhumans examines some of the more common studies linking particular lifestyle choices with longevity, and illustrates that these results are not all that useful. You can't choose a particular lifestyle and expect it to improve your healthy lifespan - the real reasons for study results are often buried, rarely obvious, and sometimes counter-intuitive. You have to stick with the known medical conclusions, i.e. not that getting married is good for longevity, but that eating healthily and lowering stress is good for longevity. In other words, ignore the social studies, and look at the medical reasons for longer, healthier lives.