Gregg Easterbrook writes in The New Republic:

"Recent studies indicate that men and women who practice in any of the mainstream faiths have above-average longevity, fewer strokes, less heart disease, less clinical depression, better immune-system function, lower blood pressure, and fewer anxiety attacks, and they are much less likely to commit suicide than the population at large. These findings come from secular medical schools and schools of public health….

"In the most striking finding, Dr. Harold Koenig of Duke University Medical Center has calculated that, with regard to any mainstream faith, ‘[l]ack of religious involvement has an effect on mortality that is equivalent to 40 years of smoking one pack of cigarettes per day.’…

"Another new study, conducted mainly by researchers at the University of Texas, found that those who regularly attended worship services lived an average of seven years longer than those who never attended."