Rev Up Immunity

Score one for the pleasure principle: Sex, practiced safely and in moderation, could help keep you from getting sick. Research at Wilkes University in Wilkes-Barre, PA, found that college students who made love once or twice a week had substantially higher levels of immunoglobulin A—or IgA, the body’s first line of defense against colds and flu—compared with those who were either abstinent or had sex three or more times per week.