Poor health can put a crimp in your love life. But the reverse is true, too: Good sex may help keep you healthy. "A satisfying sex life can foster good emotional health, which in turn can promote good physical health," says Julia Heiman, Ph.D., director of The Kinsey Institute for Research in Sex, Gender, and Reproduction at Indiana University. Moreover, sex itself may have direct health benefits. For example, orgasm or any loving touch may cause the body to release substances that ease pain, bolster immunity, or elevate mood long after the immediate pleasure passes. Indeed, people who have strong, intimate relationships tend to have fewer chronic diseases and to live longer, some research suggests. So there can be good reasons beyond just pleasure to address any significant loss of sexual appetite or activity, regardless of your age.
(Source: ConsumerReports.org - feb. 2009 "Healthy Sex: His and hers")