Sex ends at 70 for most people, study finds

The average person's sex life ends by the age of 70, according to a report published Tuesday in the British Medical Journal.

Men age 30 have an average of 35 years of sexually active life remaining, compared with 31 years for women, researchers at the University of Chicago's department of obstetrics and gynecology estimated in the study. By 55, men have an average sexual life expectancy of 15 years and women can expect 10 more years, they found, based on data from two separate surveys.

People in very good or excellent health were almost twice as likely to be interested in sex as people in poorer health, according to the study. Men lost more years of sexual activity as a result of poor health than women, the researchers said. That may motivate men to pursue healthier lifestyles, they said.

"Translation of expectations about the duration and quality of sexually active life may, at the individual level, influence important health behaviors to promote or prolong sexual functioning, such as adherence to medical treatment or maintenance of a healthy lifestyle," the researchers wrote.

The team, led by Stacy Tessler Lindau, used data from a 1995-1996 survey of 3,000 men and women between ages 25 and 74 and a 2005-2006 survey of 3,000 men and women between 57 and 85. Men were more likely than women to be sexually active, report a having a good quality sex life and be interested in sex, according to the study.

The gap was largest among 75- to 85-year-olds. About 40 percent of men in that group were sexually active, compared to 17 percent of women, the researchers found.

The study was funded by the University of Chicago and the National Institutes of Health.