The Nation - Sex is a gray area, study says - Barring health issues or the lack of a partner, many Americans remain sexually active well into old age, a survey of 3,005 adults finds.

The study of 3,005 adults ages 57 to 85 found the majority had an active sex life. More than half of sexually active older adults had sex two to three times a month -- the same frequency reported among younger adults in a large 1992 national survey.

The report, in the New England Journal of Medicine, found passions cooled as people aged, but said the declining interest in sex couldn't be attributed to age alone.

A shortage of older men prevented many women in their 70s and 80s from hooking up, researchers said.

In addition, older adults with health problems were far less sexually active.

Participants in the study were considered sexually active if they had any sort of sexual contact with someone else in the preceding 12 months.

The nationwide study is the most comprehensive look yet at sexual activity among older Americans, an area that has received little scientific attention. Researchers said they hoped the findings would dispel commonly held notions that people lose all interest in sex as they age, and that sex is the province of the young.

"Older people are just younger people later in life," said lead author Dr. Stacy Tessler Lindau, a gynecologist at the University of Chicago Pritzker School of Medicine.

Still, Lindau cautioned the study wasn't meant to set a standard for normal sexual behavior that older people should feel compelled to achieve despite their personal preferences or circumstances.

"Certainly many people make a choice not to be sexually active," she said.

The study, funded by the National Institutes of Health, examined the nature and frequency of sexual activity among older adults, including the prevalence of such performance problems as sexual dysfunction. Subjects were interviewed about their sexual practices and researchers also collected information on participants' overall health and intimate relationships.

Subjects were divided into three age groups for the purpose of analysis.

Nearly three-quarters of adults ages 57 to 64 were sexually active compared with about one-quarter of adults ages 75 to 85, the report found. About half of adults ages 65 to 74 were sexually active.