LONDON (AP) -- It seems the old cliche may be true.

Men are more likely than women to be interested in sex, have sex and enjoy sex, according to new scientific research, which also found people who stay active and healthy enjoy longer sex lives.

Research by University of Chicago academics published online Wednesday in the British Medical Journal found that, across all age groups, men were more interested in sex than women -- and the gap increased with age.

The difference was most pronounced in the 75 to 85 age group, where 39 percent of men and 17 percent of women said they were sexually active, although the gender difference was smaller among people with a partner. Women of that age are more likely than men to be widowed.

A total of 71 percent of men who were sexually active above age 75 reported a good sex life, compared with 51 percent of women, while 41 percent of men said they were interested in sex, compared to 11 percent of women.

"Overall, men were more likely than women to be sexually active, report a good quality sex life, and be interested in sex," the researchers found.

"This disparity, and its implication for health, requires further exploration."

The researchers found the average person's sex life winds down by the age of 70. It said that by age 55, men can hope for another 15 years while women generally have another 11 years of sexual activity.

But 55-year-old men in very good or excellent health gained five to seven years of sexually active life on average, compared with their peers in poor or fair health. Women in very good or excellent health gained three to six years compared with women in poor or fair health.

The research adds to a pile of scientific evidence suggesting good sex can improve health and well-being -- and vice versa.

The researchers found that, overall, people in very good or excellent health were 1.5 to 1.8 times more likely to report an interest in sex than those in poorer health.

Researchers Stacy Tessler Lindau and Natalia Gavrilova looked at data from two groups of just over 3,000 American men and women -- one aged 25 to 74 and the other aged 57 to 85.

Subjects were interviewed and filled in questionnaires on their marital status, rated the quality of their sex lives and asked how often they had sex. They also rated their health on a scale between poor and excellent.

In an accompanying editorial, Patricia Goodson, a professor of health at Texas A&M University, said the study was "refreshing because it offers a health enhancing, health promoting perspective. ... The news that adults in the U.S. can enjoy many years of sexual activity beyond age 55 is promising."

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