London, Sep 10 : Researchers have said that as the age increases, the number of sexual partners changes, a new study has found. According to the study by the University of East Anglia (UEA), in collaboration with King's College London and University College London, many gay and bisexual men over age 70 continue to have a sex life with multiple partners, while straight women become less sexually active after age 50. "Before this study, many models about sexually transmitted diseases assumed that everyone over a certain age - say 40 or 65 - stopped being sexually active, or at least stopped having multiple partners," said Dr Julii Brainard, from UEA's Norwich Medical School. The study is based on a survey of 5,164 British people, 3,297 of whom were drawn from the general population and 1,036 of whom were recruited via Facebook and Instagram. An additional 831 people responded to advertisements on the LGBTQ dating app Grindr. The researchers focused on the relationship between sex partner counts in the last three weeks and respondent age, using statistical models to see how much a person's age was linked to their recent partner count. According to the study, most people had either zero or one sexual partner at any age in the preceding three weeks. About 65 per cent of heterosexual women reported having one partner in the last three weeks consistently until they were 50 - after which there was a steep climb in reporting no partners. Nearly 79 per cent of women aged over 70 who identified as heterosexual or had any male partners in the last three months, had no male partners in the last three weeks. Moreover, the study showed that about 50 per cent of heterosexual men reported having one partner in the last three weeks. But they were increasingly likely to report no partners as they got older. About 50 per cent of men aged over 70 who were heterosexual or had sex with any women in the last three months, didn't have a female partner in the most recent three weeks, compared to just 44 per cent of men having heterosexual sex who had no recent female partners when age under 70. Only two per cent of straight people over 70 reported multiple partners. "We managed to collect a lot of data from MSM who practised partner concurrency. About 45 per cent of them sustained partner concurrency from age 27 to 63. Even at age 65+, the respondents recruited via social media still tended to have more sexual contact than the general population sample at the same age," Brainard said. /IANS