Men in same-sex marriages are living longer Death rate for men in same-sex marriages has dropped markedly since the 1990s, Danish research shows But women in same-sex marriages have emerged as the group with the highest mortality Increased risk of cancer and suicide in female couples Gay men in same-sex marriages are living longer - but the same cannot be said for their female counterparts, according to new research. A Danish study has revealed that the death rate for men in same-sex marriages has dropped markedly since the 1990s, yet women in same-sex marriages have emerged as the group with the highest mortality. They are more likely to die at a relatively young age as they are more likely to commit suicide or succumb to cancer, the researchers said. The death rate for men in same-sex marriages has dropped markedly since the 1990s Denmark implemented the world's first national law on registered same-sex partnerships in 1989. Mortality was markedly elevated among people in same-sex marriages for the first several years after, but since 1996, with the advent of effective treatment for HIV/AIDS, mortality among men married to men has dropped to a level below that of unmarried or divorced men. In contrast, the study also found that women married to women were at increased risk of mortality, most notably from suicide and cancer. Study leader author Morten Frisch, from Statens Serum Institut, Copenhagen, said: 'Lesbians may constitute a largely unnoticed high-risk population for suicide and breast cancer, so our findings call for efforts to identify the underlying factors responsible and ensure access to basic health care in this population.' Dr Frisch and statistician Jacob Simonsen used Denmark's Civil Registration System to follow 6.5 million adults who lived in Denmark for any period between January 1st, 1982, and September 30th, 2011. In contrast, the study found that women married to women were at increased risk of death, most notably from breast cancer (pictured) and suicide The most marked changes in mortality were seen among same-sex married persons. Between 2000 and 2011, same-sex married Danish women emerged as a group with particularly increased mortality. Marriage has long been known to be associated with a reduced risk of an early death and the research confirmed that being married to or living with someone of the opposite sex was the best way to live longer. But they added that there have been big changes in the marital status of Western populations over the past decades. While the proportion of people married to members of the opposite sex has declined, there has been an increase in the proportions of single and divorced people. However, being married itself isn't enough. Married couples who didn't live together didn't get the same benefits - in fact, they were twice as likely to die as those who lived with their spouse, the study reported. Dr Frisch added: 'It is a novel observation that being married was not always protective.' The findings were published in the International Journal of Epidemiology.