A study in the March issue of the ‘Journal of Health and Social Behavior’ says same-sex cohabitors are less healthy than heterosexual married people of the same socioeconomic status - however same-sex marriage “may directly and indirectly influence the health of individuals in same-sex unions”.

The lead author of the study and assistant professor of sociology at Michigan State University, Hui Liu claims that married people are “generally healthier”, reports Science Daily.

She said: “Past research has shown that married people are generally healthier than unmarried people.

“Although our study did not specifically test the health consequences of legalising same-sex marriage, it’s very plausible that legalisation of gay marriage would reduce health disparities between same-sex cohabitors and married heterosexuals.”

The study used American data from the 1997 to 2009 National Health Interview Survey (NHIS) involving white, black and Hispanic 18 to 65-year-olds and compared the self-rated health of 1,659 same-sex cohabiting men and 1,634 same-sex cohabiting women with different-sex married, different-sex cohabiting, unpartnered, divorced, widowed and never married people.

“When we controlled for socioeconomic status, the odds of reporting poor or fair health were about 61 percent higher for same-sex cohabiting men than for men in heterosexual marriages and the odds of reporting poor or fair health were about 46 percent higher for same-sex cohabiting women than for women in heterosexual marriages,” Liu said.

Liu suspects “higher levels of stress and discrimination” for same-sex cohabitors identifying as less healthy.

She said: “Research consistently suggests that ‘out’ sexual minorities experience heightened levels of stress and higher levels of discrimination, and these experiences may adversely affect the health of this population.

“It may also be that same-sex cohabitation does not provide the same psychosocial, socioeconomic, and institutional resources that come with legal marriage, factors that are theorized to be responsible for many of the health benefits of marriage.”

According to the study, providing same-sex cohabitors the option to marry may boost their measures of self-rated health because they would have higher levels of acceptance and lower levels of stigma.

Ms Liu added: “Legalising same-sex marriage could also provide other advantages often associated with heterosexual marriage - such as partner health insurance benefits and the ability to file joint tax returns - that may directly and indirectly influence the health of individuals in same-sex unions.”