Lesbians, gay men and bisexuals who are out have lower stress hormones than those who hide their sexuality, according to a study in Canada.

Researchers at the Centre for Studies on Human Stress (CSHS) Louis H Lafontaine Hospital, affiliated with the University of Montreal, tested the levels of cortisol – a stress hormone – and other indicators of strain in gay people, bisexuals and heterosexuals.

The researchers surveyed 87 men and women, all around age 25, administering psychological questionnaires and taking blood, saliva and urine samples to measure stress.

“Our goals were to determine if the mental and physical health of lesbians, gay men and bisexuals differs from heterosexuals and, if so, whether being out of the closet makes a difference,” lead author Robert-Paul Juster said to AFP.

“We used measures of psychiatric symptoms, cortisol levels throughout the day, and a battery of over twenty biological markers to assess allostatic load.”

Speaking of the results, Mr Juster said: “Contrary to our expectations, gay and bisexual men had lower depressive symptoms and allostatic load levels (a measure of body stress) than heterosexual men.”

He added: “Lesbians, gay men, and bisexuals who were out to family and friends had lower levels of psychiatric symptoms and lower morning cortisol levels than those who were still in the closet.”

Sonia Lupien, director of the CSHS, said testing stress levels can help to detect people at risk of health problems: “Chronic stress and misbalanced cortisol levels can exert a kind of domino effect on connected biological systems.

“By looking at biomarkers like insulin, sugar, cholesterol, blood pressure, adrenalin, and inflammation together, an allostatic load index can be constructed and then used to detect health problems before they occur.”