GAY campaigners have condemned a study by a Scottish-based academic that claims only straight sex benefits people’s physical and emotional health.

Stuart Brody, professor of psychology at Paisley University, claims that intercourse between men and women is the only form of sexual behaviour that improves “psychological and physiological function”.

His findings, which challenge the widely held belief that all forms of safe sex between consenting adults are equally beneficial, have provoked anger among the gay community.

Peter Tatchell, the gay rights campaigner, accused Brody of promoting an “unscientific and extreme” agenda that flies in the face of previous studies.

Brody examined the stress levels of 46 men and women after they had engaged in various forms of sexual activity.

According to the American academic’s findings, those who had engaged in “straight” intercourse were least stressed and their blood pressure returned to normal faster than any of the other volunteers.

Brody claimed levels of prolactin, the hormone that provides the body with sexual gratification, were 400% higher among male and female couples who had heterosexual intercourse. Those who abstained from sex had the highest blood pressure response to stress.

According to his study, the effects could not be attributed to other stress-related factors such as work, anxiety or the quality of the relationships, and they were valid for both men and women.

However, Tatchell said Brody’s findings were “flatly contradicted” by a 14-year study carried out by the renowned American sex researchers William Masters and Virginia Johnson.

“Their study found that levels of physical and emotional satisfaction during and after sex were almost identical for both heterosexual and homosexual couples,” he said.

“The sample in the Masters and Johnson survey was infinitely larger and their methodology was widely peer-reviewed and validated.

“Brody’s is an extreme and disparaging stance to adopt and he seems to have an ideological agenda to promote conventional heterosexual intercourse.”

While Brody conceded that his findings were not “politically correct”, he insisted that the physical and emotional rewards associated with intercourse between men and women are the result of human evolution and the natural drive to reproduce.

“I wasn’t surprised by my findings at all,” he said. “There are many reasons why it should be so. Evolution is not politically correct. It strongly rewards any behaviour which has even a trivial association with an increasing likelihood of passing on genes.”

“The radical left wants sex research done, but only if the results are politically acceptable to them,” he added. “I have met a lot of homosexual men who have a great interest in truth, but there will always be some people who put maintenance of their ideology above science.”

Brody, who is in a heterosexual relationship, added that the long-standing claim that all forms of sexual behaviour confer the same health benefits was based on political ideology rather than scientific fact.

“Since the time of (Alfred) Kinsey (the American biologist who studied human sexuality during the 1940s and 1950s) it has been asserted but never supported by evidence that all sexual behaviour is equivalent,” he said. “That has been more an assertion of ideology than fact.

“I have been measuring with hard variables, such as blood pressure and hormone levels, as well as softer variables, such as psychological reports, the differences between major categories of sexual behaviour.”

He also criticised the “religious right” for attempting to twist his research for its own purposes and denied that he was discriminatory against same-sex relations.

“I am in favour of people being made aware of the relative benefits (of different forms of intercourse) and then they can live their lives as they choose,” he said.

Oliver Wright of the Terrence Higgins Trust, a charity which campaigns to improve the health of gay men, claimed Brody’s stance was controversial and had “raised eyebrows”.

In 1998 Tatchell disrupted the Easter sermon by George Carey, the Archbishop of Canterbury, mounting the pulpit to denounce Carey’s alleged discrimination against lesbians and gay men.

In 2001 the activist was beaten by the bodyguards of Zimbabwean President Robert Mugabe after he attempted to perform a citizen’s arrest on the despot.

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