There are certain subjects – GM, nuclear power, climate change – that cause aeration in scientific circles. And, as president elect of the American College of Surgeons Lazar Greenfield found out recently, the reputed antidepressant effects of semen are also a subject to be treated with care.

In his Valentine's Day-themed editorial in Surgery News, "Gut Feelings", Lazar cited a study that reported the mood-boosting effects of semen on women, concluding: "So there's a deeper bond between men and women than St Valentine would have suspected, and now we know there's a better gift for that day than chocolate."

Greenfield's Andy Gray moment offended many ACS members and he was accused of sexism; demonstrations were threatened. Greenfield is a highly respected retired professor emeritus of surgery at the University of Michigan with what has been described as "a reputation for supporting women in surgery" and he is also the inventor of the Greenfield Filter, a device that prevents blood clots.

Confronted with the furore he'd caused, Greenfield apologised and gave up his editorship of Surgery News. Two weeks ago the controversy over what had become known as "Semengate" hadn't gone away, so he also resigned from his ACS position.

Greenfield told the Detroit Free Press: "I was short-sighted in not anticipating the potential for my remark to be misinterpreted… I thought [these were] fascinating new findings related to semen, and the way in which nature is trying to promote a stronger bond between men and women. It impressed me. It seemed as though it was a gift from nature. And so that was the reason for my lighthearted comments."

The study he was referring to was in fact published back in 2002 by Gordon Gallup, a psychologist at SUNY-Albany. His team found that women whose partners didn't use condoms were less depressed. They also found that depressive symptoms and suicide attempts were higher among women who used condoms regularly compared to those who didn't. Moreover, the women who didn't use condoms became more depressed the longer they went without having sex. Gallup suggested this was because semen contains oestrogen and prostaglandins which have been linked to lower levels of depression, and oxytocin which promotes social bonding.

Gallup's study came with an important caveat: "I want to make it clear that we are not advocating that people abstain from using condoms. Clearly an unwanted pregnancy or a sexually transmitted disease would more than offset any advantageous psychological effects of semen."

Last week, his research back in the news, Gallup elaborated to Popular Science: "Seminal plasma evolved to control and manipulate the female reproductive system so as to work toward the best interests of the donor – the male." He suggested that the possible antidepressant properties of semen may promote bonding between the sexual partners, and that was to the male's reproductive advantage.

Asked about the controversy Greenfield's remarks had caused, Gallup commented: "I think it's a tragic overreaction. The point at which we begin to let political agenda dictate what science is all about is the point when science ceases to be a viable enterprise."