On semen

From The Huffington Post

Lazar Greenfield, M.D. is no ordinary surgeon. Until last week, he was the president-elect of the American College of Surgeons. The man is the inventor of the Greenfield Filter, a device that has saved countless lives as a means of preventing blood clots during surgery. He's a professor emeritus of surgery at the University of Michigan. He has written more than 360 scientific articles in peer-reviewed journals, 128 book chapters and two textbooks. He has served on the Editorial Board of 15 scientific journals and was also the lead editor of the Surgery News, the trade publication in which his writing initiated Semengate.

In the February issue, he penned some thoughts on Valentine's Day under the heading of "Gut Feelings." ("But Valentine's Day is about love, and if you remember a romantic gut feeling when you met your significant other, it might have a physiological basis.") Greenfield proceeded to then discuss the mating habits of fruit flies ("It has long been known that Drosophila raised on starch media are more likely to mate with other starch-raised flies"), the mating habits of the rotifer ("Biologists say that it's more advantageous for a rotifer to remain asexual and pass 100 percent of its genetic information to the next generation."). In each case, Dr. Greenfield made sure to reference to the scientific literature. Then he turned his attention to humans.

Dr. Greenfield noted the therapeutic effects of semen, citing research from the Archives of Sexual Behavior which found that female college students practicing unprotected sex were less likely to suffer from depression than those whose partners used condoms (as well as those who remained abstinent).

Presumably it was the closing line that caused the controversy: "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 chocolates."

The attempt at Jackie Mason-humor apparently didn't sit well in certain quarters. Dr. Greenfield resigned as editor of the Surgery News and gave up his stewardship of ACS after learning that his article had spurred threats of protests from outside women's groups.

In an interview with the Detroit Free Press last Wednesday, Dr. Greenfield explained:

The editorial was a review of what I thought was some 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 story has been big in the scientific community, but in all that has been printed, there is one take I thought missing and noteworthy -- that of the three psychologists who authored the peer-reviewed article cited by Dr. Greenfield. So I tracked down Steven M. Platek, Rebecca L. Burch, and Gordon G. Gallup, Jr.

Speaking for the group, Dr. Steven M. Platek, Ph.D, the editor-in-chief of Frontiers in Evolutionary Neuroscience and a co-editor of Evolutionary Psychology, offered this analysis:

Frankly, we think people are over reacting to the comments made by Dr. Lazar Greenfield. There is growing evidence that human semen has the potential to produce profound effects on women. We have replicated the effects showing female college students having sex without condoms are less depressed as measured by objective scores on the Beck Depression Inventory. We've also examined the data as a function of whether the students were using hormonal contraceptives, whether they were in committed relationships, and how long these relationships have lasted. The anti-depressant properties of semen exposure do not vary as function of any of these conditions. It is not a question of whether females are sexually active, since students having sex with condoms show the same level of depression as those who are not having sex at all. We have also received numerous semen testimonials from other women who attest to the anti-depressant effects of semen exposure and these accounts often include the use of control trials (i.e., comparisons generated by switching from condoms to unprotected sex, or vice a versa).
Only 5 percent of the ejaculate is sperm. What's left is seminal plasma, which is a rich concoction of chemicals, including many that have the potential to produce mood-altering effects derived from hormones, neurotransmitters, and endorphins. There are even female sex hormones in male semen. Within a hour or two after insemination, you can detect heightened levels of many of these seminal chemicals in a woman's bloodstream.

But it is also important to acknowledge that there is a dark side to semen chemistry. The vagina is a very hostile environment for sperm. During human evolutionary history women couldn't afford to conceive as a consequence of being inseminated by just any man, and the presence of semen in the female reproductive tract often triggers an immune reaction that treats the sperm as a pathogen. Not surprisingly, semen chemistry has evolved to neutralize vaginal acidity and suppress the woman's immune system. There is even reason to believe that because of the immunosuppressant properties of semen, frequent insemination may compromise the female immune system. Because there are female as well as male sex hormones in human semen, there are other reasons to believe that additional features of semen evolved to promote the reproductive best interests of the donor. The presence of follicle stimulating hormone and leutenizing hormone in semen, implies that semen exposure has the potential to promote induced ovulation.

How can someone be asked to resign for citing a peer-reviewed paper? Dr. Greenfield was forced to resign based on politics, not evidence. His resignation is more a reflection of the feminist and anti-scientific attitudes of some self-righteous and indignant members of the American College of Surgeons. Science is based on evidence, not politics. In science knowing is always preferable to not knowing.

Steven M. Platek
Rebecca L. Burch
Gordon G. Gallup, Jr.