Sperm Apocalypse Called Off

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Woody is not alone

The latest research suggests that guys can relax about the state of their swimmers. One of more popular scares of the 1990s was the threat that environmental estrogens allegedly posed to male fertility. The idea is that various man-made substances act like estrogen in the human body and were possibly responsible for as much as a 50 percent average decline in sperm counts since the World War II. One of the groups reporting this alarming trend was led by Danish researcher Niels Skakkebaek.This concern was hyped in the 1996 environmentalist screed Our Stolen Future: Are We Threatening Our Ferility, Intelligence, and Survival?—A Scientific Detective Story by activsts Theo Colborn, Dianne Dumanoski, and John Peterson Myers.

Back in 1996, I wrote an op/ed, "Hormones and Humbug: A New Expose is One Part Pseudo-Science, Two Parts Hype, Three Parts Hysteria" for the Washington Post analyzing the claims made in Our Stolen Future. Here's some of what I reported:

Like most thrillers, "Our Stolen Future" is based on a little bit of fact and a whole lot of imagination.

Are these synthetic chemicals really causing hormonal harm? Most scientists don't think so. John Giesy, a professor of toxicology at Michigan State University and past president of the Society of Environmental Toxicology and Chemistry, says, "Frankly, Colborn doesn't know very much. She reads the entire literature and picks and chooses things that support her preconceived views."

Stephen Safe, a professor at Texas A&M University and a leading expert on environmental estrogens, agrees: "If you look at the book carefully, it's a very unscientific presentation."

The first thing that must be noted is that we are exposed to vastly greater quantities of natural estrogens than we are to synthetic estrogens. Why? Because common food plants like soybeans, corn, wheat, broccoli and kidney beans are loaded with natural estrogens. People eat 40 million times more natural plant estrogens than they do synthetic estrogens each day. Synthetic estrogens are thousands to millions of times weaker than the estrogen produced by the body. Colborn acknowledges this but suggests that synthetics are more pernicious "because they can persist in the body for years, while plant estrogens might be eliminated within a day."

Like so much of "Our Stolen Future," this is true, but misleading. Giesy points out that estrogen compounds must be circulating in the blood to have an effect. And even if the body does eliminate plant estrogens daily, each meal replenishes the amount circulating in our blood. In fact, synthetics are generally inactive because they are stored in the body's fat cells. More importantly, the levels of the chemicals that worry the authors have been dropping for decades. For example, background DDT levels in the United States are only one-15th to one-20th of what they were in the 1970s. As for PCB levels, they have also declined. In 1972, 61 percent of Americans had 1 part per million of PCB in their fat tissues; by 1983, only 6 percent did.

The most sensational assertion in "Our Stolen Future" is that human sperm counts have fallen by 50 percent in the last 50 years, a trend that the authors suggest may jeopardize the very future of the human race. This claim is largely based on an analysis of 61 studies by Danish scientist Niels Skakkebaek and his colleagues. Most fertility specialists regard Skakkebaek's study as severely flawed. Among other things, he did not take into account regional differences, age differences and ethnic differences in sperm donors. Last November, Dr. Larry Lipshultz, professor of urology at Baylor College of Medicine, co-chaired a "consensus meeting" attended by leading fertility researchers including Skakkebaek. "We reviewed all available data and concluded that you really cannot use these data to draw the conclusions that Colborn has drawn about trends in the quality of human semen," says Lipshultz.

A forthcoming study in the scholarly journal Fertility and Sterility further undercuts the notion that sperm counts are declining. Dr. Harry Fisch, who heads the male reproductive center at Columbia Presbyterian Hospital in New York, looked at trends in sperm counts in New York City, Minnesota and Los Angeles and found that there has been no nationwide change in semen quality in the last 25 years. In another study, researchers in Wisconsin found no change over a 10-year period.

Colborn also suggests that infertility is increasing in the United States. But it's not so. Dr. Richard Sherins of the Genetics and IVF Institute in Fairfax wrote in the New England Journal of Medicine that "rates of infertility have remained constant during the past three decades (at 8 to 11 percent), and male infertility has accounted for approximately one-third of the cases." …

Baylor College of Medicine's Lipshultz puts it succinctly when he says that, "Something is missing in 'Our Stolen Future' and that's called science." He adds, "The book is going to frighten a lot of people and that's unfair."

Striving for some brevity, I will not cite the section of my op/ed in which I debunked the claim that environmental estrogens were responsible for increasing cancer rates.

Nearly twenty-five years after this book helped launch numerous regulations, new data is showing that with respect to claims about a sperm apocalypse the environmental estrogen hypothesis turns out to be exaggerated. In today's New York Times, Gina Kolata reports:

It is one of the most fraught topics in environmental health. Are men becoming less fertile, with declining sperm counts and diminishing sperm quality? If they are, then sperm might be an early warning sign of environmental dangers. And the prime suspects have been substances like plastics and pesticides that can have weak estrogenlike effects on cells.

But now 15 years of data from 18-year-old Danish men taking their military physicals show no decline in sperm counts, after all. The idea that sperm counts were plummeting began with an alarming paper published in 1992 by a group of Danish researchers. Sperm counts, they reported, declined by 50 percent worldwide from 1938 to 1991, and the trend would continue, they said.

Many other researchers criticized the data's quality, citing flaws like a lack of standardized methods of collecting semen, methodological issues in semen analysis, biases in the ways men were selected, and variations in the length of time men abstained from ejaculating before their semen was collected.

The study, said Dolores Lamb, a fertility expert at Baylor College of Medicine and president-elect of the American Society of Reproductive Medicine, "was problematic and raised alarms in society without critical thinking about the caveats and weaknesses inherent in the data and its analysis."

Nonetheless, the paper was highly influential. It was cited by 1,000 subsequent scientific papers.

So what does the new Danish study (downloadable here) find:

Healthy 18-year-old men who attend a compulsory examination of fitness for military service in 2 Danish cities are encouraged to provide semen and blood samples. Each year, from 16% to 30% have agreed, and a total of 5000 men have provided semen samples. These data were publicly presented for the first time in March of this year, when they were posted on a government agency Web site by the Danish National Board of Health. These data provide no indication that semen quality has changed during the past 15 years (Fig.). Throughout the years of surveillance, the crude median sperm concentration has fluctuated around a median value of 40 – 45 million/mL, with the lowest value (35 million/mL) in 2006 and the highest (50 million/mL) in 2007.

No decline since 1996. The researchers are appropriately cautious and do note that "the proportion of young men with low sperm counts is surprisingly large." However, they point out:

How do the new findings fit with concerns regarding environmental effects on male reproduction? A substantial research effort in the past 15 years has uncovered numerous environmental chemicals that weakly interfere with endoge- nous hormonal regulation through a variety of mechanisms related to steroid receptors and various enzymes. The estrogen hypothesis proposed in the early 1990s has been largely abandoned by one of its fathers, and is not supported by a wide range of epidemiologic data. Meanwhile, there is only very limited epidemiologic evidence to support the broader endocrine disruption hypothesis (delayed effects on the male reproductive system following imbalance of estrogenic and androgenic actions in early fetal life, for instance, as might be caused by phthalate exposure).

So if environmental estrogens are unlikely culprits, what could account for some young men having relatively low sperm counts? The researchers suggest that the recent increase in obesity might be a contributor.

Interestingly, Skakkabaek is one of the lead researchers on this new study and has apparently been reluctant release these findings.

Whole New York Times article can be found here.

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94 responses to “Sperm Apocalypse Called Off

  1. Nearly twenty-five years after this book helped launch numerous regulations, new data is showing that with respect to claims about a sperm apocalypse the environmental estrogen hypothesis turns out to be exaggerated.

    Puts on *shocked* face.

    1. I’m aghast as well. Everybody knows that it should be “new data are…”

      1. Ron’s an American, not a Brit.

    2. So obviously, all those new regulations will be rolled back, right? Right?? Isn’t that how things work???

  2. Woody Allen is an American treasure. I loved that skit.

    I hope his new film with Owen Wilson is more like Manhattan and Annie Hall and less like his last couple post-Match Point films.

    1. Woody Allen is an overrated hack with an Asian fetish. Yeah, I said it. He’s been going downhill since What’s Up Tiger Lily and Annie Hall is self-indulgent garbage.

      1. I like his earlier, funnier movies.

        1. Which were those?

          1. Bananas was pretty good, so was Sleeper.

          2. Well, definitely Bananas, Sleeper, and Love and Death. I also like Annie Hall–don’t forget it has a very early Walken–and a few of his later films. But the earlier ones are his best.

            1. Annie Hall is one of the most overrated pieces of shit of all time. I cannot believe the number of people whose taste I respect that claim to like that movie, yet when pressed, they can’t give specifics of what they like about it. And if you say that it’s Diane Keaton, you’re fucking dead to me. DEAD.

              1. I like the scene where he is in line for the movie with the loud talker behind him. That one scene is golden, makes the whole movie good.

                1. You know nothing of my work!

              2. I like bits and pieces of it. It’s not as good as his earlier stuff. . .not to me, anyway. The scene with her family (that’s got the Walken) is one of my favorites.

                It’s self-indulgent–I agree–but I don’t think it’s crap. However, I think it was the beginning of his decline.

              3. Are you kidding me? The scene in the classroom where the kids are talking about their future is funny as hell.

                I also like it when Woody Allen is watching people in the park and making comments about them, funny to.

                Not to mention the scene with the cocaine where he sneezes and blows white powder everywhere.

                http://libertarians4freedom.blogspot.com/

              4. Annie Hall has the scene where Woody delivers the Dead Shark speech, and that alone means it contributed more to the analysis of human relationships than the work of any ten other men.

                1. I tend to think Crimes and Misdemeanors is quite good, as is Mighty Aphrodite. It’s not ONLY Allen’s really early work that’s good.

            2. Love and Death is my favorite WA movie.

              It’s funny on different levels – the mockery of certain Russian novels, the French jokes, and some good anti-intellectual jabs.

              1. Probably my favorite as well.

      2. Annie Hall is a masterwork.

        Ebert on the film:

        Consider Allen’s astonishing range of visual tactics, including split screens in which the characters on either side directly address one another; a bedroom scene where Annie’s spirit gets up during sex to sit, bored, in a chair by the bed; autobiographical flashbacks; subtitles that reveal what characters are really thinking; children who address us as if they were adults (“I’m into leather”); an animated sequence pairing Alvy with Snow White’s wicked witch; and the way Alvy speaks directly out of the screen to the audience.

        1. but it does have the nasty side effect of reducing sperm count.

        2. All, true, but “Cinematic Masterwork” does not equal “good film”.

          It is a masterfully-shot-and-produced, mediocre movie.

  3. crude median sperm concentration has fluctuated around a median value of 40 ? 45 million/mL, with the lowest value (35 million/mL) in 2006 and the highest (50 million/mL) in 2007.

    So, Danish male children born the year after Reagan left office produce 40% more sperm than those born before he left office. Obviously another reason to hate Reagan.

    /tin foil hat mode

    1. So much for the trickle down effect.

    2. Dey tuuk are sperms!

  4. because every sperm is sacred.

  5. Yet another data point to the hypothesis that the best way to become a world renowned and famous geek in a lab coat is to dream up the most horrifically scary concept that’s actually as far from the truth as possible, and successfully market that into a full blown public panic. They truly rank each other by who had the dumbest laws passed as a reaction to their fairy tales, when they should be awarded a prize that includes an honorary dunce cap, to alert everyone else that they’re walking, talking morons that use big words.

    1. Yet another data point to the hypothesis that the best way to become a world renowned and famous geek in a lab coat is to dream up the most horrifically scary concept that’s actually as far from the truth as possible, and successfully market that into a full blown public panic.

      Shit you cracked the code! Now you must be eliminated!

  6. If men aren’t becoming less manly, how do you explain Shia LeBeouf as an action hero?

    1. Remember: This is the same Hollywood that sold us Sarah Jessica Parker as a sex symbol. Neigh.

      1. She looks like a horse.

        1. So did Mr. Ed.

  7. “Frankly, Colborn doesn’t know very much. She reads the entire literature and picks and chooses things that support her preconceived views.”

    Souds like science and politics are simpatico

    1. Don’t ruin our thread with your vile presence, rectal. Just go away. Forever.

      1. Such hatred between the two, the sex would be incredible.

    2. I know Theo. She won’t fuck you either.

  8. Be aware that Enraged Cock’s new black metal concept album “Sperm Apocalypse” is still scheduled for a summer release. It completes the trilogy after “My Taint Defiled” and “Scrotal Trauma Symphony.”

  9. Danish basic training is the coolest thing evar!

  10. The new study has plenty of methodological flaws. Don’t think it’s dispositive; the conclusion that “environmental estrogens don’t affect sperm counts” can’t be drawn from this VERY limited dataset.

    As I posted in another thread a few days ago, epidemiological analysis is inherently noisy. We can’t really run controlled experiments on populations and there are always more confounders than we can know about. How long did it take before tobacco/cancer was really nailed down (and that was a much easier one)?

    disclaimer: I do research in this subject for a living.

    1. OMWC: No study is dispositive, yet the original Skakkebaek study was used to launch this “scare.” See John P. A. Ioannidis’ article “An Epidemic of False Positives” at Scientific American for some cautionary words on the use of epidemiology in public policy.

      1. And yet, one reads your blog entry here which uses terms like “humbug,” “pseudoscience,” “scare” in scare quotes(!), “debunked,” and it is impossible to come away with any idea other than “this is all bullshit and been disproved.” That is utterly false. Saying that “people have not yet definitively proved their assertions and there’s a lot of conflicting evidence” is not the same thing as “the assertions have been demonstrated to be incorrect.”

        Public policy is a different issue, and as a libertarian, I generally find myself on the opposite side from my colleagues and peers. But that does not mean that their science is wrong or that mine is, it means that we have very different views about regulation and the role of government.

        1. And yet, one reads your blog entry here which uses terms like “humbug,” “pseudoscience,” “scare” in scare quotes(!), “debunked,” and it is impossible to come away with any idea other than “this is all bullshit and been disproved.” That is utterly false.

          Ron’s job is to provide rhetorical fuel to promote a certain ideology. The truth is only tangentially relevant in that context.

          1. OMWC & NM: Before calling ideology on someone, I hope you’ve checked your own confirmation biases. I know that I have. You might also be interested in my WSJ review of epidemiologist Geoffrey Kabat’s book, Hyping Health Risks. It’s a good premier on how epidemiology is abused by ideologues like Colborn et al.

            1. *primer*

        2. Here’s the problem:

          If you’re correct that even something really, really obvious even as long ago as the time of King James (“Cigarette smoke is bad for you”) is extraordinarily hard to prove epidemiologically, that to me says that proving something much more obscure should be categorically impossible.

          If it’s that difficult to do, then the original paper should never have been given any credence to begin with.

          1. Fluffy, you ignorant slut. There’s actually a fairly rich literature, including in vivo and in vitro data to address proposed mechanisms, as well as the two epidemiology papers (that’s many, many more). The tobacco-cancer link is quite a bit more recent than King James, but the 40 years or so that it took to get the data solidified is not unusual for epidemiology. What makes EDC research tougher is that it often involves development rather than gross effects, is highly confounded by demographic, and is studied amidst a pervasive and increasing background of environmental xenoestrogens and increasing consumption of phytoestrogens (will tofu instead of steak turn you into a big-moobed pussy?).

            Anyone who implies that the science is settled is full of shit.

  11. I would bet this is another scare which scientists take advantage of by producing questionable statistics to get more funding.

    Until we have scenario like in the “Children of Men” book, I see this sperm scare as yet another lame attempt to blame the industrial revolution for the worlds problems.

  12. “So if environmental estrogens are unlikely culprits, what could account for some young men having relatively low sperm counts? The researchers suggest that the recent increase in obesity might be a contributor.”

    It’s interesting that obesity would be a concern of those actively trying to enroll in the military as those were the sample sources. You would figure the majority of those looking to enlist would be in at least adequate shape. I guess I’ll have to look into the research to see what the correlation between obesity and sperm count was.

    1. Another interesting question is whether or not xenoestrogens could indirectly cause reduced sperm counts by making people more susceptible to obesity. Confounders everywhere!

    2. All Danish men are required to be tested (“a compulsory examination of fitness for military service in 2 Danish cities”), so the sample should be representative of the population.

      1. *Required to be tested since military service in Denmark is mandatory.

        1. While it’s true that “[a]ll Danish men are required to be tested”, according to the post, the actual taking of sperm samples in voluntary and compliance has varied between 16% and 30%.

          Healthy 18-year-old men who attend a compulsory examination of fitness for military service in 2 Danish cities are encouraged to provide semen and blood samples. Each year, from 16% to 30% have agreed, and a total of 5000 men have provided semen samples.

          Until I got to that section, I was thinking, “man, I knew the Danes were weird, but a semen sample at your draft physical? What kind of duties are they expecting from their soldiers?” 🙂

          1. Technically, raping and pillaging are still part of the requirements for Danish military service. The government prefers fruitful rapes to help propagate the Danish genome.

            1. Good one. That actually made me laugh out loud. For several minutes.

            2. Have to preserve that Viking heritage after all.

              1. If you think about it, Viking genes are all over the place. All those raids, not to mention the occupations, were very successful from the procreation point of view. Shoot, I must have a decent amount of Viking blood, being predominantly German and Scottish. Which explains these urges I have to raid coastal villages.

      2. I thought this might be the case, but when it said between 16-30% of subjects consented to the sample for about 5,000 samples per year it just seemed odd to me that there were only between 17000- 32000 danes coming of age every year.
        Obviously I was too lazy to look into the demographics or population size.

  13. “Stephen Safe, a professor at Texas A&M University and a leading expert on environmental estrogens, agrees: “If you look at the book carefully, it’s a very unscientific presentation.”

    I wonder how many bad puns this poor guy is subjected to.

    1. Well, if I were on the faculty there, every time he knocked on a door, I’d call out (in a German accent), “Is it Safe?” Ditto for any phone calls.

  14. From

    as much as a 50 percent average decline in sperm counts since the World War II

    to

    no nationwide change in semen quality in the last 25 years.

    Resulting in

    No decline since 1996. The researchers are appropriately cautious and do note that “the proportion of young men with low sperm counts is surprisingly large

    is a science reporting word game. Sperm is declining but not since 1996. We know shit about why but we don’t like the other guys view

    1. rather: Did you read the part in which other researchers argue that the meta-analysis on which the 50% decline claim was made was severely flawed?

      The new study is prospective study with relatively well-defined protocols which is why its results are more believable.

      1. Yes, I did. I don’t believe the 50% decline figure but I sure as hell don’t believe the “No decline” couched with “since 1996”

        The question remains why is there a decline? Nutrition, health care, ‘X’ should keep sperm levels immutable, if not a meliorated fertility rate

        1. If we have no data set to support one of these conclusions and exclude the others, what’s your basis for believing in any decline at all?

          1. No decline since 1996. The researchers are appropriately cautious and do note that “the proportion of young men with low sperm counts is surprisingly large.”

            Fluffy, the decline is not in dispute but the time period, and % is in question. The cause is yet to be established but pesticides have long been considered the culprit.

      2. Don’t bother, Ron.

        rather likes to compare apples to pencils.

  15. If environmental estrogens don’t have an effect why do women have much bigger breasts these days?

    1. Fat. Basically women now have man-boobs in addition to woman-boobs. Hermaphrodite boobs.

      1. Not fat, but silicon.

        1. There aren’t enough boobs jobs being done to push the average cup size up to DD.

      2. I imagine implants skew statistics too. Moobies are a more serious repercussion of estrogen than sperm count anyway.

    2. They also have less pubic hair. Obviously this is some kind of hormonal conspiracy.

    3. A final, and far more terrifying, explanation is that of excessive estrogens in the environment. Due to industrial pollution and widespread use of oral contraceptives, there are high levels of estrogens found in water in many places. In some rivers, fish are dying out because there’s so much estrogen in the water that all the fish are born female. In this scenario, average breast size is growing due to this hormonal pollution.

      1. I worked with a guy who was a biostatistician and basically advocated hormonal mitigation of invasive fish species. There was a way to push them to by YY after they were born. Basically forcing all of them to be born male.

  16. Since WWII, the use of syphilis drugs alone should have sky-rocketed male fertility rates.

  17. I find it telling that SOCIETY classifies testosterone as a controlled substance and estrogen as an environmental pollutant.

    1. What does this have to do with abortion?

  18. If there is ever a Sperm Apocalypse, I am sure that Warty will have something to do with it.

  19. The judges would have also accepted Bukkake Holocaust and Spunk Eschaton.

    1. Oh my god man….do you know what you’ve just done to the nested thread?!

      1. ….apparently not much.

  20. There are actually a few endocrine disrupting plants out there you still should keep away from. Liquorice has been shown in studies to cut testosterone by something like half. Peppermint/spearmint isn’t too good for it either. Lavender should probably be avoided by young boys who can be affected by small amounts of estrogen as there are some reports of breast growth and in vitro studies showing it contains chemicals which can bind to estrogen receptors. Finally, our good old friend hops – female workers in the field reportedly experienced early periods due to the estrogenic substances absorbed from the plants.

    1. Lavender should probably be avoided by young boys who can be affected by small amounts of estrogen as there are some reports of breast growth and in vitro studies showing it contains chemicals which can bind to estrogen receptors.

      Lavender should be avoided by young boys on general principle!

    2. Yes. I’ve read of a case where boys developed feminine qualities like growing breasts after exposure to lavender.

    3. Check the direction of your causation arrow. I think spending time around lavendar may not precede a lack of masculine characteristics.

    4. So, uh, what herbs make you more virile? My friend wanted to know.

  21. Estrogen mimics occur in nature. They are called phytoestrogens, and plants make them. Soy is a major source of phytoestrogens.

    1. So tofu is an anti-manliness conspiracy?

  22. I read a convincing analysis in graduate school that said the apparent decline in sperm count really measures a geographical trend, not a temporal one. The early studies were done in New York City, and New York City men have above average sperm counts.

  23. Surprised there’s no mention of the fact that Al Gore wrote the intro to “Our Stolen Future.”

    1. Oh, well, then the science is settled.

  24. Most people don’t seem to have any trouble making babies. I’m not too worried.

  25. This cant be! Arent people like Colburn all part of the “reality based community”?

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