A looming male fertility crisis
July 25, 2017 7:54 PM   Subscribe

A newly published meta-analysis of 185 studies of 42,935 male-bodied people from 1972-2011 [pdf] found that sperm concentration has fallen by 52.4% in North America, Europe Australia and New Zealand—with no sign of stopping. No significant trends were seen in South America, Asia and Africa, but the authors noted that limitations in the underlying studies made it impossible to rule out a significant trend in those continents as well.
While the current study is not designed to provide direct information on the causes of the observed declines, sperm count has been plausibly associated with multiple environmental and lifestyle influences, both prenatally and in adult life. In particular, endocrine disruption from chemical exposures or maternal smoking during critical windows of male reproductive development may play a role in prenatal life, while lifestyle changes and exposure to pesticides may play a role in adult life.
Further,
Declines in sperm count have implications beyond fertility and reproduction. The decline we report here is consistent with reported trends in other male reproductive health indicators, such as testicular germ cell tumors, cryptorchidism, onset of male puberty and total testosterone levels. The public health implications are even wider. Recent studies have shown that poor sperm count is associated with overall morbidity and mortality...Thus, a decline in sperm count might be considered as a ‘canary in the coal mine’ for male health across the lifespan. Our report of a continuing and robust decline should, therefore, trigger research into its causes, aiming for prevention.
posted by jedicus (66 comments total) 17 users marked this as a favorite
 
With no more than trivial training in statistics, I am still amazed at a change of 52% of anything at all in 42,000 of anything at all.
Strikes me as consequential.
posted by Alter Cocker at 8:11 PM on July 25, 2017 [3 favorites]


Children of Men, yo.
posted by leotrotsky at 8:11 PM on July 25, 2017 [26 favorites]


Ironically the paper is a meta-analysis of 185 prior studies, and consists of almost nothing but a detailed description of their statistical methodology
posted by theodolite at 8:12 PM on July 25, 2017 [4 favorites]


"average white man's sperm count decreasing" actualy just statistical error. average white man produces 0 sperms per year. sperms georg, who lives in cave and produces over 10, 000 million each day, is an outlier adn should not have been counted
posted by murphy slaw at 8:13 PM on July 25, 2017 [53 favorites]


can't you explain nearly all of it with "we got super fat, the entire west"?

I mean, there was a report on chinese sperm dropping as they, too, get super fat
posted by hleehowon at 8:15 PM on July 25, 2017 [5 favorites]


consistent with reported trends in other male reproductive health indicators, such as testicular germ cell tumors, cryptorchidism, onset of male puberty and total testosterone levels

Do any of those correlate with other stuff, like increased obesity rates?
posted by Sys Rq at 8:16 PM on July 25, 2017 [2 favorites]


I just don't buy the alarm.

Well, you see, every sperm is sacred.
posted by XMLicious at 8:16 PM on July 25, 2017 [27 favorites]


a change in 52% of 42,000 men

No. A 52% change in 42,000 men.
posted by Sys Rq at 8:17 PM on July 25, 2017 [3 favorites]


"Do you realize that in addition to fluoridating water, why, there are studies underway to fluoridate salt, flour, fruit juices, soup, sugar, milk, ice cream? Ice cream, Mandrake? Children's ice cream!...You know when fluoridation began?...1946. 1946, Mandrake. How does that coincide with your post-war Commie conspiracy, huh? It's incredibly obvious, isn't it? A foreign substance is introduced into our precious bodily fluids without the knowledge of the individual, and certainly without any choice. That's the way your hard-core Commie works. I first became aware of it, Mandrake, during the physical act of love...Yes, a profound sense of fatigue, a feeling of emptiness followed. Luckily I-I was able to interpret these feelings correctly. Loss of essence. I can assure you it has not recurred, Mandrake. Women, er, women sense my power, and they seek the life essence. I do not avoid women, Mandrake...but I do deny them my essence."

-General Jack D Ripper in Dr Strangelove
posted by Pantalaimon at 8:19 PM on July 25, 2017 [26 favorites]


It's all the Onanism we practice.
posted by Annika Cicada at 8:21 PM on July 25, 2017 [2 favorites]


on the one hand, a decrease in average human fertility is probably a good thing for the planet.
on the other hand, struggling with fertility issues is a horrible thing for individual couples who want to have kids.
posted by murphy slaw at 8:22 PM on July 25, 2017 [25 favorites]


A meta analysis is only as good as the studies it's analysing. I feel this is unnecessarily alarmist.
posted by Homo neanderthalensis at 8:28 PM on July 25, 2017 [4 favorites]


Feel free to engage with the studies it is analysing then.
posted by the agents of KAOS at 8:31 PM on July 25, 2017 [9 favorites]


So, please let us hear from members with the background in math and statistics currently believed to provide an accurate analysis of data regarding such trends.

Please do explain your training and background... I am so tired of hearing opinions offered on matters susceptible to statistical analysis with no basis beyond it's SHINY!!!/synced with my prior attitude towards an internet or MSM article pop sci conclusion...

Sorry. Old and bitter.

About 50 years ago, my father expressed to me his thoughts on organisms that live in their own waste products and their survival. He was a research scientist with a PhD in high energy physics, the impetus for his remarks was a combination of news about the three mile island meltdown coupled with his knowledge of studies on radionuclide prevalence in the biosphere post WWII. And his own cynicism regarding the failability of human institutions.
posted by bert2368 at 8:32 PM on July 25, 2017 [5 favorites]


The salmon caught in the Seattle area are full of drugs. Girls have been arriving at puberty years earlier than normal for some time. As a teacher I watched eight year old girls with seeming PMS. The estrogen imitating substances in all kinds of products we put on our skin, are enough to change men too. They are enough to make little boys have man guts. Only when things effect men then will change come. We have gone on and on about the chemicals used in agriculture, beauty culture, only when something happens to men then there is a crisis. The blue pill is indicative of more than one crisis. Maybe its existence has hidden this reality for some time.
posted by Oyéah at 8:37 PM on July 25, 2017 [18 favorites]


The people who want to wait until the damage is already done to question whether the amount of chemical dump in our products and food and environment is a good idea are already standing against basic common sense and they have dominated this argument since the beginning because the people with power and business/money interests make anyone who questions them into a laughing stock.
posted by xarnop at 8:49 PM on July 25, 2017 [4 favorites]


I will only drink rain water and pure grain alcohol from now on.
posted by vorpal bunny at 8:52 PM on July 25, 2017 [22 favorites]


Kids can't concentrate in school, I can't concentrate on the bus, sperm can't concentrate in our balls - welcome to the busy, doggy-dog world of the 21st century.
posted by turbid dahlia at 8:56 PM on July 25, 2017 [4 favorites]


Life... finds a way to rid the planet of humans.
posted by runcifex at 9:13 PM on July 25, 2017 [10 favorites]


This isn't scary data right after I finished the Handmaids Tale at all!
posted by corb at 9:18 PM on July 25, 2017 [17 favorites]


Life... finds a way to rid the planet of humans.

See also: the Medea hypothesis
posted by dephlogisticated at 9:20 PM on July 25, 2017 [1 favorite]


Soda pop is definitely also sufficient to give little boys man guts
posted by hleehowon at 9:28 PM on July 25, 2017 [12 favorites]


The secret plans of The Feminist Cabal are working! The glorious matriarchy cometh!
posted by schroedinger at 9:34 PM on July 25, 2017 [7 favorites]


This would be pretty scary if we weren't about to CRISPR everything anyhow
posted by East Manitoba Regional Junior Kabaddi Champion '94 at 9:46 PM on July 25, 2017 [1 favorite]


Salt intake is a recent concern in those countries. Mostly hidden in snacks and fast foods, it is highest in men and linked to other disorders. And there's this, showing that white leghorn cocks fed higher concentrations of saline water had negative effects on their sperm.
posted by Brian B. at 10:15 PM on July 25, 2017 [3 favorites]


can't you explain nearly all of it with "we got super fat, the entire west"?

You could explain it with the aliens on the moon who are shooting kappa rays at our scrotums, but it would still be speculation like the rest of this thread.
posted by dilaudid at 10:16 PM on July 25, 2017 [48 favorites]


Are you saying its the Salarian genophage kicking in, dilaudid? Because that would explain some stuff.
posted by Justinian at 10:21 PM on July 25, 2017 [7 favorites]


They mention smoking, but I have to doubt the cause is smoking if Asia is unaffected.
posted by fshgrl at 10:26 PM on July 25, 2017 [2 favorites]


They mention smoking, but I have to doubt the cause is smoking if Asia is unaffected.

As global textile manufacturing was concentrated in Asia, a sinister plot was hatched by the fashion industry to decrease the size of the men's underwear and trousers shipped everywhere else bit by bit. We're like frogs who have had their gonads pinched off slowly and gradually rather than quickly.

† Pinched frog gonads are also a French delicacy.
posted by XMLicious at 11:51 PM on July 25, 2017 [2 favorites]


My roommate who believes in all the conspiracy theories says it's from the emasculating chemicals in CHEMTRAILS.
posted by a humble nudibranch at 11:59 PM on July 25, 2017


With the ever-increasing and largely unregulated flow of estrogen-mimicking chemicals into our bodies, government and industry are conspiring to reduce the number of sperm in men's balls so there's more room in there for RFID chips and godknowswhatelse!
posted by tenderly at 12:12 AM on July 26, 2017 [1 favorite]


If maintaining the population means I have to have sex twice or even three times more often then so help me I will make that sacrifice*.

* it would still be zero :(
posted by um at 12:20 AM on July 26, 2017 [6 favorites]


Rising rates of obesity and obesity's cascading effects on hormones would seem to be the most logical explanation.

If you think that somehow declining fertility is a solution for the problems the planet faces, you should also know that population growth is actually slowing down anyway due to rising incomes--increasing globalization and trade is doing more to solve the population crisis than eugenics (i.e., sterility) ever will.

And as the article said, declining sperm counts leave men more at risk for serious diseases such as cancer. No matter what you think, I'm sure we can all agree that cancer is bad and we shouldn't wish it on anyone.
posted by My Dad at 1:30 AM on July 26, 2017 [6 favorites]


So sperm went from approximately 99 million/ml to 47 million/ml. I just googled it and a low sperm count is under 15 million/ml. At the rate of a 1.5% decline a year (from the article), it would take another 75 years to reach the low sperm count threshold.

Anyway, I don't think we need to be suddenly panicking that we are about to enter a Cormac McCarthy novel here. I also don't think that this will encourage much more introspection about men's reproductive health, at least not any time soon. I mean it isn't like the average man is at a low fertility level (yet), and historically it seems like fertility problems were always blamed on women anyway, so I am not hopeful.

Still this is really interesting, and I wonder if the cause will be as simple as obesity, or maybe all the BPA plastic and synthetic estrogen, or something much more frightening and irreversible. As an uneducated rube, my money is on it being caused by obesity, sedentary lifestyles, poor diet and low grade poisons from a variety of sources.

Great post, anyway.
posted by Literaryhero at 2:04 AM on July 26, 2017 [5 favorites]


An evolutionary response to near-universal use of contraception? The number of offspring you have no longer depends very much on your fertility, so you don't need it to be as high, or to put it more correctly, low fertility men have just as many offspring as high fertility ones and so are not constantly whittled down as a percentage of the population in succeeding generations.
posted by Segundus at 3:45 AM on July 26, 2017 [6 favorites]


welcome to the busy, doggy-dog world of the 21st century.

OMG - - even the accuracy of our idioms has fallen by 52%!
posted by fairmettle at 3:53 AM on July 26, 2017 [37 favorites]


Segundus, it would make for an interesting study (although I'm not sure how it could get through the sieve of ethics committees) to quantify how many more children are being born in how many generations due to improved healthcare and living conditions, compared to a long-term previous average.

I have a feeling, that in the Western world it's only been about 4-5 generations (since about the 1920's when infant mortality and birthrates began falling.

If your hypothesis is right, then that would point to a huge genetic variability from generation to generation in sperm counts.
posted by Laotic at 4:30 AM on July 26, 2017 [2 favorites]


My roommate who believes in all the conspiracy theories says it's from the emasculating chemicals in CHEMTRAILS.

Actually it's mostly from Ghostbusters (2016).
posted by uncleozzy at 4:31 AM on July 26, 2017 [5 favorites]


I want to hear more about these kappa rays.
posted by NoMich at 4:53 AM on July 26, 2017


Also, by "male-bodied people", I think you mean cis men. Trans men are "male-bodied" as well, and are not included in these studies, presumably. Trans women are not "male-bodied", and it likewise wouldn't make sense for them to be included in these studies, since transition affects fertility (in ways that are poorly understood and that I hope will be better researched eventually, but that's neither here nor there!)
posted by ITheCosmos at 5:06 AM on July 26, 2017 [12 favorites]


OMG - - even the accuracy of our idioms has fallen by 52%!

In the context of an article on fertility? 100% accurate.
posted by 1adam12 at 5:22 AM on July 26, 2017


I just think it's nice to hear some encouraging news for a change.
posted by Faint of Butt at 5:40 AM on July 26, 2017 [3 favorites]


I'll see your male fertility crisis and raise you a world population crisis:

Future generations will face a growing population crisis stemming from the ironic fact that we will have both too many people and too few: too many fighting for finite resources and too few to sustain aging populations across the globe.

We are a blight on the planet. There are too many of us.
posted by bunderful at 5:40 AM on July 26, 2017 [4 favorites]


One way or another, humans will outpace themselves. We have less than 1,000 years left, and that is a generous estimate.
posted by agregoli at 5:41 AM on July 26, 2017 [2 favorites]


This brings to mind the obesogen hypothesis (first proposed in this paper in the peer-reviewed literature; previously): persistent hormonally active environmental pollutants may be linked to the obesity epidemic. This paper claims that even lab animals show increasing weight over time. Perhaps environmental pollutants can explain both the obesity epidemic and reduced sperm counts?
posted by A Mind of Winter at 6:06 AM on July 26, 2017 [8 favorites]


> Only once the global imperialists are wiped out will the space Trotskyists reveal themselves to us and help us to live in harmony with the dolphins.

I've heard worse plans.
posted by The Card Cheat at 6:21 AM on July 26, 2017 [1 favorite]


It's all the weed. Ruining our national productivity too.
posted by Morpeth at 6:28 AM on July 26, 2017


[A few deleted. Let's skip the Kill All Humans derail, thanks.]
posted by taz (staff) at 6:38 AM on July 26, 2017 [8 favorites]


I think a change so severe in so short a time points more toward some kind of measurement error over the years. Maybe measurement is more accurate now?
posted by FakeFreyja at 6:42 AM on July 26, 2017


Purity Of Essence


Peace
On
Earth
posted by indubitable at 6:45 AM on July 26, 2017 [1 favorite]


*adds a tin foil codpiece to my hat and gloves*
posted by Bee'sWing at 7:10 AM on July 26, 2017 [6 favorites]


Very good point, A Mind Of Winter. A few papers have suggested that the obesity epidemic may be caused by air pollution, specifically CO2 working in concert with PM2.5.
posted by MrVisible at 7:35 AM on July 26, 2017


Maybe this is the reason?
posted by Catblack at 8:30 AM on July 26, 2017


Are there victims? Let's blame them.

Here is some info from a fertility site.
posted by Oyéah at 8:33 AM on July 26, 2017 [1 favorite]


immigration is a reliable way to manipulate obesity: up, in the case of immigrants to the US. if it were a true obesogen, i suspect that it wouldn't be manipulable from one industrialized country to another. but korean-americans get fat like everyone else, and so do european-americans. see this. japanese-brazilians who moved back to japan get thinner, which would be weird if it were an obesogen because japan does sophisticated chemical manufacturing and shit

i suspect highly that the more important thing is shit you see on the tv and the supermarkets and the normative portion sizes and the method in which people get treated like shit in each culture
posted by hleehowon at 8:42 AM on July 26, 2017 [3 favorites]


Be nice if there was a corresponding drop in the birth rate.
posted by terrapin at 8:50 AM on July 26, 2017 [2 favorites]


A meta analysis is only as good as the studies it's analysing. I feel this is unnecessarily alarmist.

Folks you gotta read the freaking paper!

First, it's worth point out that systematic reviews/meta-analyses (which are distinct, and this study is a combination of the two) are the highest form of empirical evidence we have when it comes to health-related studies. It doesn't get any more statistically sound. And this study is a super well-done example of that method. They followed every established protocol for doing this type of study, and had eight reviewers, which is like 4x as many as you often see. Furthermore, they go to great lengths to lay out their exclusion criteria, which is quite strict (e.g. fewer than 10 subjects, other factors affecting fertility, unconventional collection methods, etc).

Their selection methodology was, I think, as good as you could possibly expect. And even with strict methods, they still managed to get a huge body of papers for a meta-analysis. 185 studies is a pretty impressive and their statistical methodology was rigorous and transparent. I was impressed, personally.

I think a change so severe in so short a time points more toward some kind of measurement error over the years.

Again, this is addressed in the study. They used sperm concentration and total sperm count - both of which were found to have statistically significant and practically significant drops across the studies. They excluded newer methods (e.g. morphology) since there was just not enough studies which use some of these newer techniques.

consistent with reported trends in other male reproductive health indicators, such as testicular germ cell tumors, cryptorchidism, onset of male puberty and total testosterone levels

Do any of those correlate with other stuff, like increased obesity rates?


Again, from the study, perhaps not directly, but both are at least associated with low sperm count. So I think it's plausible there are links.

The har har overpopulation stuff is fine but 50% decrease in sperm count is enormous and very troubling, since sperm count predicts all-cause mortality morbidity. And it's not just about the menz - certainly, as this study posits, if this dramatic reduction in sperm count is a sensitive measure of the impact of the modern environment on health, we should all be alarmed for everyone.
posted by Lutoslawski at 9:05 AM on July 26, 2017 [30 favorites]


unconventional collection methods

I... I have questions...
posted by Hairy Lobster at 2:47 PM on July 26, 2017 [2 favorites]


Color me disappointed that the regression curve had no jokey analogue to the current era of peak porn.

historically it seems like fertility problems were always blamed on women anyway, so I am not hopeful

"Yeah..um...that's changed" says a member of the Discrete Brown Bag at the Lab club. Procreate early everybody! Oh the tests you'll save.
posted by Ogre Lawless at 3:41 PM on July 26, 2017 [1 favorite]


Obesity is apparently such an a unadulterated evil that even so much as a gesture toward a possible mechanism whereby obesity could cause low sperm counts is evidently superfluous.

But in fact, fat cells are very important sources of hormones:
It is now widely accepted that white adipose tissue (WAT) secretes a number of peptide hormones, including leptin, several cytokines, adipsin and acylation-stimulating protein (ASP), angiotensinogen, plasminogen activator inhibitor-1 (PAI-1), adiponectin, resistin etc., and also produces steroids hormones. This newly discovered secretory function has shifted our view of WAT, which is no longer considered only an energy storage tissue but a major endocrine organ, at the heart of a complex network influencing energy homeostasis, glucose and lipid metabolism, vascular homeostasis, immune response and even reproduction.
and far from causing low sperm counts, obesity appears to be a response to disruption of endocrine hormone systems by industrial chemicals, in which adipose tissue supplies hormones which are not available in sufficient quantity from the disrupted endocrine system.

And I think that's why little boys are getting "man guts", because when the body tries to rev up the endocrine system for puberty, the engine sputters and extra hormones from fat become necessary -- which is exactly the same reason men tend to get pot bellies when their male hormones begin to decline.
posted by jamjam at 3:41 PM on July 26, 2017 [1 favorite]


jamjam, the hormonal effects of fat tissue are a concern exactly because it acts as an endocrine organ. We know fat is essential to life, and the hormones it produces is one of the reasons. But the fact that it is essential doesn't mean it's healthy for the system no matter the amount. The endocrine system is pretty complex and we know that excess amounts of any hormone can seriously throw things out of whack in areas where you wouldn't expect.

Anyway, scientists have looked at the connection between obesity and fertility, and there are plenty of individual studies as well as reviews of the research on the subject. The results are pretty unanimous that the effects are not good.
posted by schroedinger at 4:13 PM on July 26, 2017 [2 favorites]


"You could explain it with the aliens on the moon who are shooting kappa rays at our scrotums, but it would still be speculation like the rest of this thread."
That's why I always wear my tinfoil scrotum sleeve, yes it chafes something crazy, but they deflect alien nut sack kappa rays perfectly.
posted by Merlin The Happy Pig at 5:40 PM on July 26, 2017


(A note: all the studies I linked focus on obesity-related fertility issues in men, but it causes fertility issues in women as well)
posted by schroedinger at 9:24 PM on July 26, 2017


Be nice if there was a corresponding drop in the birth rate.

US Birthrste hits historic lows
US Birthrate Falls to Lowest Rate on Record
World fertility rate, total births per women

Granted, it took me like, 10 seconds to Google that, and a whole two minutes to grab the links. I suppose one can be forgiven for not wanting to exert the huge amount of effort needed to do research before posting.
posted by happyroach at 9:57 AM on July 27, 2017 [3 favorites]


Birth control seems to me to make the birth rate largely irrelevant in this context. There has been a ton of stuff going on in the US and even in more "enlightened" countries re: things like maternal leave for several decades now that make larger families or even having children at all a thing that today's adults have to think really, really, really hard about. The underlying issue here seems very worth being concerned about, but there's no reason to think it's having a noticeable impact on the birth rate of today, as far as I can see.
posted by Sequence at 2:13 PM on July 27, 2017


More simply, adipose (fat) tissue is an estrogen producing organ. Excess estrogen causes male gonad dysfunction.

I appreciate that there is often a reflex to blame health issues on obesity and a counterreflex to dispute that, but there is on the face of it biological plausibility to the thesis that obesity is a causative factor in the trend described.
posted by chiquitita at 5:00 PM on July 27, 2017 [1 favorite]


« Older 🚒 🎶 🐕   |   Strange Fruit Newer »


This thread has been archived and is closed to new comments