Egg and sperm race

Q. Are we not men? A. We are Devo!

Over the last few decades, a growing number of scientific papers have documented a widespread and consistent decline in male sperm count and quality.

A recent meta-analysis that pooled data from over 40,000 males from North America, Europe, Australia and New Zealand  (1), reported that sperm counts and sperm concentrations declined by 50 – 60% over the period 1973 to 2011. 

This finding was not the first one of its kind, and evidence that the male gonads are under attack can be traced as far back as the 1940’s. This was shown in a seminal (sorry) meta-analysis published by the University Department of Growth and Reproduction at the Rigshospitalet in Copenhagen (2), which documented a deterioration in sperm counts and ejaculate from 1938 to 1991. These findings were confirmed by an ancillary study, which found parallel changes in men from 1934 to 1996 (3). 

Large meta-analyses such as these can be criticized on the grounds that they do not always take regional differences into account, and may not be measuring like with like. The methodology used to measure sperm number and quality may be different in different countries, for example, and some have suggested that the data are too diffuse to mean very much (4, 5). So there is value, also, in more contained and more localized research. 

A large French investigation (6) reported declining sperm concentrations and quality in a group of 26, 609 men in the period from 1989 to 2005. The authors described it as the first study that had found a severe and general decrease in sperm concentration and morphology at the scale of a whole country over a substantial period, and termed it a  ‘a serious public health warning.’

Other scientists have found similar trends in sub-fertile males, where sperm counts have been found to be falling in Sweden (7), and in the USA (8).

Taken together, these and the majority of the other investigations to date suggest that sperm counts and quality are indeed falling in Western and Westernised countries.

A major weakness of these studies, however, is that they do not include non-Western countries. When the major meta-analyses were collated, there were not enough available non-western data to work with. But that has changed. 

In the last few years, parallel findings have been independently reported in two separate China studies. In one group of 5210 sperm bank donors (9), ejaculate volume and sperm counts, concentrations and motility all fell significantly over the 7 years from 2008 to 2015; while in another group of 36,636 males (10), the same negative trends (plus an increase in damaged sperm) were recorded over the period 2001 to 2015.

On balance, therefore, the problem appears to be a real one, and it is further supported by findings that male testosterone values have been falling for the last three decades (11). It appears that men are becoming less masculine.

Some doctors – bless ‘em! – reckon this might be due to tight-fitting underpants. 

There are plenty of homespun types among the medical ranks, either hoping for simple solutions or congenitally incapable of thinking in terms of multi-variable models. You can see why they might obsess about underwear, because garments that hold the testicles closer to the body raise the temperature of these notoriously temperature-sensitive organs. And to be fair, there is evidence that this may be a part of the problem; one Harvard study (12) found that men who wore boxer shorts had a 25 per cent higher sperm concentration, 17 per cent higher total sperm count and 33 per cent more swimming sperm in a single ejaculate than men who wore other types of underwear.

This was actually quite a good study, because the clinicians adjusted for other factors that might have affected the results such as differences in age, body mass index and smoking; and they found also that serum levels of FSH were raised in the non-boxer short brigade, which they assumed, probably correctly, was an attempt by the body to overcome the result of testicular over-heating.

But can short-term and fickle changes in male fashion really be the explanation for a worldwide and decades long problem?

Let us consider some other possible factors. Spermatogenesis is known to be adversely affected by smoking (13, 14), obesity (15), and possibly by diabetes (16), exposure to inhaled particulates (17) and xeno-estrogens (8). Smoking is a common issue, and is increasing in the non-Western world due to the criminal activities of Big Tobacco. Obesity is increasing generally, as is diabetes; and in many areas, exposure to inhaled particulates and endocrine disruptors such as the phthalates and some biocides may also be increasing. So all of these factors are probably in play, to a variable extent. And most of them are mediated, at least in part, by inflammation.

Spermatogenesis is regulated by a balance of many pro- and anti-inflammatory mediators, and an excessively pro-inflammatory environment disrupts the process (18). Smoking, obesity, diabetes and exposure to particulates are all pro-inflammatory. 

Testosterone is a complication here, as it is in many other areas of life. The male hormone has anti-inflammatory properties (ie 19), but if the environment in the body in general and the testicles in particular is sufficiently pro-inflammatory to inhibit sperm formation, testosterone synthesis in the Leydig cells is likely to be adversely affected too (20). If testosterone synthesis is reduced, which is what appears to be happening (11), then the removal of its anti-inflammatory effects in the testes would make the local environment even more pro-inflammatory, thus inhibiting sperm formation in at least two major ways.

Some activists suggest that excessive consumption of soy products has had an adverse effect on masculinity, and there is probably some truth in this. It appears that the combination of soy products and the biocide glyphosate is especially toxic to sperm formation (21); and as most soy is grown with Roundup (glyphosate), and as many soy products contain traces of glyphosate (22), this looks as if it may be a real concern. Combined with an ultra-processed, obesogenic and pro-inflammatory diet, this would be enough to explain falls in both sperm counts and testosterone.

An excessively inflammatory environment in the body increases the risk of benign prostatic hyperplasia (23) and contributes to the increasing incidence of testicular and prostate cancer (24) – so men do seem to be under threat.

Female infertility is growing too, and for some of the same reasons, but there are socio-political factors too. Birth rates fall as women become more educated and gain better access to birth control. As fewer babies are born, the average age of the population increases; and bellwether populations such as the Japanese are shrinking and ageing simultaneously. The impact on pension plans is considerable, which is one of the reasons why our corrupt and foolish politicians have been complicit in illegal mass migration into Europe and North America. They ignore the fact that AI and robotics are reducing employment opportunities year on year, especially for the unskilled; that the historical factors that originally grew and sustained the middle class no longer exist; and that the macroeconomic indicators all show an imminent downturn.

The twin elephant in the room is, of course, the problem of African fertility, and the alarming fact that the Sub-Saharan population is growing at an annual rate of 2.5%. Another example of the limitations of linear Western thinking, it is the result of decades of well-intentioned programs set up to reduce infant mortality in the Dark Continent. The do-gooders failed to co-promote family planning, good governance, basic economic theory or indeed any of the many elements needed to underpin a so-called ‘advanced’ economy, resulting in population growth so rapid that it has bought urban infrastructures to breaking point, and created insurmountable environmental and food management problems.

Tomorrow’s world will be mostly African and Asian, a prospect which I, as an ageing Caucasian, view with mixed feelings. I am aware of the predominantly Caucasian contribution to 19^th and 20^th century art and science, but Asian involvement was greater in the period right up to the 18^th century, and will be again. And science is universal, although local flavors may vary.

The OBOR projects will shape and change our world unless the neocon crazies in Washington and Tel Aviv exercise the Samson option.

References:

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2. Carlsen E, Giwercman A, Keiding N, Skakkebaek NE. Evidence for decreasing quality of semen during past 50 years. BMJ. 1992 Sep 12;305(6854):609-13.
3. Swan SH, Elkin EP, Fenster L. The question of declining sperm density revisited: an analysis of 101 studies published 1934-1996. Environ Health Perspect. 2000 Oct;108(10):961-6
4. Ravanos K, Petousis S, Margioula-Siarkou C, Papatheodorou A, Panagiotidis Y, Prapas N, Prapas Y. Declining Sperm Counts… or Rather Not? A Mini Review. Obstet Gynecol Surv. 2018 Oct;73(10):595-605. 
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7. Bendvold E, Gottlieb C, Bygdeman M, Eneroth P. Depressed semen quality in Swedish men from barren couples: a study over three decades. Arch Androl. 1991 May-Jun;26(3):189-94.
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