Trends in global semen parameter values

Fisch, Harry; Braun, Stephen R

doi:10.1038/aja.2012.143

Cited by 29 publications

(17 citation statements)

References 48 publications

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“…Although some recent studies have corroborated this decline in semen quality [31][32][33], others have found no such change [34,35]. The ambiguity on the issue of sperm count decline has been discussed in an interesting review article by Pacey [36].…”

Section: Fertility Decline-loss Of Sperm Function?mentioning

confidence: 90%

Environmental Stressors: Is the Sperm Cell Vulnerable or Resilient?

Highland¹

2016

Andrology(Los Angel)

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The sperm is a unique cell, differing from other cells in physiology and function. It survives an arduous journey through male and female reproductive tracts, to ensure that an intact male genome reaches the site of fertilization. In addition, it has also been recognized to wield epigenetic control over early embryonic development.Environmental degradation over the past years has exposed the human sperm to myriads of toxicants which have adversely affected its structure and function. In correlation, there are reports of decline in sperm counts and fertility, although there is still no concrete evidence to substantiate these claims. Moreover population statistics in most developing nations do not conform to data of declining fertility. In addition there are certain researches, in agreement with our data of normal, fertile volunteers, which also suggest no change in semen characteristics or sperm numbers over the past three decades.These findings indicate that despite the barrage from environmental agents, spermatozoa have withstood the test of time and have emerged resilient. Hence, in addition to the manifold machinery that operate to protect the spermatozoa including toll-like receptors, anti-oxidants, heat shock proteins etc., there possibly exists an in-built, genetically programmed, population specific mechanism that reinforces its nuclear integrity to protect this cell from the onslaught of toxic influences. Research in this direction is underway at our laboratory and other research centers to delve into the enigma of sperm endurance.

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Section: Fertility Decline-loss Of Sperm Function?mentioning

confidence: 90%

Environmental Stressors: Is the Sperm Cell Vulnerable or Resilient?

Highland¹

2016

Andrology(Los Angel)

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“…An evolving body of evidence suggests that decreased semen quality could be related to environmental exposure to oestrogen-like compounds, although some studies have demonstrated conflicting results [144]. Data from randomized human studies show a clear and consistent decline in serum T levels in healthy American men over the years [145], but the trend in the decline in serum T concentration in EDC-exposed men has been more uniform [144].…”

Section: Novel Aspects Of Oestrogen Action In Malesmentioning

confidence: 99%

“…Data from randomized human studies show a clear and consistent decline in serum T levels in healthy American men over the years [145], but the trend in the decline in serum T concentration in EDC-exposed men has been more uniform [144]. Reports have shown lower general sperm counts in Japanese men compared with Caucasian men, which could be associated with the massive consumption of phytoestrogens in Asia, although correlations with other factors, such as genetic diversity or lifestyle issues, cannot be ruled out [146,147].…”

Section: Novel Aspects Of Oestrogen Action In Malesmentioning

confidence: 99%

Oestrogen action and male fertility: experimental and clinical findings

Jia

et al. 2015

Cell. Mol. Life Sci.

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A proper balance between androgen and oestrogen is fundamental for normal male reproductive development and function in both animals and humans. This balance is governed by the cytochrome P450 aromatase, which is expressed also under spatio-temporal control. Oestrogen receptors ERα and/or ERβ, together with the membrane-associated G-protein-coupled functional ER (GPER), mediate the effects of oestrogen in the testis. Oestrogen action in male reproduction is more complex than previously predicted. The androgen/oestrogen balance and its regulation in the masculinisation programming window (MPW) during foetal life is the most critical period for the development of the male reproductive system. If this balance is impaired during the MPW, the male reproductive system may be negatively affected. Recent data from genetically modified mice and human infertile patients have shown that oestrogens may promote the engulfment of live Leydig cells by macrophages leading to male infertility. We also discuss recent data on environmental oestrogen exposure in men and rodents, where a rodent-human distinction is crucial and analyse some aspects of male fertility potentially related to impaired oestrogen/androgen balance.

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“…He also concurs with other authors that such comparisons are unsound because of systematic errors reflecting the fact that methods of laboratory Andrology have changed considerably since the 1950s, with developments in training and competence, emphasis on Quality Assurance and Quality Control, and attempts at standardisation of technique. With Nieschlag and Lerchl, 8 Pastuszak and Lamb 7 and Fisch and Braun, 5 he agrees that the only large prospective study carried out to date, overlooking the problem of uncontrolled sampling, shows no change in sperm concentration over 15 years. He argues that this supports the contention that when laboratory methods are adequately controlled, no secular change in sperm counts are observed.…”

mentioning

confidence: 96%

Falling sperm counts and global oestrogenic pollution: postscript

Cooper¹,

Handelsman²

2013

Asian J Androl

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This Special Issue provides reflections after 20 years, summarized in 12 papers, on the controversial issue of alleged decline in human sperm output due to global oestrogen pollution by industrial chemicals.Virtanen et al. 1 offer no specific critique of the original papers but focus on male reproductive function in their native country because Finnish men allegedly have better sperm production than other Scandinavians. Despite this, from longitudinal studies of semen quality among European populations, they believe that young Finnish men had a declining sperm output between 1998 and 2006. They interpret this as Finland's following a global trend of impaired male reproductive health. As these multicentre studies adopt an uncontrolled population sampling methodology, the lack of evidence that the men included by participating centres truly represent the general male populations from which they were sampled means that inferences, whether relating to either time or place, remain unconvincing.In a thoughtful, articulate contribution, Anawalt 2 concludes that the Carlsen meta-analysis 3 was flawed, its conclusions wrong and the putative explanatory hypothesis therefore lacks foundation. Nevertheless, he argues that these misadventures served as sentinels for potential perils of widespread man-made chemical pollutants, and raised scientific and community awareness of risks to male reproductive health. He considers it likely that some new industrial chemicals ubiquitous in the environment are harmful to male human reproductive health, an area of scientific inquiry that was largely ignored before these articles appeared. In channelling Rachel Carson, however, he overlooks the consequences of her unbalanced pronouncements on the hazards of DDT. While DDT may have harmed certain wildlife (though this is disputed), there is no evidence that DDT ever harmed any humans. Indeed, the elimination of DDT from public health use for malaria prophylaxis had disastrous health and medical impacts involving the resurgence of malaria, causing millions of excess deaths and contributing to drug resistance, a public health disaster detailed elsewhere. 4 These salient unintended consequences of well-meaning but tunnel-visioned activism are less well known than deserved. Anawalt's sneaking admiration for what may seem harmless 'crying wolf' raises the question whether we can expect to make progress through sound science by accepting uncritically false alarms, however implausible, if they make flamboyant enough claims that attract public clamour. The endless opportunities for activists or crusading journalists to employ the hollow echo chamber of the internet for propagation of 'scares' among the general population are hardly a responsible voice of science. Can we justify shouting 'fire' in a crowded theatre on the grounds that it serves as an impromptu fire drill?Fisch and Braun 5 concur with Anawalt 2 that allegations of a worldwide decline in sperm output do not withstand scientific scrutiny. Summarising post-Carlsen studies, they find th...

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Trends in global semen parameter values

Cited by 29 publications

References 48 publications

Environmental Stressors: Is the Sperm Cell Vulnerable or Resilient?

Environmental Stressors: Is the Sperm Cell Vulnerable or Resilient?

Oestrogen action and male fertility: experimental and clinical findings

Falling sperm counts and global oestrogenic pollution: postscript

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