Withheld Danish Study Shows No Evidence of Sperm Decline

A recent blog posting challenges the notion that some chemicals can cause endocrine effects that reduce human sperm counts.  This posting is an article entitled My Sperm Is Fine—The Myth of Endocrine Disruption. The study it discusses shows no evidence of sperm decline after 16 years of sampling of the most relevant cohort of Danish males. The article suggests that researchers did not publish the study results because they do not support the researchers’ hypothesis of endocrine disruption.

This article explains that

Twenty years ago, a literature review published by Niels Skakkebaek et al concluded that there was a serious decline in male sperm count levels, predicting a doomsday scenario and suggesting that this ‘crisis’ was due to environmental factors (synthetic endocrine disrupting chemicals or EDCs).

 As the scientific evidence was far from certain, from 1996, the Danish government engaged Skakkebaek and his team to conduct a large-scale longitudinal research of young Danish men (around the age of 18 and thus at the peak of their sexual prowess) entering the military from two Danish cities. More than 5000 sperm and blood samples were taken, questionnaires were filled out and data analysed over 16 years. Using the best analytical technology available, the most reliable methodology from the largest sample range ever over an extended time period, the hope was that we could know, once and for all, whether endocrine disruption was occurring, and what was behind this phenomenon. It allowed Skakkebaek to prove his theory which had led to twenty years of robust scientific and regulatory debate.

The scientific community patiently waited for Skakkebaek to release his data – data that would inform the debate and remove doubt once and for all about the state of play regarding our risks from synthetic chemicals (or, more likely, the increased soy in our diet). And they waited some more, but still no data was released. Sixteen years of funding and access provided by the Danish government for scientists to conduct state of the art research and there was only silence. A representative from the Danish National Board of Health, within his right as the research funder, finally demanded access to the data, and upon receiving it, did what any responsible civil servant would do with work funded with public money: he released the data on-line to the public.”

The data when finally released do not support the conclusions in the original Skakkebaek literature review. The data do not support the hypothesis that exposure to certain chemicals causes endocrine effects that reduce sperm counts.  As the article explains:

“It should not come as any surprise that the data from 16 years of comprehensive sampling of the most relevant male cohort showed that there was no evidence of any decline in sperm counts from the thousands of samples taken. Curiously, sperm counts were increasing quite significantly in the last four years before the sampling stopped….”

 The article questions why Government intervention was necessary to release the data to the public, and suggests that the researchers sat on the data because they do not serve the researchers’ political agenda.   The article asks:

“Well, Dr Skakkebaek, is it good scientific practice to withhold data that the public has paid for because it does not support your political views?”

Click here to read article.




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