French men’s bedroom reputation has been quite shaken by the results of one of the largest sperm quality study. The research has revealed that, in recent decades, French males’ sperm counts and quality have taken a severe and consistent 32.2 percent nosedive.
Published in the journal Human Reproduction, this nationwide study found that between 1989 and 2005, the average 35-year-old Frenchman’s sperm concentration has been plummeting at a steady rate of 1.9 percent annually — from 73.6 million sperm per millilitre of semen in 1989 to 49.9 million per millilitre in 2005. Abnormally shaped sperm — another factor that adversely affects fertility —were also detected.
Based on the World Health Organization’s criteria, a sperm count above 15 million per millilitre of semen is normal. However, “the 2005 values are lower than the 55 million per ml threshold, below which sperm concentration is expected to influence the time it takes to conceive,” said Joëlle Le Moal, the study’s lead author. And according to Grace Centola, president of the Society for Male Reproduction and Urology in Birmingham, Alabama, “if there continues to be a decrease, we would expect that we’ll get into that infertile range.”
This is far from being a “French-only” phenomenon: the researchers uncovered similar reports of declining sperm counts in studies carried out in India, Israel, New Zealand and Tunisia and have warned that “this constitutes a serious public health warning” with global implications.
During the 17-year period, the scientists analysed semen samples from France’s 126 main assisted reproductive technology (ART) centres. In order to stave off the risk that the men had fertility issues, the researchers selected 26,609 males whose partners were indisputably infertile — these women either had blocked or missing fallopian tubes.
Possible causes of this dwindling male fertility
Although further research is warranted, existing studies blame environmental pollutants such as pesticides and Bisphenol A (BPA). These pollutants act as endocrine disruptors — they mess with the body’s hormonal equilibrium and can alter cell behaviour and gene expression (the way the body utilises information in genes to synthesise a functional product such as gametes; male sperm and female eggs).
Excess body weight, a sedentary lifestyle, overly restrictive diets or yo-yo dieting, tobacco and marijuana smoking, heavy alcohol consumption and the use of anabolic steroids have also been linked to reduced sperm production.
Impact on future generations
According to Le Moal, epigenetic changes — environmental and lifestyle choices that can influence the genetic code — are yet another cause for concern since changes in the genetic material of one individual would have repercussions on later generations. The researcher explains that “if such exposures and effects occur in successive generations, accumulated outcomes are plausible. So the observed trends could be the result of several generations’ changes.”
Le Moal concluded by saying she hopes that their “public health warning” will prompt health authorities to “reinforce their actions on endocrine disruptors, hopefully at the European level, and to sustain research as well as monitoring systems”.
Rolland et al (2013) Decline in semen concentration and morphology in a sample of 26,609 men close to general population between 1989 and 2005 in France. Hum Reprod. 28(2):462-70.