03.01.14 5:00 AM ET
France’s Worst Nightmare Comes True: Declining Sperm Quality
It’s long been a stereotype that French men are naturally gifted lovers, but the cliché—like the country’s male population—may be losing its potency.
The same researchers behind an alarming 2012 study on the decline of the average Frenchman’s sperm have now focused their attention on the geographic regions where swimmer concentration is particularly low—and found pesticides may be at the root of the problem.
Published in the journal Human Reproduction, the landmark 2012 study showed an alarming 30 percent decrease in sperm counts across the country between 1989 and 2005. Researchers looked at 26,600 sperm samples from otherwise virile 35-year-old men whose partners’ fallopian tubes were either blocked or missing—allowing for a more reliable male control group than similar studies analyzing men with prior fertility issues—and found a 1.9 percent annual dip in sperm concentration. Dr. Joëlle Le Moal, the study’s lead author, said the results should precipitate a “serious public health warning” and were likely linked to environmental rather than genetic factors. The study prompted a spate of alarmist headlines: “Decline in French sperm count should be considered global warning”; “Scientists warn of sperm count crisis”; “French men have lost one-third of their sperm.”
And now the refined study offers further proof of the environment’s role in sperm deterioration, says Le Moal, who told Le Monde that she examined the same samples “and compared the trends to those in 21 regions of metropolitan France.” The study showed the steepest declines in sperm counts centered around the country’s rural farming regions of Aquitaine, Midi-Pyrénées and Burgundy.
Le Moal speculates causation between this precipitous drop in sperm concentration and the everyday use of pesticides by men employed in the agricultural sector. According to Le Moal, when controlled for factors like weight, tobacco and alcohol consumption, the logical culprit for the rapid decrease in sperm counts must be correlated with pesticides, which are used in far higher concentration in the affected regions.
But Le Moal’s 2012 study on declining sperm counts—on which this latest study relies—was met with criticism from some scientists. Jens Peter Bonde, a professor of occupational medicine at Copenhagen University, told the Guardian that the study should be treated skeptically, considering it found highe average sperm counts than in previous studies of French men. "Sperm counting is difficult. This conflicting data illustrates the problems with comparing sperm counting across centres without strict control of counting methods.”
Still, Le Moal sees sperm monitoring as a rosetta stone for monitoring public health. “It is very important to monitor the quality of sperm,” she told Le Monde, “because it acts as a sensitive biomarker for environmental exposures and is correlated with life expectancy.”