The rapid decline in male fertility does not only concern the countries of the North, but the whole world. Far from slowing down to stabilize, the phenomenon is rapidly accelerating. These are the salient elements of the summary work, published on Tuesday, November 15 in the journal Human Reproduction Updatethe most exhaustive conducted to date on the fall in the concentration of spermatozoa in humans.
The causes of this decline have been the subject of much research for the past twenty years, pointing to individual factors related to lifestyle (smoking, sedentary lifestyle, diet, etc.) and environmental causes related to air pollution, various drugs and the omnipresence of certain synthetic substances in the environment and the food chain (plasticizers and pesticides in particular).
Epidemiologists Hagai Levine (Hebrew University of Jerusalem), Shanna Swan (Mount-Sinai School of Medicine in New York), and their colleagues have brought together the results of all the studies published – several hundred – on the subject. They identified data available in more than fifty countries, covering the period 1973-2018 in total.
From 1973 to 2018, the average concentration of gametes in semen increased from 101 to 49 million per milliliter
According to their results, during these forty-six years, the average concentration of gametes in the sperm of the general male population fell from 101 million per milliliter (M/ml) to 49 M/ml. A level already considered as that of a “subfertile” man, underlines Mme Swan. “France is no exception.says Hagai Levine. In France, thanks to the availability of good quality data, we are certain that there is a strong and lasting decline, as elsewhere in the world. »
A threat “to the survival of humanity”
Including all data after 1973, the average rate of decline is 1.16% per year worldwide. This rate has more than doubled since the start of the 21ste century, falling to a decline of 2.64% per year over the period 2000-2018. An acceleration qualified as“alarming” by the authors. “Our results are like the canary in the minesays Mr. Levine. We have a serious problem on our hands which, if left unchecked, could threaten the survival of mankind. » Nothing less.
“In this meta-analysis, the largest ever on sperm quality, Hagai Levine and colleagues show a continued decline in sperm countconfirms toxicologist Andreas Kortenkamp (Brunel University, London), who did not participate in this study. The strength of this work is to show for the first time that these trends also concern the countries of Africa and South America. It’s really worrying. »
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