MOSCOW, Nov. 24, Nikolai Guryanov. Male fertility is declining around the world. And on such a scale that it causes great concern among scientists. What is happening and whether it is possible to correct the situation — in the article .
«Canary in a coal mine»
This has been noticed for a long time. So far, however, studies have only been carried out in developed countries. Now it turned out that the process is global. An international team of scientists led by Professor Hagay Levin from the Hebrew University of Jerusalem has revealed a decrease in the concentration of sperm in men on all continents. th to 2000, the indicator decreased by an average of 1.16% per year, now it is by 2.64%.
ДThe WHO threshold of 15 million/ml is still far away, but anecdotal studies show that it is problematic to conceive a child even at 40 million/ml. At current rates, this level will be the world average in a decade, Levine said.
«Our results are a canary in a coal mine,» he says. «The problem is serious. If it is not mitigated, it could become a threat to humanity.»< br />
Oleg Apolikhin, chief freelance reproductive health specialist of the Ministry of Health, director of the Lopatkin Research Institute of Urology, notes that ejaculate worsens in all age categories, but especially in men from 18 to 30 years old.
And male infertility occurs more and more frequently. According to Rosstat, the number of Russian men unable to conceive has doubled since 2000. According to WHO, if in the 1970s there were five percent of infertile couples in the world, now it is 15-25.
“Half a century ago, infertility in a couple, as a rule, was associated with a woman’s reproductive performance. Now it’s about half,” says Alexander Lapshikhin, obstetrician-gynecologist, reproductologist, head of the ART department at the REMEDI Institute of Reproductive Medicine.
It is not known whether it affects deteriorating sperm quality in demographics, but according to some experts, problems with male fertility have contributed to declining birth rates in countries such as the US and China.
«Of course, there are other factors. In developed countries, no more than two children per family have been born for a long time, in contrast to developing countries, where there are often more than three,» Lapshikhin clarifies.
only people, but also dogs
The decrease in male fertility is explained by obesity, a sedentary lifestyle, and smoking. Overheating is also dangerous — when working with a laptop, frequent trips to the bath, from hot baths. It is possible that the negative impact of the coronavirus — SARS-CoV-2.
«Population crowding in large cities, refusal of physical activity, chronic stress, the prevalence of bad habits — all this weakens fertility,» Lapshikhin emphasizes.
There are a lot of infections in the world,” adds urologist and reproductologist Yevgeny Grekov.
In addition, children are born all later, and over the years, mutations accumulate in spermatozoa. According to experts from the Center for Reproductive and Genetic Health in London, the partners of older future fathers have a higher risk of miscarriage: men over 50 are 33% less likely to have a baby than those under 35.
It is also important exposure to chemicals that hit the endocrine system as a whole. One of the prime suspects is bisphenol A, a key plastic used in thousands of products, from water bottles to dental fillings. Accumulating in tissues, bisphenol A can lead to reproductive pathologies.
The quality of sperm is also deteriorating in animals. For example, in dogs. And at about the same pace: from 1998 to 2014, sperm motility in males fell by 30%. At the same time, phthalates were found in biomaterial taken from tetrapods, which are still widely used in various products, from toys to cosmetics, as well as PCBs — polychlorinated biphenyls that have accumulated in the environment (they were banned several decades ago). A three-year-old study shows that these chemicals have similar effects on sperm in both dogs and humans.
Another issue is air pollution. We are talking about the so-called PM-2.5 particles (solid and liquid, ranging in size from ten nanometers to 2.5 micrometers). A 2017 study found an association between the quality of Taiwanese sperm and the concentration of these particles in the environment. An increase of five micrograms per cubic meter of air worsened the proportion of normal and abnormal spermatozoa by more than a percent.
«We urge a global effort to improve the environment and stop behaviors that threaten our reproductive health,» Levin said.
Some, however, believe that the environmental threat to men's health is greatly exaggerated.
“We have eight billion people on the planet, and the last two billion have been added in twenty years,” Grekov argues. “Can we say that the human species is dying out? We don’t know how to slow down population growth. our fertility is so bad.»
Men can't — robots will help
Modern technologies come to the aid of men who are unable to conceive a child naturally. According to WHO data for 2020, more than five million children in the world were born thanks to assisted reproductive technologies (ART). There are a number of medical methods, including surgical removal of sperm.
Futuristic technologies are also being developed. So, in 2016, German scientists created nanobots that help sperm find their way to the egg. «Spermobot», which is a spiral of iron and titanium 50 microns long and five to eight microns in diameter, wraps around the tail of the male germ cell, increasing its mobility. Power supply — from the magnetic field. In the future, such developments may become a cheaper alternative to artificial insemination and IVF.
When it comes to fertility prevention, doctors recommend loose underwear that is 25% less damaging to sperm than tight underwear. Scientists from the United States made such a conclusion by observing 501 men trying to conceive a child during the year. eat, exercise, go to bed on time. But in order to really turn the tide, you need to change your behavior, habits, Oleg Apolikhin is sure.
«We have two sources of the need for food — the limbic system and the cortical one. The cortical one is connected with the body's real need for food, the limbic one turns on when a person eats, because the product smells delicious and looks good. He no longer wants, but continues, because such a behavioral pattern has formed,» the expert says.
Food manufacturers take advantage of this by releasing a product that is more affordable and commercially attractive, but far from useful, including for reproductive ability, product.
«Such an important hormone as growth hormone, which stimulates the production of testosterone, the main driver of male behavior that also affects spermatogenesis, is produced during sleep with 22 hours to one in the morning, and the closer to one, the less it is. And many young people spend their nights on the Internet. If a person goes to bed after 12, he actually robs himself. Biorhythms change, and instead of somatotropin, the stress hormone cortisol is formed, which is already enough,” Apolikhin adds.
Cortisol stress is neutralized by exercise or meditation. But people prefer alcohol and overeating, which turns into internal intoxication.
Impaired fertility is an indicator of the general condition of the body. There are studies showing that in men with low reproductive indices in three or four parameters, life is reduced by about six years, and healthy — by eight.