Western Men's Free-falling Sperm Count Is a 'Titanic Moment for the Human Species'

In the past 40 years, Western men's sperm count has declined by half. What can be done to counter the trend?

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Netta Ahituv
Netta Ahituv
Netta Ahituv
Netta Ahituv

Ten years ago this month, a jury in the United States decided that the international food conglomerate Dole should pay $3.3 million to six farmers in Nicaragua. The reason: use of a pesticide, DBPC, that kills microscopic worms that inhabit the roots of banana trees and that, as a side effect, renders men who work in banana groves sterile. The six farmers, who worked in Dole’s banana plantations and were left irreversibly sterile, maintained that Dole knew about the pesticide’s effects but didn’t warn them. For Dole, the payout was a minor glitch in its profuse cash flow. The company continues to be a highly successful and powerful player in the international food market.

Now it turns out that the tragedy of the plaintiffs is actually the lot of Western men in general. Over the past 40 years, sperm counts of men in Western countries have fallen on average by half. But in contrast to the case of Dole and the Nicaraguan men, where the cause-effect relationship is clear – the more general problem among men in the West is not so easy to decipher. To begin with, not enough research has been done to uncover the exact causes of the extreme decline in sperm counts, and even after the reasons are discovered, reversing the problem will require radical reforms in today’s lifestyle and there is much doubt about whether human kind is ready to change its way of living so drastically. But one thing is clear: Something very dramatic is happening to human beings on the planet, particularly the male species.

“The reproductive system is very sensitive to external factors,” says Dr. Hagai Levine, an epidemiologist and head of Environmental Health Studies at the Hebrew University-Hadassah School of Public Health and Community Medicine. “To be fertile and create new life, a safe, balanced and benign environment is needed, which signals to the body that it’s worth bringing more life into the world. The sperm count decline is an indicator of a disruption that is affecting every one of us, males and females alike.”

Levine led a team that carried out the most comprehensive study ever done on male fertility. The research was undertaken in 2015, during a sabbatical he spent at Mount Sinai School of Medicine in New York; it was supported by the nonprofit, Israel-based Environment and Health Fund.

Levine, together with Prof. Shanna Swan, from Mount Sinai’s Department of Environmental Medicine and Public Health, and an international team of researchers, examined the findings from 7,500 different studies of sperm counts and classified them according to rigorous criteria. For example, they excluded results from studies involving male subjects who stated that they had a fertility problem of any kind, or of men who smoke, as smoking is known to cause a decline in the sperm count. The studies they found appropriate for their project focused on men who were about to be drafted or students, who generally knew nothing about their fertility status (meaning, no men who were trying to find out why they were infertile), and whose sperm count had been measured by an identical method. After screening the 7,500 studies by these criteria, the team was left with 185 studies conducted between 1973 and 2011 on 43,000 men from around the world.

The results stunned even the researchers. Over the course of those 40 years, among Western males, sperm concentration (the number of sperm per milliliter) fell by 52.4 percent, while total sperm count (sperm concentration multiplied by the volume of the sample) by 59.3 percent.

Intensifying crisis

Four decades ago, the average sperm concentration of men in the West stood at 99 million per millileter; in 2011, it was 47 million. At less than 40 million, reproduction is less likely to occur. Levine’s team also discovered that the decline has become steeper in recent years – the crisis is only intensifying.

'If this trend continues, by 2050 the sperm count of Western men will be zero.'

Levine: “If this trend continues, by 2050 the sperm count of Western men will be zero. That’s a speculative statement, not a verified forecast, but the direction is clear.”

No significant sperm count decline was found in men from Asia and Africa, but according to Levine, the reason for this may be that fewer studies of male fertility have been conducted in the countries of those continents, so not enough information is available to determine trends. However, two independent studies showed that recent years have seen a decline in the sperm count in both China and Japan.

The study carried out by Levine and his colleagues is known as a meta-analysis, which he defines as “a statistical analysis of the results of a large number of studies in order to answer certain questions in the best and most comprehensive way.” He adds that his team’s research “did not prove, and did not set out to prove, what accounts for the decline. But it does provide solid evidence of a clear and consistent trend of a decrease in the sperm count in the Western world.”

Was the team surprised by the unequivocal results?

Levine: “I was surprised. I came with an open mind. We carried out dozens of different analyses based on diverse hypotheses, but no matter how we changed the parameters, methodology and variables, the result was the same. It is incomprehensible, unexampled: I don’t know of any other biological index that has fallen so far, so rapidly.”

The first analysis of the decline in sperm count around the world, done in 1992, was carried out by a team of scientists at Copenhagen’s National University Hospital, notes Prof. Swan, the American researcher who collaborated with Levine. “This was followed by a large number of responses (many critical),” she told me in an email exchange. In 1997, Swan published her own analysis, in which she addressed all the negative reactions to the Danish research.

“At first, I was also critical, but my analysis (surprisingly) confirmed the original results,” she relates. “I followed this with a second global analysis..., which also supported these findings. In the 2017 study, we were again surprised how stable the results were in depicting the decline, also in a rigorous analysis.”

Prof. Ronit Haimov-Kochman.Credit: Michal Novoselsky

The results of the Levine-Swan study were published this past July in Human Reproduction Update, considered the leading journal in the field of reproductive biology. In short order, it entered the list of the 100 most quoted articles in the world media and the social networks of this year. The findings confirm the results of an Israeli study conducted over a period of 15 years, ending in 2010, by Prof. Ronit Haimov-Kochman, head of the Department of Women’s Medicine at the Hebrew University of Jerusalem. In her study, Haimov-Kochman examined the sperm count among donors to the hospital’s sperm bank. She found the same trend.

“We have suspected for some time that the environment is the cause of the decline,” Haimov-Kochman says. “The testicles are located external to the body and are therefore strongly affected by the outside temperature. It’s possible that even minor temperature changes, such as those occurring because of global warming, cause a falloff in sperm quality. It might be the non-ionizing radiation from cellphones, or even just the heat that emanates from it in the pants pocket all day. Experiments have shown that [exposure to] plastic products and pesticides also contribute to a decline in the sperm count. The whole Western world should be concerned. And that includes Israel, with its accelerated industry and advanced agriculture.”

Hagai Levine, too, is worried. “Our findings are a wake-up call,” he says. “Obviously, the environment we inhabit is not good for us. My prime interest as a physician is human beings, and something extremely unhealthy is happening to us, especially to men. We must understand what the causes are, investigate them and change the situation. Right now the human species is like the Titanic a moment before the collision, or maybe already after.”

Swan adds another reason for concern: “Fertility in Western countries is now below ‘replacement.’ That is, in Western countries, couples [on average] have fewer than two children. This means that the number of young people is decreasing at the same time as the population of elderly is growing. There has, therefore, been a ‘demographic shift.’ This poses serious problems for our civilization.”

What sort of future awaits us? Will our children be able to become parents naturally, like us, or are we the last generation?

Levine: “Already, the inability to have children in the natural way is a reality for many of us. Reproduction is a necessary condition for the existence of the human species, and life itself is in concrete danger. We are likely to be the first generation that lives for fewer years than its parents.”

But the world’s population is rising. According to the forecasts, in 2050 there will be nine billion people in the world and 36 million in Israel. How does that jibe with your analysis?

'Right now the human species is like the Titanic a moment before the collision, or maybe already after.'

“The Danish physicist Niels Bohr said that it’s difficult to make predictions, especially about the future. Those predictions take into account the present rate of growth, but not other influences, such as a decline in fertility. Already now, significant percentages of society are suffering from fertility problems, and even higher percentages will suffer from them in the future. I do not rule out the need to plan the size of the human population and to create incentives that will encourage diminished population growth, but the planning should be under our control and not be caused by unhealthy conditions. My goal is not for there to be ever more people in the world, but for those who live here to have a good, healthy life – which is manifestly not the case today.”

Cow’s milk and sperm

One factor for the dramatic decline in the sperm count emerges from a study conducted by Levine and Swan with a group of researchers from Harvard School of Public Health and published in 2015. Its results show that you don’t have to be a farmer to be harmed by pesticides – it’s enough to eat fruits and vegetables tainted by them. This study examined sperm counts of American men who were asked about their consumption of fruits and vegetables. The fruits and vegetables were distributed to groups according to the amount of pesticides used in producing them. The male subjects were also divided up, according to the fruits and vegetables groups. The results showed that the greater the consumption of pesticide-contaminated fruits and vegetables, the lower the sperm count of the men who consumed them; conversely, the fewer pesticide-tainted fruits and vegetables that were eaten, the higher the count of the men consuming them.

“In other words,” Levine explains, “the consumption of fruits and vegetables is beneficial and healthy – provided they do not have a high level of pesticides.”

For her part, Haimov-Kochman is presently conducting research on the connection between the consumption of cow’s milk among adult males and the human sperm count. The study is still under way, but she suspects that the consumption of milk does affect the count. The very fact this research is being carried out shows growing concern over the broad range of potential dangers threatening male fertility.

Endocrine Disrupting Chemicals are linked to the weakening of the reproductive systems of both men and women. It is now known that a group of chemicals called phthalates – which are used to soften plastic and make it more flexible, and are easily released into the environment – are endocrine disruptors since they interfere with endocrine cycles and systems.

According to a 2014 document published jointly by the chief scientist of Israel’s Environmental Protection Ministry and the Public Health Services unit of the Health Ministry, “In laboratory animals it was found that exposure to phthalates affects the reproductive system and has effects on health, such as: interfering with the natural function of the hormonal system, the appearance of congenital defects in the reproductive system and the genitals, low testosterone levels in the stages of sexual maturation, early sexual maturation in females, a low sperm count in adults, low birth weight and premature birth

“In the past decade, studies conducted on human beings have begun to be published that show similar results to those found in laboratory animals It was found that phthalates are liable to affect the sexual development of humans, and there is initial evidence that exposure to them is also liable to affect brain development in humans.”

Plastic Coke bottles.Credit: Vincent Mundy/Bloomberg

Unfortunately, phthalates are everywhere. They are used as coating for medicines and food supplements, and they can be found in construction materials, detergents, medical devices, food products, textiles, carpets, cleaning materials, nail polish, liquid soap, electronic products, meat, milk and more. In Israel, there are only two regulations on the books aimed at reducing exposure to phthalates: one that limits its use in toys, the other in food packaging materials.

Count the number of plastic products you’ve touched in the past hour, and you’ll get an inkling of your exposure to these chemicals. Results of a study published by the Health Ministry in 2014 showed 10 of the 11 types of phthalates were found in the urine of 98 percent of those tested, and that all 11 were found in 92 percent of the urine samples. Phthalates are also known to pass through the placenta and reach the embryo; the first trimester of pregnancy is especially critical for the development of the reproductive system.

Phthalates may also be related to speeding up sexual maturation in girls. In Israel, for example, the probability of menstruating for the first time before the age of 11 is twice as high for girls born after 1978 than it was among those born before 1970.

“We are allowing commercial firms to do as they please, without taking responsibility for the implications of their actions for the health of us all and for the environment,” Prof. Levine asserts. “We need to hold them responsible for what they do.”

The question is, who will be the first to pick up the gauntlet and file a class-action suit against a corporation that, for example, manufactures or uses phthalates – the list is very long, one only has to choose – or against government officials who allow them to do so?

Cherchez la femme

'It’s not a good sign when a biological species can’t reproduce naturally.'

It’s odd that, while male fertility has been undergoing this great drama in the past few decades, it’s the reproductive systems of women that – for good or for ill – has been getting the most attention among medical practitioners and in society in general. Most women visit a gynecologist at some stage in their lives. In contrast, few men are in contact with a urologist. A study conducted in Canada in 2016 found that men were able to identify only 50 percent of the likely causes of a decline in sperm production. Many, for example, did not realize that obesity could cause a reduced sperm count (according to various studies, obese men have a lower count than non-obese ones).

A Newsweek cover story in September noted that the women’s fertility industry is valued at close to $21 billion a year in the U.S., and includes medical treatments, alternative treatments, apps, special sports activities, fertility-boosting diets and more. This state of affairs makes it seem as though women are exclusively responsible for fertility. However, according to the American Society for Reproductive Medicine, Newsweek reported, in 40 percent of cases the men are responsible for infertility.

The dialogue focuses largely on women’s biological clocks, but the male clock is ticking, too. The Newsweek article cites a recent study conducted by the Beth Israel Deaconess Medical Center, which found that of thousands of IVF attempts in the Boston area, “women under the age of 30 with a male partner between 40 and 42 were significantly less likely to give birth than those whose male partner was between 30 and 35.” It’s not only the sperm count that declines in men beginning in their mid-30s, the quality of the sperm does too. It’s also understood today that phenomena that in the past were thought to be associated solely with the age of the pregnant woman, such as autism or schizophrenia in newborns, are also related to the age of her male partner.

“It infuriates me that when a couple with a fertility problem turns to the health system for help, the first thing they do is check the woman and place the whole burden of fertility on her,” Levine says. “And it’s even more infuriating that strategies of promoting health and preventive medicine, such as giving up smoking, healthy nutrition and physical activity by the couple aren’t tried before resorting to medical interventions. In some fertility treatment cases, it’s possible to become pregnant in the natural way, but today it’s customary to focus only on medical solutions.”

Levine is appalled by the thought that the continuation of human civilization will be absolutely dependent on technology. “It’s not a good sign when a biological species can’t reproduce naturally. Fertility treatments should come at the end of the pipeline, not in mid-flow. We in Israel are world champions at injecting sperm into an egg, but very bad at understanding the connection between the environment and fertility. Basing ourselves on technology to bring life into the world will lead us to disaster, because I think that the technological solutions are not good for society in the long run. In addition, if the number of sperm cells falls, it’s a logical assumption that the quality of the individual sperm is also not as good.”

The focus on women is infuriating for another reason, too. Like blood pressure, the sperm count can be a tool used in predicting a man’s health – it can even constitute a warning of premature death. A 2015 study, also quoted in the Newsweek report, found that infertile men were more likely to suffer from heart disease and diabetes, or, according to another study, cancer.

“It’s like the canary in the coal mine,” Levine says. “Men with a low sperm count have a higher potential for hospitalization, mortality and disease. It’s possible that the same disease – diabetes, say – causes both a decline in the sperm count and is also related to the heightened risk of hospitalization. It could be that a hitch in early pregnancy caused the embryo to have both a low sperm count and diabetes. We don’t know how the connection between health and the sperm count is created, but we do know that it exists.”

An early indication that a species is facing extinction (if it does not occur by means of its mass killing by another species) is the loss of the ability to reproduce. Is this where the human species is headed? There have already been five instances of mass extinctions throughout human history (or seven, according to another theory). Some biologists think we may be in the midst of a sixth extinction (or an eighth, according to the second count). In the previous extinctions, 75 percent of the species on the planet disappeared. In this connection, we are almost there: According to various estimates, 50 percent of all species of flora and fauna have become extinct in the modern era in the wake of human activity.

With our arrogance, we believe that we will not be affected, but many scientists warn otherwise. There are increasing indications that show that the magnificent human species, too, will vanish into oblivion together with the world it is destroying. A low sperm count is just one more signpost along the way.

What men can do

The causes of the dramatic decrease in male fertility in the Western world over the past four decades are many and varied. This worrisome trend is a wake-up call for the human species to stop submissively accepting the dangerous substances unleashed in our water, land and air, and for governments to take action to protect the public’s health. But until that happens, here are a few modest tips that can contribute to individual health:

Engage in physical activity and spend less time sitting. A 2013 study showed that men who engaged in sports and spent less time sitting had a sperm count that was 73 percent higher than less active men.

Watch less television. An American study demonstrated that men who watched 20 hours or more a week had a lower sperm count than those who didn’t watch television.

Don’t carry a cellphone in your pocket, don’t place a laptop on your knees and avoid tight-fitting undergarments. Those are all sources of heat, and studies have indicated a connection between heat near the pubic region and a decline in sperm count. There are also theories associating non-ionizing radiation, such as emanates from cellphones and computers, with a lower count.

Maintain proper body weight, eat a balanced diet and reduce consumption of processed foods. Studies have shown that men who stuck to a regimen of healthful food and maintained proper weight had higher sperm counts than those who were not careful about what they ate.

Don’t heat food in plastic containers, bags or takeaway food packages. Studies of mice have demonstrated a connection between phthalates, which are found in plastics and released in the course of heating, and adverse effects on fertility.

Avoid cosmetic products that contain DBP and DEHP, and also plastic products containing PVC. Choose plastic products with a recycling code that is not 3 or 7, as they tend to contain more phthalates.

Don’t smoke or consume a lot of alcohol, and avoid steroids in high dosages. Studies have shown that users of these products have a lower sperm count in comparison to those who avoid them.

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