Could This Male Health Problem Spell the End of the Human Race?

There is a crisis in male health. Learn what it is and how scientists plan to overcome it.

There are lots of theories on what might annihilate the human race. An asteroid the size of Texas, the super volcano under Yellowstone, or if we survive an incredibly long time, the expansion of our sun. Unmitigated climate change is the disaster de jour. There could be a worldwide pandemic, although that’s unlikely to eliminate all seven billion of us. The threat of nuclear war still hangs over our heads. But one place that is hardly even talked about is men’s health, particularly the health of their sperm. The quality of male sperm has declined significantly in developed countries for the last fifty or sixty years . The reason has continued to stymie researchers for decades.


Sperm count, what is actually called sperm concentration, has dropped even among younger men. A man’s concentration must be 15 million sperm per milliliter or more. Below this point he is considered subfertile. Also, things like motility—its ability to swim vigorously in order to reach the egg, DNA formation, and even the size and shape of sperm are all incredibly important when it comes to conception. These qualities have declined as well. One French study, conducted between 1989 and 2005, and including 26,000 men, found that sperm counts dropped by one-third over the sixteen year period . Sperm quality also declined by a similar margin. The decrease was progressive—meaning it is probably still ongoing. Some studies point to sperm quality declining for at least the last century.

Gary Cherr is a reproductive toxicologist at the University of California, Davis. He says men in industrialized countries are producing poorer sperm than our primate cousins and other mammals. Among the most fertile men such an issue are still prominent, according to Cherr. In a recent European study, 20% of young men were found to be subfertile. This trend may be driving the recent popularity in fertility procedures, such as vitro fertilization (IVF). The rate of testicular cancer worldwide over the last 30 years has also doubled, and researchers wonder if there is a connection.

Though there still is no clear understanding of what is causing sperm’s decline, theories abound. Toxins in the environment such as endocrine disruptors (like PCBs), industrial waste, and agricultural chemicals—pesticides and fertilizers have all been blamed. One study found that industrially produced aluminum in the environment, first introduced as a consumer product around the same time the decline started, could be the culprit. Other suspects include exposure to radiation through electronic devices, a high fat diet, lack of exercise and a more sedentary lifestyle, and the obesity epidemic. Couples are also having children later in life, further affecting fertility.

It is estimated that 219,000 couples in the U.S. struggle with fertility issues, or 15% of the total. Half the time, the problem originates from the male side of the equation, but this could vary between 20-70%. For those couples trying to conceive, urologists say men should exercise, eat right, avoid tobacco and alcohol, and control stress. The healthier the father-to-be is, the healthier his sperm. Prescription and even non-prescription drugs can also have an effect.

There are other problems. DNA damage can obstruct fertilization. The Y-chromosome is programmed to naturally degrade over time. Then there is a coating that protects the sperm in the hostile environment it must travel through. Some men have a genetic mutation that inhibits the growth of this shell. Recently, a study found that a receptor on the sperm’s tail picks up progesterone from the egg, giving it a “power kick .” This causes the tail to whip vigorously, helping the sperm to push through the final distance and cut through the egg’s protective coating. Some men may be missing this receptor.

Though women often deride men as simple creatures, their biology has proven anything but, and fertility medicine on the male side has lagged. Even so, besides freezing healthy sperm, researchers are starting to make dramatic breakthroughs which could help protect against the sperm crisis reaching a critical level. For instance, Chinese scientists recently announced they were able to produce artificial mouse sperm in a lab. Though some scientists remain unconvinced, and the fact that mice are one thing, humans another, the seeds so to speak for a technological fix are there. Changes in social policy, tighter consumer protections, and environmental safeguards could further boost the quality of sperm. Experts say that although science is working on isolating a reason and offering solutions, conceiving a child the old fashioned way, without the interference of medicine, is still the best method.

To learn more about lab created sperm click here: 

Will China’s green energy tipping point come too late?

Pay attention to the decisions made by the provinces.

Surprising Science
  • China leads the world in numerous green energy categories.
  • CO2 emissions in the country totaling more than all coal emissions in the U.S. have recently emerged.
  • This seems to be an administrative-induced blip on the way towards a green energy tipping point.
Keep reading Show less

Got a question for a real NASA astronomer? Ask it here!

NASA astronomer Michelle Thaller is coming back to Big Think to answer YOUR questions! Here's all you need to know to submit your science-related inquiries.

Surprising Science

Big Think's amazing audience has responded so well to our videos from NASA astronomer and Assistant Director for Science Communication Michelle Thaller that we couldn't wait to bring her back for more!

And this time, she's ready to tackle any questions you're willing to throw at her, like, "How big is the Universe?", "Am I really made of stars?" or, "How long until Elon Musk starts a colony on Mars?"

All you have to do is submit your questions to the form below, and we'll use them for an upcoming Q+A session with Michelle. You know what to do, Big Thinkers!

Keep reading Show less

The value of owning more books than you can read

Or how I learned to stop worrying and love my tsundoku.

(Photo from Wikimedia)
Personal Growth
  • Many readers buy books with every intention of reading them only to let them linger on the shelf.
  • Statistician Nassim Nicholas Taleb believes surrounding ourselves with unread books enriches our lives as they remind us of all we don't know.
  • The Japanese call this practice tsundoku, and it may provide lasting benefits.
Keep reading Show less

Take the Big Think survey for a chance to win :)

Calling all big thinkers!

  • Tell us a little bit about where you find Big Think's videos, articles, and podcasts.
  • Be entered for a chance to win 1 of 3 Amazon gift cards each worth $100.
  • All survey information is anonymous and will be used only for this survey.
Keep reading Show less
(Photo: ANGELA WEISS/AFP/Getty Images)
Culture & Religion
  • The next Mega Millions drawing is scheduled for Oct. 23 at 11 pm E.T.
  • The odds of any one ticket winning are about 1 in 300 million.
  • This might be a record-setting jackpot, but that doesn't mean you have a better chance of winning.
Keep reading Show less

How to raise a non-materialistic kid

Money makes the world go 'round. Unfortunately, it can make both children and adults into materialists.

Robert Collins / Unsplash
Personal Growth
  • Keeping a gratitude journal caused children to donate 60 percent more to charitable causes.
  • Other methods suggested by researchers include daily gratitude reflection, gratitude posters, and keeping a "gratitude jar."
  • Materialism has been shown to increase anxiety and depression and promote selfish attitudes and behavior.
Keep reading Show less

Elon Musk's high-speed test tunnel will give free rides on Dec. 11

The Boring Company plans to offer free rides in its prototype tunnel in Hawthorne, California in December.

Image: Getty Images/Claudia Soraya
Technology & Innovation
  • The prototype tunnel is about 2 miles long and contains electric skates that travel at top speeds of around 150 mph.
  • This is the first tunnel from the company that will be open to the public.
  • If successful, the prototype could help the company receive regulatory approval for much bigger projects in L.A. and beyond.
Keep reading Show less

Cancer researcher says keto is not a fad diet

Anatomy and physiology professor David Harper claims a recent study in The Lancet is flawed.

Photo: Shutterstock
Surprising Science
  • The low-carbohydrate group in a recent Lancet study were typically middle-aged, obese, sedentary, diabetic smokers.
  • The study was not a randomized, controlled, double-blind experiment.
  • Harper has been in ketosis for six years, and says it has profound effects on cancer patients, among other chronic ailments.
Keep reading Show less