Kiwi men on track to have zero viable sperm by 2040 – scientist
26 February, 2021
A scientist studying human fertility has warned Kiwi men’s sperm counts are dropping so rapidly, within a couple of decades there might be none left.
In 2017, Shanna Swan – an epidemiologist at Icahn School of Medicine at Mount Sinai, New York – co-authored research looking at falling sperm counts in New Zealand, Australia, Europe and North America.
Looking at 185 studies dating back to 1973, Dr Swan and her team found a 50-60 percent decline between 1973 and 2011.
It was sparked by a paper she saw while on sabbatical.
“I spent six months… looking in detail to see, was this decline due to different method of measuring sperm, or recruiting men, or where they more obese or did they smoke more?” she told Environmental Health News this week, promoting the release of her new book .
“Were there other things that could explain the decline? After six months of work, the answer was no. The slope had not changed after all that analysis.”
So she started the proper research that would result in the shocking 2017 paper published in journal – which found the decline was indeed real, consistent and showing no signs of slowing down.
Dr Swan says at current trends, it’s on track to hit zero between 2040 and 2045.
“What does that mean? These are median sperm counts – which means half the men in Western countries will have no sperm. This is a big problem, if it were to come to that… If things continue in the same way, it looks very grim for our population survival.”
Similar drops in sperm quantity weren’t seen in men from South America, Asia and Africa – the scientists unsure whether that was significant, or just because they didn’t have enough data from those regions.
So what’s behind the drop in Western men’s virility? The initial study didn’t go into that, but she does in the book.
“I think everyone agrees this is not genetics – this is too fast for an evolutionary change, we’re talking about 40 or 50 years,” she told Environmental Health News, saying that environmental and lifestyle factors are likely to blame – including the effects of pesticides, cosmetics, foam furniture, paper plates, work stress, fatty food, processed food and packaging.
“The chemicals I’m particularly interested in… are those that affect the body’s hormones. The reason is that reproduction depends on healthy hormones. Anything that would interfere with the body’s natural hormone system… is going to challenge the reproductive system.”
“If women want to have a baby, they are often told, ‘Clean up your act,’ ” Dr Swan writes in the book. “But it’s probably more important for men to do so.”
Of course none of this is new.
We are starting to reap the consequences of something that was warned about a quarter of a century ago.
This book is just as seminal as Rachel Carson’s Silent Spring, but far less-known
Our Stolen Future: Are We Threatening Our Fertility, Intelligence and Survival? A Scientific Detective Story
“A critically important book that forces us to ask new questions about the synthetic chemicals that we have spread across this earth.”—former vice president Al Gore, author of An Inconvenient Truth
Our Stolen Future examines the ways that certain synthetic chemicals interfere with hormonal messages involved in the control of growth and development, especially in the fetus.
The developing fetus uses these natural hormonal messages, which come from both from its own hormone system and from its mother, to guide development. They influence virtually all of the growing individual’s characteristics, from determining its sex to controlling the numbers of toes and fingers to shaping intricate details of brain structure.
Scientific research over the last 50 years has revealed that this hormonal control of development is vulnerable to disruption by synthetic chemicals. Through a variety of mechanisms, hormone-disrupting chemicals (also known as endocrine disrupting chemicals or endocrine disruptors) interfere with the natural messages and alter the course of development, with potential effects on virtually all aspects of bodily function.
Our Stolen Future explores the scientific discovery of endocrine disruption. The investigation begins with wildlife, as it was in animals that the first hints of widespread endocrine disruption appeared. The book then examines a series of experiments examining endocrine disruption of animals in the laboratory which show conclusively that fetal exposure to endocrine disrupting chemicals can wreak life-long damage. These experiments also reveal some of the biological processes by which these chemicals have their effects, and that endocrine disruption effects can be caused by exposure to infinitesimally small amounts of contaminant. Moving from animals to people, Our Stolen Future summarizes a series of well-studied examples where people have been affected by endocrine disrupting chemicals, most notably the synthetic hormone dietheylstilbestrol (DES), to which several million women were exposed through misguided medical attempts to manage difficult pregnancies in the 1950s, ’60s and ’70s.
Our Stolen Future then asks a broader, more difficult and more controversial set of questions. Given what is known from wildlife and laboratory studies, and from examples of well-studied human exposure, and given that exposure to endocrine disrupting chemicals in the real world is widespread at levels comparable to those sufficient to cause animal harm, what effects should health scientists be looking for in people in general? Effects to be expected include declines in fertility and other impacts on the reproductive system of both men and women, impairments in disease resistance, and erosions in intelligence.
Reinventing the wheel?
Here is a contemporary study on glyphosate
In stunning revelations from a study on female mice from the Department of Animal Science at Iowa State University it was revealed that ovarian weight and follicle number were altered at a glyphosate dose level of 2 mg/kg and that chronic low-level exposure to glyphosate altered the ovarian proteome, which could ultimately impact ovarian function.
We received the following text from a friend:
Fyi these are not your standard Roundup (glyphosate)
While Roundup is a nasty piece of work for chronic stuff,
these are next level for acute effects