Tag Archives: male fertility

Image result for human sperm, wikipedia The last post discussed the steep ongoing decline in sperm counts and sperm concentration in men from North America, Europe, Australia, and New Zealand. It mentioned a number of environmental causes that could be contributing to this, including the huge increase of chemicals, especially endocrine disruptors (chemicals that disrupt our hormones) over the past few decades.

But another study was also just published that showed (in mice) that effects of chronic exposure to endocrine disrupting chemicals are amplified over 3 generations - and each generation has even lower sperm counts, sperm concentration, and reproductive abnormalities. So each generation gets progressively worse with continued exposure.

As the researchers state: "Our findings suggest that neonatal estrogenic exposure can affect both the reproductive tract and sperm production in exposed males, and exposure effects are exacerbated by exposure spanning multiple generations. Because estrogenic chemicals have become both increasingly common and ubiquitous environmental contaminants in developed countries, the implications for humans are serious. Indeed, it is possible effects are already apparent, with population-based studies from the U.S., Europe, Japan, and China reporting reductions in sperm counts/quality and male fertility within a span of several decades." Yikes...

The World Health Organization (WHO) considers an impairment in ability to fertilize an egg at 40 million sperm per milliliter or below, and the level where WHO considers fertilization unlikely is 15 million sperm per milliliter. This is why the sperm count study discussed in the last post is so frightening: North American, Canadian, Australian, and New Zealand men  whose partners are not yet pregnant nor do they have children (i.e., they are not confirmed fertile men) have experienced a drop in average sperm count of about 50 percent over four decades, to 47 million sperm per milliliter. Niels Skakkebæk, a Danish pediatrician and researcher working on this topic said: "Here in Denmark, there is an epidemic of infertility."and "Most worryingly [in Denmark] is that semen quality is in general so poor that an average young Danish man has much fewer sperm than men had a couple of generations ago, and more than 90 percent of their sperm are abnormal." Uh-oh...What will it take for governments to address this serious issue?

In the meantime, see the last post for some tips on how to reduce your own exposure to endocrine disrupting chemicals. Just note that you can reduce exposure, but you can't totally eliminate exposure. Excerpts from Environmental Health News:

Science: Are we in a male fertility death spiral?

Margaret Atwood's 1985 book, The Handmaid's Tale, played out in a world with declining human births because pollution and sexually transmitted disease were causing sterility. Does fiction anticipate reality? Two new research papers add scientific weight to the possibility that pollution, especially endocrine disrupting chemicals (EDCs), are undermining male fertility.

The first, published Tuesday, is the strongest confirmation yet obtained that human sperm concentration and count are in a long-term decline: more than 50 percent from 1973 to 2013, with no sign that the decline is slowing. "The study is a wakeup that we are in a death spiral of infertility in men," said Frederick vom Saal, Curators’ Distinguished Professor Emeritus of Biological Sciences at the University of Missouri and an expert on endocrine disruption who was not part of either study.

The second study, published last week by different authors, offers a possible explanation. It found that early life exposure of male mouse pups to a model environmental estrogen, ethinyl estradiol, causes mistakes in development in the reproductive tract that will lead to lower sperm counts. According to vom Saal, the second study "provides a mechanistic explanation for a progressive decrease in sperm count over generations." What makes this study unique is that it examined what happened when three successive generations of males were exposed—instead of just looking only at the first. Hunt, in an email, said "we asked a simple question with real-world relevance that had simply never been addressed."

In the real world, since World War II, successive generations of people have been exposed to a growing number and quantity of environmental estrogens—chemicals that behave like the human hormone estrogen. Thousands of papers published in the scientific literature (reviewed here) tie these to a wide array of adverse consequences, including infertility and sperm count decline. This phenomenon—exposure of multiple generations of mammals to endocrine disrupting compounds—had never been studied experimentally, even though that's how humans have experienced EDC exposures for at least the last 70 years. That's almost three generations of human males. Men moving into the age of fatherhood are ground zero for this serial exposure.

So Horan, Hunt and their colleagues at WSU set out to mimic, for the first time, this real-world reality. They discovered that the effects are amplified in successive generations. They observed adverse effects starting in the first generation of mouse lineages where each generation was exposed for a brief period shortly after birth. The impacts worsened in the second generation compared to the first, and by the third generation the scientists were finding animals that could not produce sperm at all. This latter condition was not seen in the first two generations exposed. Details of the experimental results actually suggested that multiple generations of exposure may have increased male sensitivity to the chemical[Original study.]

Image result for human sperm, wikipedia Once again a study (this time a review and meta-analysis of other studies) found an alarming and steep decline in sperm counts in men from Western countries over a 40 year period. This steep decline for both sperm concentration (SC) and total sperm count (TSC) is for men in North America, Europe, Australia, and New Zealand. The sperm count and sperm concentration declined 50 to 60% in the period between 1973 to 2011 - with a downward slope showing a decline of -1.4% to -1.6% per year. On the other hand, men from South America, Asia and Africa did not show a decline.

The authors of the study were very concerned over the results showing this decline in Western countries, with no evidence of the decline leveling off. As these declines continue, more and more men will have sperm counts below the point at which they can reproduce. Instead they will be infertile or "sub-fertile" (with a decreased probability of conceiving a child). The threshold level associated with a "decreased monthly probability of conception" is considered to be 40 million/ml. Shockingly - this study found that in 1973 when Western men who were not selected for fertility, and didn't know their fertility status (e.g., college students, men screened for the military) - the average sperm concentration was 99 million/ml, but by 2011 it was 47.1 million/ml. These men were called "unselected" and are likely to be representative of men in the general population. Men known to be fertile (e.g., had fathered a child) were at 83.8 million/ml in 1976, but were down to 62.0 million/ml in 2011. Both groups had consistent declines year after year.

What about the men from South America, Asia, and Africa? There, studies showed that the "unselected" men (not selected for fertility and who didn't know their fertility status) started out at 72.7 million/ml in 1983, and were at 62.6 million/ml in 2011, while men known to be fertile started out on average at 66.4 million/ml in 1978 and were at 75.7 million/ml in 2011. They did not show the decline of the North American, European, Australian, and New Zealand group of men.

What does this mean? And what is going on? These results go beyond fertility and reproduction. The decline is consistent with other male reproductive health indicators over the last few decades: higher incidence of testicular cancer, higher rates of cryptorchidism, earlier onset of male puberty, and decline in average testosterone levels. Instead, it appears that sperm counts of men are "the canary in the mine" for male health - evidence of harm to men from environmental and lifestyle influences. These Western developed countries are awash in chemicals and plastics, also with endocrine disruptors (hormone disruptors) in our foods, our personal care products, etc - and so studies find these chemicals in all of us (in varying degrees). Same with flame retardants, pesticides, "scented" products. Exposure to all sorts of environmental pollutants - whether in air, water, soil, our food - such as high levels of aluminum. All of these can have an effect on sperm counts and reproductive health. And note that chemicals that can depress sperm counts  are also linked to many health problems, including chronic diseases.

What can I do?  You can lower your exposure to many chemicals (e.g., pesticides), plastics, and endocrine disruptors, but you can't avoid them totally. Yes, it'll mean reading labels and ingredient lists on foods, personal care products (such as soaps, shampoo, lotion), and products used in the home. TRY TO AVOID OR LOWER EXPOSURE TO: phthalates, parabens, BPA, BPS, and even BPA-free labeled products (all use similar chemicals), flame-retardants (e.g., in upholstered furniture and rugs), stain-resistant, dirt-resistant, waterproof coatings, Scotchgard, non-stick cookware coatings, dryer sheets, scented products (including scented candles and air fresheners), fragrances, pesticides in the yard and home, and "odor-free", antibacterial, antimicrobial, anti-mildew products. Don't microwave foods in plastic containers (including microwave popcorn bags). 

INSTEAD: Try to eat more organic foods, look for organic or least-toxic Integrated Pest Management (IPM) alternatives for the home and garden. Store foods as much as possible in glass, ceramic, or stainless steel containers. Buy foods, if possible, that are in glass bottles - not cans (all lined with endocrine disrupting chemicals) and not plastic bottles or containers (plastics leach). Some people use water filters because there are so many contaminants in our water, even if they meet federal guidelines on "allowable levels" in the water. Avoid cigarette smoke or smoking. Try to lose weight if overweight. Open windows now and then in your residence to lower indoor air pollution. The list is long - yes, a lifestyle change! (see posts on ENDOCRINE DISRUPTORS, FLAME RETARDANTS, and PESTICIDES)

From Medical Xpress: Study shows a significant ongoing decline in sperm counts of Western men

In the first systematic review and meta-analysis of trends in sperm count, researchers from the Hebrew University-Hadassah Braun School of Public Health and Community Medicine and the Icahn School of Medicine at Mount Sinai report a significant decline in sperm concentration and total sperm count among men from Western countries.

By screening 7,500 studies and conducting a meta-regression analysis on 185 studies between 1973 and 2011, the researchers found a 52.4 percent decline in sperm concentration, and a 59.3 percent decline in total sperm count, among men from North America, Europe, Australia and New Zealand who were not selected based on their fertility status. In contrast, no significant decline was seen in South America, Asia and Africa, where far fewer studies have been conducted. The study also indicates the rate of decline among Western men is not decreasing: the slope was steep and significant even when analysis was restricted to studies with sample collection between 1996 and 2011.

The findings have important public health implications. First, these data demonstrate that the proportion of men with sperm counts below the threshold for subfertility or infertility is increasing. Moreover, given the findings from recent studies that reduced sperm count is related to increased morbidity and mortality, the ongoing decline points to serious risks to male fertility and health.

"Decreasing sperm count has been of great concern since it was first reported twenty-five years ago. This definitive study shows, for the first time, that this decline is strong and continuing. The fact that the decline is seen in Western countries strongly suggests that chemicals in commerce are playing a causal role in this trend," Dr. Shanna H Swan, a professor in the Department of Environmental Medicine and Public Health at the Icahn School of Medicine at Mount Sinai, New York.

While the current study did not examine causes of the observed declines, sperm count has previously been plausibly associated with environmental and lifestyle influences, including prenatal chemical exposure, adult pesticide exposure, smoking, stress and obesity. Therefore, sperm count may sensitively reflect the impact of the modern environment on male health across the lifespan and serve as a "canary in the coal mine" signaling broader risks to male health. [Original study.]

Image result for human sperm, wikipedia Human sperm. Credit: Wikipedia

The evidence keeps growing of health effects with BPA exposure, especially during pregnancy and childhood. To minimize BPA exposure try to use glass instead of plastic. Try to drink from and store liquids in glass containers, and do not microwave food in plastic dishes. From Medical Daily:

BPA Disrupts Sperm Production In Mice, Could Be Linked To Decreased Fertility In Men

BPA, or bisphenol A, is a chemical component of plastic that is often found in plastic food containers, plastic bottles, and thermal receipts. Now, a new study shows a direct link between this chemical and disrupted sperm production in mice. BPA disrupts the delicate DNA interactions needed to create sperm, say the Washington State University researchers.

Sperm counts have declined over the past few decades worldwide, scientists warn. In Denmark, more than 40 percent of young men have sperm counts in the infertility or decreased fertility range. Reports from other European countries, Japan, and the United States all tell the same story. Sperm counts, though, may be only the tip of the iceberg. Studies also document an increase in abnormalities of male reproductive organs, including undescended testicles, hypospadias (when the urethra opening is misplaced on the penis), and increased incidence of testicular cancer — a constellation of male disorders referred to as testicular dysgenesis syndrome. This syndrome is thought to result from exposure, during early development, to estrogens. BPA is an endocrine disrupting chemical with estrogenic activity. Could descending sperm counts and testicular dysgenesis syndrome be linked to early exposures to this chemical?

Hunt and her colleagues gave newborn male mice oral doses of BPA. They also exposed another group of mice to the synthetic estrogen, ethinyl estradiol, which is used in many formulations of hormonal contraceptives (such as birth control pills). They also exposed another group of mice to a placebo. ..The team discovered that the sperm of BPA exposed mice did a poorer job of meiosis, the process by which cells combine the genetic information of their parents. As a result, more sperm died."We have a window of just a few days and we permanently change the way that the testis makes sperm in the adult," says Hunt.Hunt worries that sperm counts will continue to go down with each exposed generation. 

Same study, but this write-up has more background. From Environmental Health News:

BPA exposure linked to changes in stem cells, lower sperm production

The study, published online today in PLoS Genetics, is the first to suggest that low, brief exposures to bisphenol-A, or other estrogens such as those used in birth control but found as water contaminants, early in life can alter the stem cells responsible for producing sperm later in life...These exposures – comparable to human exposures to the compounds -- caused “permanent alterations” to the stem cells responsible for sperm production, the authors wrote.

Something to think about if you are considering fathering a child.From Medical Xpress:

Study links ultraviolet filters to pregnancy delays

Certain sunscreen chemicals used to protect against ultraviolent rays may impair men's ability to father children in a timely manner, according to a study by the National Institutes of Health and the New York state Department of Health's Wadsworth Center. But the researchers caution that the results are preliminary and that additional studies are needed to confirm their findings.

Benzophenone (BP)-type ultraviolet (UV) filters comprise a class of about 29 chemicals commonly used, among other purposes, in sunscreens and other personal care products to protect skin and hair from sun damage. Some of these chemicals, upon being absorbed by the skin, can interfere with the body's hormones and endocrine system processes. Researchers found that men with high exposure to UV filters BP-2 or 4OH-BP had a 30 percent reduction in fecundity, the biological ability to reproduce. Lower fecundity may result in a longer time to pregnancy.

"In our study, male fecundity seems to be more susceptible to these chemicals than female fecundity. The women participants actually had greater exposure to the UV filters overall, but their exposure wasn't associated with any significant pregnancy delays," said Germaine Louis, Ph.D., director of the Division of Intramural Population Health Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development. 

The researchers studied 501 couples that were trying to conceive a child. The couples were part of the Longitudinal Investigation of Fertility and the Environment (LIFE) study, established to examine relationships among fertility, lifestyle factors, and exposure to environmental chemicals. Researchers recruited the study participants from 16 counties in Michigan and Texas in 2005 through 2009. The women participants ranged from 18 to 44 years of age, and the men were over 18; none had a medical diagnosis of infertility.

The researchers followed the couples until pregnancy or up to one year of trying, to record the time it took for the women to become pregnant...Their findings suggest that some, but not all, UV filters may be associated with diminished fertility in men, independent of their partners' exposure. The researchers observed effects among men with the highest exposure (the 75th percentile and above) to UV filters BP-2 or 4OH-BP.

"But men who are concerned about fertility may be interested in other ways to reduce their exposure to benzophenone UV filters—whether by cutting back on other products that contain the UV filters or by washing after returning indoors."

Earlier research findings from the LIFE Study have linked reduced fertility to high cholesterol levels in women and couples and to high concentrations of phthalates and Bisphenol A (BPA) in men.

Some recent research on sperm quality and implications for fertility. All from Science Daily:

Exposure to aluminum may impact on male fertility, research suggests

Research from scientists in the UK and France suggests that human exposure to aluminum may be a significant factor in falling sperm counts and reduced male fertility.Fluorescence microscopy using an aluminum-specific stain confirmed the presence of aluminum in semen and showed aluminum inside individual sperm.And the team of scientists, at the universities of Lyon and Saint-Etienne in France and Keele in the UK, found that the higher the aluminum, the lower sperm count.

Professor Exley said: "There has been a significant decline in male fertility, including sperm count, throughout the developed world over the past several decades and previous research has linked this to environmental factors such as endocrine disruptors"..."Human exposure to aluminum has increased significantly over the same time period and our observation of significant contamination of male semen by aluminum must implicate aluminum as a potential contributor to these changes in reproductive fertility."

Stress degrades sperm quality, study shows

Psychological stress is harmful to sperm and semen quality, affecting its concentration, appearance, and ability to fertilize an egg, according to a study. It is not fully understood how stress affects semen quality. It may trigger the release of steroid hormones called glucocorticoids, which in turn could blunt levels of testosterone and sperm production. Another possibility is oxidative stress, which has been shown to affect semen quality and fertility.

Twenty hours of TV a week linked to almost half sperm count of those who watch little TV

Healthy young men who watch TV for more than 20 hours a week have almost half the sperm count of men who watch very little TV, indicates a new study.

Cell phones negatively affect male fertility, new study suggests

Men who keep a cell phone in their pant pocket could be inadvertently damaging their chances of becoming a father, according to a new study. Previous research has suggested that radio-frequency electromagnetic radiation (RF-EMR) emitted by the devices can have a detrimental effect on male fertility. Most of the global adult population own mobile phones, and around 14% of couples in high and middle income countries have difficulty conceiving.

In control groups, 50-85% of sperm have normal movement. The researchers found this proportion fell by an average of 8 percentage points when there was exposure to mobile phones. Similar effects were seen for sperm viability. The effects on sperm concentration were less clear. 

Moderate weekly alcohol intake linked to poorer sperm quality in healthy young men

Moderate alcohol intake of at least 5 units every week is linked to poorer sperm quality in otherwise healthy young men, suggests research. And the higher the weekly tally of units, the worse the sperm quality seems to be, the findings indicate, prompting the researchers to suggest that young men should be advised to steer clear of habitual drinking.

Sperm size, shape in young men affected by cannabis use

Young men who use cannabis may be putting their fertility at risk by inadvertently affecting the size and shape of their sperm, according to new research. In the world's largest study to investigate how common lifestyle factors influence the size and shape of sperm, a research team found that sperm size and shape was worse in samples ejaculated in the summer months, but was better in men who had abstained from sexual activity for more than six days.