An estimated 1 in 6 people suffer from infertility—the inability to conceive after a minimum of 12 months of regular, unprotected sexual intercourse—worldwide, according to the World Health Organization. Historically, the burden of infertility has overwhelmingly been placed on women; however, researchers are becoming increasingly aware that often both male and female factors contribute to infertility. Here, let’s explore the effect exposure to endocrine-disrupting chemicals (EDCs) may be having on male fertility.
How do we measure male fertility?
We’ve previously shared the impact of sperm quality, quantity, and motility on male fertility, here. To assess sperm health, specialists will look at sperm shape (e.g., do the sperm have a long tail and oval-shaped head?) plus motility (i.e., their ability to travel from the testicles through the penis, and later through the woman’s vagina, cervix, and fallopian tubes) plus count (the number of normal sperm present). While estimates vary, a sperm count of 20 million sperm per millimeter of semen or higher is considered sufficient to ensure that enough sperm can survive the acidic environment of a woman’s vagina to make conception possible [1]. A lower sperm count is consistent with decreased fertility. However, because it only takes one sperm for pregnancy to occur, a low sperm count does not mean pregnancy is impossible—just less likely.
We also previously discussed how multiple studies since the 1990s have found demonstrable decreases in sperm counts and those declines continue to this day [1]. Additionally, male reproductive diseases which can lead to infertility, such as testicular cancer, are on the rise across Western countries.
What are endocrine-disrupting chemicals?
As defined by this 2023 research review, an endocrine disruptor is “a chemical substance that can interfere with the functioning of the endocrine system of humans or animals and cause adverse health effects in an organism or its progeny” [2].
Basically, endocrine disruptors are chemicals that imitate our natural hormones, primarily our sex hormones, including estrogen. Because our sex hormones affect every system in our body, these “fake” hormones consequently affect our whole bodies, potentially sending confusing signals and adversely affecting our fertility, development, immunity, and overall health and well-being. Furthermore, “these effects may occur at very low doses” [2][3]. The estrogenic effects of some endocrine-disrupting chemicals (endocrine disruptors that function this way are called xenoestrogens) may be particularly damaging to male fertility.
Endocrine-disrupting chemicals can be found in plastics, food packaging, beauty and hygiene products, pesticides, flooring, paint, toys, and cleaning products, just to name a few common sources. Some common EDCs include phthalates, bisphenol A (BPA), pesticides, and parabens. Importantly, as the 2023 research review found, “In some cases, the effects may be reversible if exposure to the EDC is stopped, but in other cases, the effects may be permanent” [2].
How might endocrine-disrupting chemicals be connected to male infertility?
Endocrine-disrupting chemical exposure may contribute to male infertility in several ways [4]. EDC exposure can impact testicular development, sperm count, quality, motility, and DNA integrity. However, as this 2019 review explains, more research needs to be done to confirm the extent of the effects of specific endocrine-disrupting chemicals, because there are multiple categories of EDCs and different studies have reached different conclusions [4]. Let’s look at what we know specifically about phthalate, BPA, pesticide, and paraben exposure in relation to male infertility.
Phthalates
Phthalates, also known as plasticizers, are manufactured chemicals found in plastics, sealants, shower curtains, vinyl flooring, hygiene and cleaning products, and makeup. Because plastic is often used for food packaging, it can be found in many foods and drinks. We have previously written on phthalates’ in-utero effects. For unborn males specifically, phthalate exposure has been demonstrated to affect testicular development. However, it is important to note that phthalates are just as harmful for males of all ages. Phthalate exposure has been associated with poor semen quality and an increased risk for testicular cancer, though researchers have not established how much is too much exposure [4].
Of note, some occupations expose adult males to high amounts of phthalates. An example of this is firefighting, as firefighter gear and flame retardant foam contain phthalates. Because phthalate absorption increases with heat and exercise, firefighters’ increased risk of testicular, prostate, and other cancers is unsurprising, though very concerning [5].
BPA
BPA stands for Bisphenol A. It is another chemical frequently found in plastics [4]. It is also used in household products, aluminum cans, medical supplies, and dental sealants. BPA exposure is higher when BPA-containing products, such as food containers, are heated. BPA exposure is associated with decreased sperm count, motility, and quality [4].
Pesticides
Pesticides are chemicals that include herbicides, insecticides, and fungicides. They are used to kill bugs, bacteria, and other “pests.” Pesticides are frequently used in all phases of food production and are a major worldwide concern. We come into contact with pesticides through our food, water, and air and ground pollution, to name a few areas. Pesticides have been associated with lowered sperm count, reduced motility, and abnormal morphology, meaning that the appearance of the sperm under a microscope is abnormal [4].
Parabens
Parabens are preservatives often found in hygiene products like deodorant, beard balms, and cologne. They are also used in processed foods like store-bought bread products. Paraben exposure is associated with lower pregnancy outcomes in couples trying to conceive, but more research is needed to clarify the specific areas of the endocrine system that parabens affect [4].
What can men do to reduce EDC exposure?
EDCs are everywhere, and it can feel like too great a task to escape their effects. The good news is that there are always ways to limit one’s exposure. Here are some basic ways to reduce your exposure to EDCs.
- Filter your water with a reverse osmosis filtration system to remove birth control pill residue and other estrogens found in tap water.
- Switch out your plastic containers, including disposable plastic water bottles, to glass or stainless steel.
- Avoid microwaving your plastic containers, as exposure to heat increases phthalate and BPA release.
- Choose clothing made of natural fibers like cotton and linen.
- Wash your fruits and vegetables and choose organic foods when possible.
- Check containers for labels saying BPA free, Paraben free, and Pthalate free.
- Avoid scented skin care products, shampoo, beard balms, and cologne, including products with ingredients that simply read ‘fragrance’ or ‘parfum.’
The bottom line on endocrine-disrupting chemicals and male fertility
We often talk about how the female reproductive system affects every area of a woman’s health, but how often do we think about how men’s reproductive hormones affect every area of male health? Men may not have a hormonal cycle that can be seen through a chart, but their hormones are still serving important functions in their bodies, and it is important that we take care of them.
Limiting exposure to EDCs is one way men can take better care of their reproductive and endocrine systems, and thus, care for their overall health. More and more, we’re learning that Dad’s preconception health impacts his child’s health down the road, so decreasing his endocrine-disrupting chemical exposure may have long-lasting benefits even after that positive pregnancy test.
