Is Modern Life Affecting Fertility? Exploring the Science Behind the Growing Fertility Crisis

Most people blame bad luck for infertility, but the research keeps pointing somewhere else entirely.

Let's explore what I’ve been reading about the modern fertility crisis, and why so many people around me are struggling to conceive. I'm not a doctor, and none of this is medical advice. It's a walk through the research in relation to what I'm observing in my own life.

Endocrine-disrupting chemicals like BPA and phthalates keep coming up in reproductive research. Phthalates hide inside a single word on a label: "fragrance". That one word can represent dozens or hundreds of compounds, which is part of why many fertility clinics won't let you walk in wearing perfume.

Microplastics are another piece of this. A 2024 study found them in every human testis sample examined. Others have detected them in ovarian follicular fluid, blood, placentas, and breast milk.

Then there's food. Diets high in ultra-processed foods have been linked to lower sperm concentration, reduced motility, and poorer morphology. Similar patterns show up in women.

No single cause explains what's happening. That's exactly why I wanted to talk about the cumulative picture.

You’ll Learn:

[0:00] Introduction

[3:41] Declining sperm counts have researchers asking whether human biology itself is changing

[6:04] How endocrine-disrupting chemicals mimic hormones and why sunscreen ingredients started my investigation

[9:10] The BPA replacement pattern where each "safer" chemical turns out just as bad

[12:53] The cocktail effect of applying hundreds of chemicals to your body before breakfast

[17:42] Trust your own eyes over waiting for science, and the copper garden lesson

[21:28] Why oxidative stress damages delicate sperm cells and how antioxidants may help

[23:23] There is no single cause, so return to the fundamentals and tune into your body

Resources Mentioned:

Temporal trends in sperm count: a systematic review and meta-regression analysis of samples collected globally in the 20th and 21st centuries by Levine, H. et al. | Article

Microplastic presence in dog and human testis and its potential association with sperm count and weights of testis and epididymis by Hu, C. et al. | Article

Role of oxidative stress in male infertility by Takalani, N. et al. | Article

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Hello, and welcome back to the Gubba Homestead Podcast. I'm Gubba, and today we're talking about something that has been on my mind a lot lately. It seems like everywhere I look, more and more people are struggling to conceive. Friends. Family. People online. Couples who thought it would happen quickly, only to find themselves years into a journey they never expected to be on.

At the same time, we live in a world that is completely different from the one our grandparents grew up in. We're surrounded by thousands of synthetic chemicals, ultra-processed foods make up a huge percentage of the average diet, synthetic fabrics have become the norm, our drinking water contains contaminants that didn't exist generations ago, and many of us put dozens of ingredients on our skin every single day without ever reading the label.

Now, before we dive into today's episode, I want to make something very clear. I am not a physician, scientist, or fertility specialist. Nothing in today's episode is medical advice. My goal isn't to tell you that one specific thing is causing infertility or that avoiding one product will magically solve it. The human body is incredibly complex, and fertility depends on countless factors including age, genetics, medical conditions, nutrition, lifestyle, and more.

Instead, today I simply want to explore what the published science says. Which concerns are backed by evidence? Which ones are still being debated? And perhaps most importantly, why so many researchers around the world have become interested in how our modern environment may be influencing reproductive health.

Before we get into that, I want to thank the sponsor of today's podcast, which is my small skincare business, Arvoti. It all started with one tallow balm I made for my dad while he was struggling with eczema, and today I have the privilege of helping thousands of people simplify their skincare. I also recently launched my handcrafted Unscented Shampoo Bar, made with just six nourishing ingredients and no added fragrance. If you'd like to check it out, along with my tallow balms, botanical serums, cleansing oils, and handcrafted goat milk soaps, you can visit Arvoti.com.

Now let's get into today's topic.

One thing that's interesting is that fertility isn't just becoming a conversation among couples trying to have children. Many developed countries are now having fewer children than what's needed to maintain a stable population without immigration. It's becoming a trending topic.

Of course, there are many social reasons for this. People are getting married later, having children later, pursuing higher education, building careers first, and facing rising housing costs. Those are all real factors. But researchers have also been asking another question.

What if biology is changing too?

One of the most discussed findings over the past several years has been research looking at sperm counts. In 2022, an international group of researchers published an updated review that combined data from more than 200 studies involving tens of thousands of men.

They reported that average sperm counts have declined substantially over the past several decades in many regions of the world. The researchers also found evidence suggesting that the decline may actually be accelerating rather than leveling off.

Now, this doesn't mean every man today has low sperm counts. Plenty of men remain perfectly fertile. But when scientists look at large populations over time, they're seeing a trend that has raised concern among reproductive health experts.
The next question naturally becomes why.

Unfortunately, there isn't one answer.

Researchers believe there are likely many contributing factors acting together rather than a single cause. Obesity has increased. Physical activity has declined. Sleep quality has changed. Chronic stress has become more common. Average age at parenthood has increased. Smoking, alcohol, certain medications, infections, chronic disease, nutrition, and environmental exposures may all play some role.
Then there's another category that has received enormous attention over the last two decades: endocrine-disrupting chemicals.

If you've never heard that phrase before, endocrine-disrupting chemicals are substances that may interfere with the body's hormone system. Hormones act like chemical messengers. They help regulate everything from metabolism and growth to reproduction and development.

Some chemicals appear capable of mimicking hormones, blocking hormone receptors, or altering how hormones are produced and broken down. Researchers have identified hundreds of chemicals that show endocrine-disrupting activity in laboratory studies, although their effects in humans can vary depending on dose, timing of exposure, genetics, and many other factors.

One of the most familiar examples is BPA, or bisphenol A.

For years BPA was commonly used in plastics, food can linings, and thermal receipt paper. Because BPA can behave somewhat like estrogen under certain conditions, researchers began investigating whether repeated exposure might influence reproductive health.

Since then, hundreds of studies have been published. Animal studies often show measurable hormonal effects, particularly during fetal development and early life.

Human studies are more complicated because people are exposed to countless chemicals simultaneously, making it difficult to isolate one exposure from another. Still, several observational studies have reported associations between higher BPA exposure and changes in sperm quality, hormone levels, ovulation, and fertility outcomes. That doesn't prove BPA causes infertility, but it has been enough to prompt many manufacturers to remove it from products intended for infants and food storage.

Then we have phthalates, another group of chemicals that have become a major focus in reproductive research.

Phthalates are often used to make plastics more flexible, but they're also found in surprising places like fragrances, cosmetics, lotions, shampoos, vinyl flooring, food packaging, and even medical equipment.

One thing I didn't realize until I started reading about them is that companies don't necessarily have to list the individual fragrance chemicals on a label. Often you'll simply see the word "fragrance" or "parfum," and that single word can represent dozens or even hundreds of different compounds. This makes it difficult for consumers to know exactly what they're being exposed to.

Several human studies have found associations between higher phthalate exposure and lower testosterone levels, reduced sperm quality, altered reproductive hormones, and changes in ovarian function.

Another family of chemicals you've probably heard about are PFAS, often nicknamed "forever chemicals."

These compounds earned that nickname because they don't break down easily in the environment. They've been used in non-stick cookware, stain-resistant fabrics, firefighting foams, food packaging, waterproof clothing, and countless industrial applications.

Today, PFAS have been detected in water supplies around the world, wildlife, soil, and even human blood.

Scientists are actively studying whether long-term PFAS exposure may influence fertility, thyroid function, pregnancy outcomes, and reproductive hormones. While researchers continue to debate the strength of certain associations, enough concern exists that governments around the world have begun tightening regulations and reducing allowable levels in drinking water.

One thing that really stands out to me is how difficult these studies are to perform. Imagine trying to determine whether one chemical affects fertility when every participant has different diets, different jobs, different genetics, different lifestyles, different stress levels, and completely different combinations of environmental exposures.

That's why you'll often hear scientists say that these findings are "associated with" reproductive changes rather than proving direct causation.
Still, when multiple studies conducted in different countries continue finding similar patterns, researchers understandably become interested in investigating further.

Another area that's received growing attention is personal care products. Think about your average morning routine. You might use shampoo, conditioner, body wash, a face cleanser, moisturizer, foundation, mascara, perfume, hair spray, deodorant, and body lotion—all before you've even started your day.

By the time many people leave the house, they've applied dozens, sometimes hundreds, of individual chemical ingredients to their bodies before breakfast.

What happens when someone is exposed to small amounts of many different chemicals every single day for decades?

This concept is sometimes referred to as the "mixture effect" or the "cocktail effect." For me personally, that's one reason I became interested in simplifying my skincare routine. Because reducing unnecessary exposures seemed like a reasonable choice that aligned with the way I wanted to live. I like recognizing every ingredient on the label. I like knowing exactly what I'm putting on my skin. It gives me peace of mind.

But skincare isn't the only thing changing in our modern environment. Something else has quietly become almost impossible to avoid, and most of us wear it every single day without giving it a second thought.

Synthetic clothing.

When you really stop and think about it, clothing has changed dramatically in a relatively short period of human history. For thousands of years, people primarily wore natural fibers like linen, wool, cotton, hemp, and silk. Then, over the last century, synthetic materials such as polyester, nylon, acrylic, and spandex became incredibly popular because they're inexpensive to produce, wrinkle resistant, stretchy, and durable.

Today, if you walk through almost any clothing store, a huge percentage of what you'll find is made from synthetic materials, often blended together in ways that would have been unimaginable just a few generations ago.

This has become an area that's receiving a lot of attention because synthetic textiles are one of the largest sources of microplastic fiber pollution. Every time synthetic clothing is manufactured, worn, or washed, tiny plastic fibers can be released into the environment. Those fibers have now been found in oceans, rivers, agricultural soil, household dust, rainwater, seafood, drinking water, and even the air we breathe inside our homes.

What really caught my attention is that these particles aren't just staying in the environment anymore. Over the last few years, studies have identified microplastics in human blood, placentas, breast milk, lung tissue, liver tissue, testes, ovaries, and even the follicular fluid that surrounds developing eggs. That doesn't prove they're causing disease or infertility, but it does tell us they're entering the human body much more extensively than scientists once believed. In fact, a 2024 study published in Toxicological Sciences found microplastics in every human testis sample the researchers examined.

Another study detected them in ovarian follicular fluid, raising important questions about whether these particles could eventually influence reproductive health. Right now, though, those questions remain exactly that—questions.

Laboratory studies have shown that certain microplastics can increase oxidative stress and inflammation in cells, and some animal studies have reported changes in reproductive hormones, sperm quality, ovarian function, and embryo development after high levels of exposure.

Human biology, however, is much more complicated than laboratory experiments. And at this point, it's accurate to say that microplastics are an active area of fertility research, but it would not be accurate to say they've been proven to cause infertility in humans.

Another interesting aspect of clothing has nothing to do with plastics at all—it's heat. Male fertility depends on the testes remaining a few degrees cooler than normal body temperature, which is why they're located outside the body in the first place.

Scientists have known for decades that prolonged heat exposure from things like frequent hot tubs, repeated sauna use, prolonged fevers, or certain occupations can temporarily reduce sperm production. Some experts have also explored whether tight-fitting clothing or less breathable fabrics might contribute to increased temperatures, although the evidence has been mixed and no clear conclusion has been reached. 

Personally, one of the reasons I've gravitated toward natural fibers is because I just genuinely enjoy them. Linen breathes beautifully, wool regulates temperature incredibly well, and cotton simply feels different to me. It's one of those small choices that helps me feel more connected to a simpler way of living, whether or not future research eventually finds measurable health differences.

Another area where the evidence is much stronger is nutrition. If you compare today's grocery store with one from seventy or eighty years ago, the difference is incredible.

Entire aisles are filled with foods that barely resemble their original ingredients. Brightly colored cereals, frozen dinners, packaged pastries, chips, soda, candy, energy drinks, and countless convenience foods have become a normal part of many people's diets.

Researchers refer to many of these as ultra-processed foods because they've undergone extensive industrial processing and often contain ingredients you wouldn't typically use in your own kitchen.

So one trend has shown up again and again. People who eat diets high in ultra-processed foods are more likely to experience obesity, insulin resistance, type 2 diabetes, cardiovascular disease, and chronic inflammation. Those conditions matter because our reproductive system doesn't operate independently from the rest of the body.

Hormones rely on healthy communication between the brain, thyroid, liver, pancreas, adrenal glands, fat tissue, and reproductive organs. When metabolic health begins to suffer, hormone balance often suffers alongside it.
That connection becomes even more interesting when you look specifically at fertility.

A number of observational studies have found that men whose diets are higher in ultra-processed foods tend to have lower sperm concentration, reduced motility, and poorer sperm morphology than men whose diets emphasize more whole foods.

Similar patterns have been observed in women, where dietary patterns rich in whole foods are often associated with better fertility outcomes than diets dominated by highly processed products. These studies don't prove that processed food directly causes infertility, because many lifestyle factors overlap, but they do suggest that the overall quality of our diet may play an important role in reproductive health.

One thing I found especially fascinating while reading through the literature is the role of oxidative stress. Sperm cells are incredibly delicate. Their membranes contain large amounts of polyunsaturated fats, making them particularly vulnerable to damage from oxidative stress.

Too much oxidative stress has been associated with reduced sperm motility, DNA fragmentation, and lower fertilization success. A comprehensive review published in Oxidative Medicine and Cellular Longevity concluded that oxidative stress appears to be one of the major contributors to male infertility and discussed how dietary antioxidants may help support normal reproductive function. That doesn't mean you need one miracle supplement or one so-called superfood.

If anything, the evidence points toward something much simpler: consistently eating a wide variety of fruits, vegetables, herbs, nuts, legumes, and other minimally processed foods that naturally provide the nutrients our bodies need.

Something else that's changed dramatically isn't just what we eat, but where it comes from. Many foods now travel hundreds or even thousands of miles before reaching our plates. They're often harvested before they're fully ripe, transported across continents, stored in warehouses, and eventually displayed in grocery stores for days or weeks.

It's also one of the reasons I fell in love with gardening. There's something incredibly satisfying about walking outside, harvesting vegetables that ripened on the plant, collecting eggs that were laid that morning, or picking herbs that were growing just minutes before dinner.

I can't tell you that growing your own food will improve fertility because there simply isn't evidence to make that claim. What I can say is that it naturally encourages eating more whole foods, spending more time outdoors, moving your body, and reconnecting with where your food actually comes from.

As I was putting this episode together, one thing became clearer than anything else. There probably isn't one single cause behind the fertility challenges we're seeing around the world. It would actually make life much easier if there were. We could point to one chemical, one ingredient, one lifestyle habit, or one environmental exposure and say, "That's the problem."

But that's not what the published science suggests nor do our bodies operate like that I think.

Instead, it points toward a combination of factors that may all be interacting over the course of a lifetime. Nutrition, sleep, stress, age, environmental chemicals, physical activity, body weight, smoking, alcohol, air pollution, water quality, endocrine-disrupting chemicals, and countless other variables likely all contribute in ways we're still trying to understand.

If there's one thing I hope you take away from today's episode, it isn't fear. It's curiosity.

For me personally, this research has simply reinforced the direction I was already heading. Our bodies are remarkably resilient, but they're also deeply connected to the environments we create around them. Maybe the answer isn't chasing one miracle supplement or one viral health trend.

Maybe it's returning to some of the fundamentals that have supported human health for generations: nourishing food, quality sleep, regular movement, time outdoors, meaningful relationships, natural fibers, and being intentional about the choices we make every day. Until then, I think the best thing we can do is stay curious, keep asking thoughtful questions, and continue making informed decisions with the evidence we have today.

Thank you so much for listening to the Gubba Homestead Podcast. If you enjoyed today's episode, I'd love it if you shared it with someone who enjoys digging into these kinds of topics. Until next time, take care, keep learning, and I'll see you in the next episode.