You’ve probably heard microplastics are everywhere — in our brains, in our hearts, in possibly every single man on earth’s testicles. Studies published in major medical journals have reported that microplastics are plentiful in seemingly every inch of the human body and they have attracted widespread media attention. Most of us have gotten the message loud and clear: These manmade materials can’t be good for us, and ungodly amounts of them are already lurking inside our bodies.
Settled science, right? Well, hold on a second.
New reporting from our partners at the Guardian has called some of that widely publicized science into question. Covering a range of studies, the report cites both interviews with leading subject matter experts and scholarly reviews to challenge this narrative of human bodies teeming with deadly molecules. The critics ask: How confident can we really be about how much of this stuff is inside us, given the challenges in measuring anything at the molecular level?
These studies were primarily focused on the prevalence of microplastics in samples taken from real people; other research has focused on the ways plastics harm health or the population-level health effects as plastics have become so woven into our lives. The type of research in question attempts to discern exactly how much these substances have penetrated people’s bodies, which was what led to those eye-grabbing headlines.
But, according to the Guardian’s reporting, some researchers are calling foul on a number of methodological problems with these studies.
On the study that inspired headlines of brains soaked in microplastics, researchers who were not involved noted that fatty cells in the brain have a history of throwing up false positives for polyethylene, a microplastic of concern. They also flagged the possibility that microplastics from the lab environment could have contaminated the samples, a concern raised about other studies covered by the Guardian and an unavoidable challenge for this kind of research; microplastics are literally everywhere.
And as a result, the study could be overstating, perhaps dramatically so, how many microplastics are actually present in people’s brains.
Other studies had their own flaws, but the criticisms tell the same story: The research that led many of us to believe our bodies are swimming in microplastics may not have been as definitive as it seemed.
If your head is spinning, nobody could blame you. The fact is, this is something that happens a lot: New science gets overconfidently reported either by the researchers themselves or by journalists, driving people and policymakers to react even when the underlying evidence is more uncertain than the popular narrative suggests.
There is an important lesson in this story, not only for how we think about these microplastics but for how we should internalize scientific findings that have major implications for our health.
This is how science is supposed to work
Let’s start here: The media bears some blame for the microplastics mania. We tend to sensationalize and oversimplify findings because we’re writing for a lay audience and we need to capture people’s interest. Take the Guardian story itself: This debate between academics has been playing out in public in the Nature Medicine journal since November, though this week’s story presented itself as “a bombshell.”
No one is accusing researchers of malpractice here. This is purely a question of methodology and our ability to measure the human body at the molecular level.
I spoke with co-authors of the brain study, and they pointed out that they actually did flag in their paper the possibility that fatty molecules could confound their research. But they argued the size of the effect they tracked over time was too significant to be explained by that factor alone. The news stories covering the study often didn’t mention that nuance.
And to be fair, microplastics research is a fairly young space. This is inherently difficult and scientists should be striving to fine-tune their methods so they can report findings with more confidence.
That’s how the scientific method is supposed to work: You collect data, you report it, you get critiqued, you keep working to duplicate and build upon your findings.
“Nobody's getting it perfect,” Matthew Campen, a biochemist at the University of New Mexico and co-author of the brain study, told me. “But when you start combining the best practices, all of a sudden, I think in a year, maybe two, we're going to have this unassailable approach, and we're going to have really accurate and consistent data.”
This is a broader phenomenon across medical science and diagnostics: We have developed shockingly precise tools for measuring things in the human body, but our ability to understand what we are seeing is still catching up
That’s okay. As we gather more information and improve our technology, we should be able to get better at interpreting the signals. But it takes time.
A smarter way to think about microplastics and your health
We should be clear about something: These critiques are largely aimed at studies that have measured the prevalence of microplastics in our bodies, taking (in the case of the brain study) samples collected during autopsies and scouring them to come up with a measure of how many microplastics are present. But this is just one lane of microplastics research, and the broader field is focused on piecing together how microplastics might actually impact our health.
Experimental research has shown over and over again that the chemicals present in plastics are toxic to humans. Population cohort studies have found that exposure to, for example, phthalate is associated with a higher risk of death from any cause, but especially cardiovascular disease.
“What I tell people is plastic is toxic, so try to avoid it where you can,” said Renee Sharp, an environmental health expert at the Natural Resource Defense Council. “That can be challenging because it's everywhere, and it's even in places that we don't even necessarily want it. But do what you can.”
With that in mind, we don’t have to overreact to every new scientific finding or media fixation. Remember the black spatula freakout? A popular article published in the Atlantic suggested that your plastic cookware is probably leaching nanoparticles into your food. Ack! I went out and bought some nylon cookware, just to be safe. You had writers like Annie Lowrey at the Atlantic trying to eliminate plastic entirely from their lives (before giving up because it proved too hard). Then, a counter-take argued the Atlantic’s story had overinterpreted the evidence.
Don’t subject yourself to this cycle. Plastics are everywhere, and they aren’t good for your health. But let’s also put the risk in a proper context.
Campen, the co-author of the brain study, put it to me like this: “Let’s not panic.” While there is understandable trepidation about all the artificial substances in our modern world, in the context of history, we seem to be doing ok: people are living longer than ever. Chronic diseases are becoming more, not less, manageable. There are particular concerns associated with microplastics that we are still trying to understand, such as early-onset cancer, but we are also living in a golden age of medicine and longevity — one made possible, in part, by plastics in medical care. (There is, at the same time, a growing conversation about how to decrease plastic use in hospitals and clinics — our relationship to this stuff is complicated.)
And that means we shouldn’t just stop worrying about microplastics either. “Don’t overreact” cuts both ways. One way to interpret the Guardian story is: If we don’t have as much plastic inside of us as we thought, maybe we can do more to mitigate our plastic risk before it’s too late. It’s tempting to get fatalistic about our exposure when it seemed like they were really everywhere and already inside you. Don’t be.
Instead, as you start hearing about new science like this, look for “low pain” interventions, something you can do to try to reduce risk based on our limited knowledge, but without totally upending your life, given the inherent uncertainty. The NRDC has a list of practical tips: Drink tap water, not bottled water, when possible; don’t microwave any food in plastic; when you can, opt for bamboo cutting boards or glass mixing bowls instead of plastic ones. You can check if any of your cosmetics include ingredients like polyethylene or nylon-12: if so, consider something else.
And whenever the next popular health panic starts, remember: We are learning new things all the time, and some of those things could dramatically reshape how we think about our health. This is a good thing. But good science does take time. Do what you can, don’t freak out at every new headline, and let the researchers keep working.
