Microplastics and Your Health

Six critical questions about microplastics: answered

Sep 30, 2024

An image of microplastics in the heart from the New England Journal of Medicine study that sounded the alarm about microplastics and health.

Post summary

Microplastics may be the next big health threat.
New research is showing microplastics are linked to an increased risk of heart disease, brain diseases, liver issues, and more.
But the research is new and and questions exist about whether microplastics are causing the issues or merely a symptom of other problems.
We’re diving into six topics you need to know about microplastics.

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The post

Microplastics are everywhere. I mean this both figuratively and literally.

Figuratively, more and more reports are coming out every day about the possible health threats of microplastics.

The research on microplastics has been building for years. But in March of this year, a New England Journal of Medicine article dropped a bomb.

The study discovered that 58 percent of patients undergoing a carotid endarterectomy procedure—surgically removing heart plaque—had microplastics in their heart plaque. Importantly, the presence of microplastics in the heart was linked to a 4.5-fold increase in death, heart attack, or stroke.

This study was a sort of alarm bell that put scientists and the general public on notice.

In a literal sense, microplastics are, indeed, everywhere—in our food, air, and environment.

“Microplastics” has become a catch-all term for tiny plastic particles smaller than 5 millimeters wide. And their pervasiveness may be contributing to the most common modern health maladies.

Today, we’re diving into microplastics and answering:

How pervasive they are.
Where they come from.
How they enter our bodies.
How they impact our health.
Whether you can totally avoid microplastics.
What we do and don’t know about microplastics (Two Percent Sanity Sauce).

How pervasive are microplastics?

Very. One study put it succinctly:

Microplastic particles can be found everywhere in the environment. Indeed, they can be found in the air, drinking water, food we eat and even in lakes, rivers and seas; they are all around us.

Scientists have discovered them in snow in the Arctic, deep in the ocean, on pristine beaches in the middle of the Pacific, and high on mountaintops of the Alps.

You may have heard that the average person consumes a credit-card’s worth of microplastics a week, or five grams of microplastics weekly.

That stat seemed like complete bullshit when I first encountered it. And, luckily, scientists have proven it is.

A more reasonable study found we probably ingest around 4 micrograms a week (one thousand micrograms equates to one gram.) The scientist explained, “(This) means that a human eats a credit card worth of microplastics not every week but every 23,000 years.”

But who cares what the number is? If that New England Journal of Medicine study tells us anything, less is probably better.

Where do microplastics come from?

Humans ingest them through a handful of paths. The top sources include:

Single-use plastic bottles (e.g., bottled water)
Single-use aluminum cans (e.g., beer)
Air
Tap water
Seafood

But they’re also in table sugar and salt, and, to some degree or another, foods packaged in plastic—from kid’s cereal to chicken breasts shrink-wrapped in Styrofoam trays.

They’re also pervasive in the world around us.

When we think of plastic pollution, we tend to think of disposable plastic water bottles or grocery bags.

But 80 percent of microplastic pollution in the environment comes from synthetic fabrics (much of what we wear is plastic), tires, and city dust.

How do they enter our bodies?

One study found they enter us in many ways.

It explained: “We understand very well now that microplastics can enter our body via different routes, comprising inhalation, ingestion, and (skin) exposure. Out of these, ingestion is the most common pathway for microplastic exposure in humans.”

We eat or drink them in bottled drinks ranging from water to milk and foods packaged in plastic.
We breathe them in through the air. They’re often so small they become airborne.
They come in contact with our skin. For example, one study found they can enter our bodies through our skin via chemical plastics manufacturers use for different processes.

How do microplastics impact health?

This is a new topic in research. We still have a lot to learn, but the early work suggests the following:

Heart

If how you’ll die is a gamble, then heart disease is like blackjack. It offers the best odds in the house.

The average person has a fifty-fifty shot at dying of heart disease. And new studies suggest the more microplastics you have jammed into your ticker, the better your odds of death by heart disease.

Recall the New England Journal of Medicine study that kicked off all this new-found awareness of microplastics. It discovered the presence of microplastics in the heart was linked to a 4.5-fold increase in death, heart attack, or stroke.

Brain

Most research on brains and microplastics occurs in animals. These studies suggest that plastics cross into the brain and that the brain can accumulate microplastics. That could lead to neuro-inflammation, which is a risk factor for brain diseases like Alzheimer’s, dementia, and Parkinson’s.

One study did look at humans. It analyzed 91 human brain samples and showed that microplastic accumulated about 10 to 20 times more in the brain than in other organs.

Those researchers also examined 12 brains from people who’d died with dementia. The patients had about ten times more plastics in their brains compared to people who didn’t have the neurodegenerative disease.

Liver

One small study compared the load of microplastics in the livers of people who were healthy to the amount in the livers of people who had liver cirrhosis. The scientists wrote:

“(We) found six different microplastic polymers in the liver of individuals with liver cirrhosis, but not in those without underlying liver disease.”

The scientists noted that they don’t know if microplastics caused the issue or whether unhealthy livers are simply unable to get rid of microplastics.

Reproductive health

Evidence in animals shows microplastics may impact babies in the womb. One study concluded, “An increasing body of evidence suggests that in utero exposure to microplastics not only adversely affects fetal and neonatal body weight but also compromises fetal organ development.”

We know microplastics appear in human placenta and that women exposed to more chemicals in microplastics produce fewer eggs.

But, the scientists wrote, “What is less clear is … the extent to which these exposures influence fertility, fetal development and subsequent offspring health.”

Meanwhile, men with higher levels of chemicals in microplastics showed “decreased sperm concentration and decreased total sperm count.” They also registered lower testosterone.

Cancer

One review tackled the topic of microplastics and cancer.

It suggests microplastics may trigger uncontrolled cell growth, “leading to various cancers affecting the lungs, blood, breasts, prostate, and ovaries. Additionally, such contamination can potentially affect sub-cellular signaling and injure multiple organs,” according to the scientists.

But, the scientists also wrote, “Due to the need for extensive, interdisciplinary, and long-term interdisciplinary research, the precise impact of microplastics on human health remains largely unknown.”

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Two Percent Sanity Sauce

Please take a deep breath before you sell everything plastic in your home on Facebook Marketplace and move to a wooden yurt off the grid. Here’s some Two Percent Sanity Sauce1:

People today live longer than ever, yet we’re using more and more plastic. Indeed, some of the generations exposed to the worst plastic pollution are right now living into their 90s.
This may also be a chicken and egg phenomenon. That is to say, having a high level of microplastics could just suggest that you have other factors impacting your risk of disease. For example:
- You may eat a diet far heavier in packaged foods, which are often ultraprocessed. Excess ultraprocessed foods are linked to many bad health outcomes.
- You may live near more pollution in general, especially air pollution.
- You may have a job that exposes you to more pollution. For example, given that we know tires are a key source of microplastics, it follows that working on, say, a road crew would likely expose you to more microplastics.

Is there a way to totally avoid microplastics?

No. Our world runs on plastic. The material is efficient and ubiquitous.

Wherever you’re reading this, stop and look around you. You can probably find tens, if not hundreds, of individual pieces of plastic. To take examples of plastic items that are in my direct field of vision right now:

Computer keys.
Computer screen.
Pen.
Cords leading to computer.
My water bottle straw.
Cell phone case.

FFS, even my home’s air filter—the thing supposedly filtering these things out—is made of plastic fibers. Plastic filtering plastic—plastics all the way down.

It’s impossible to entire get away from plastic. Plastic is so ubiquitous, that even our best efforts can’t get us totally away from it.

Consider the manufacture of milk. Even if you buy organic milk distributed in a glass bottle, the device that attaches to udders when milking the cow is plastic, as are the lines the milk runs through. And the milk passes through plastic in other parts of the manufacturing process.

How to avoid microplastics

Even though we’re still learning about the impacts of microplastics, the research on their possible adverse health effects means that it’s probably worth avoiding microplastics where it’s easy.

On Wednesday, we’ll cover some painless ways to take in less microplastics.

Have fun, don’t die,

-Michael