Are you getting tired of reading about plastic? I wouldn’t blame you. We are getting exhausted writing about the perils of plastic. That said, almost every week there is new news about problems with plastic. This week there are two unpleasant developments. The first follows on previous research that suggests many of us have plastic in our brains. The new research published in JAMA Network Open (Sept. 16, 2024) is titled “Microplastics in the Olfactory Bulb of the Human Brain.” You will be surprised to learn how that likely happens. In addition, there is an article in the Journal of Exposure Science & Environmental Epidemiology, Sept. 17, 2024. It is titled “Evidence for widespread human exposure to food contact chemicals.” We hope it will help us rethink how we our food is packaged and stored.
Plastic in Our Brains: What Is the Olfactory Bulb?
Scientists have just reported that they have found microplastic shards of plastic in human olfactory bulbs. Before we tell you why that’s important, let’s take a crash course in neurophysiology and neuroanatomy. First, how do you smell stuff? We all take smell for granted…until we lose this critical sense. Just ask COVID patients who lost their sense of smell. Losing this important sense can be devastating. For one thing, food no longer tastes the same. Some people are plagued by horrible odors that make their life miserable.
Here’s the quick anatomy lesson. You have millions of olfactory epithelium cells deep in your nasal cavity. Receptor cells there transmit nerve impulses to the olfactory bulb. This brain structure is just above the nasal cavity and below the frontal cortex. Think of the olfactory bulb as a relay station. It receives messages from the olfactory nerves in the nose and sends them up to the olfactory cortex (piriform and periamygdaloid cortex), the entorhinal cortex and the anterior olfactory nucleus and the olfactory tubercle.
OK…anatomy lesson over. Relax. The bottom line is that the nerve cells in the nose connect to the relay station in the brain called the olfactory bulb.
Why does all this matter? Because the research published in JAMA Network Open (Sept. 16, 2024) revealed microplastic shards of plastic in the olfactory bulbs of 8 out of 15 autopsy cases. That’s 50%.
The plastic included:
- Polypropylene
- Polyamide
- Nylon
- polyethylene vinyl acetate
- Polyethylene
- Perlon polyamide
- Wool-polypropylene
These microplastic particles “exhibited indications of weathering.” In other words, they were not “pristine.”
How Do We Get Plastic in Our Brains?
The location of the plastic particles suggests that tiny bits of plastic could get into the brain if they were in the air these people were breathing. The fact that they were weathered suggests that they were from old plastic.
The researchers note that nanoplastics, particles that are even smaller and harder to detect than microplastics, might be present in greater numbers. Neuroscientists do not know yet whether the accumulation of plastic in the brain could affect cognitive function, but they worry about the potential for the chemicals in plastic to disrupt brain health.
The authors of this study state:
“In previous epidemiological studies, exposure to PM2.5 [fine particulate matter] has been associated with neurological and psychiatric adverse outcomes, such as dementia. Some neurodegenerative diseases, such as Parkinson disease, seem to have a connection with nasal abnormalities as initial symptoms. In experimental studies, both exposures to PM2.5 and MPs [microplastics] have [been] shown to cause several neurotoxic effects, including disturbances on the brain development.”
The authors interpret their research to mean:
“The presence of microplastics in the human olfactory bulb suggests the olfactory pathway as a potential entry route for microplastics into the brain, highlighting the need for further research on their neurotoxic effects and implications for human health.”
Bottom Line on Plastic in Our Brains:
One likely source of plastic in our brains that we have not considered until now is the air we breathe. We may all be breathing in microplastic particles without realizing it.
Plastic Is Everywhere!
It’s found in nearly all packaging of consumer goods. If you want to buy juice, the likelihood is it will be in plastic. Water? Right again! Almost all water bottles are made of plastic.
The study just published in the Journal of Exposure Science & Environmental Epidemiology, Sept. 17, 2024 reveals that there are thousands of food contact chemicals (FCCs). These are chemicals that are used:
“…to store, process, package, and serve foodstuffs.”
The results of the research in the authors’ own words:
“For 25% of the known FCCs (3601), we found evidence for their presence in humans. This includes 194 FCCs from human biomonitoring programs, with 80 of these having hazard properties of high concern. Some of these are considered worrisome because they are endocrine dirsuptors.
We take food packaging for granted, whether it’s shrink wrapped meat or poultry, salad dressing in a plastic bottle or salsa in a plastic tub. The lead author of this study recounted an anecdote in which she was offered a meal on a flight. The salad dressing was served in a small plastic container. Remembering that plastic compounds leach more easily into fats or acidic foods, she decided to forego dressing on her salad. When you look at the photo at the top of the page you will see that a lot of oils are now sold in plastic containers. That’s also true of vinegar.
Where Does Plastic End Up After We Throw It Away?
There are massive quantities of plastic in the ocean and in landfills. Researchers report that it’s in us as well. If you are a man, there is a good chance your have microplastics in your testicles (Toxicological Sciences, May 15, 2024). That’s in addition to microscopic particles of plastic in your arteries (New England Journal of Medicine, March 7, 2024).
Plastic in Our Bodies!
Researchers have been studying the effects of phthalates, bisphenols and other plasticizers for years. These chemicals are key elements in the production of a variety of plastic products. That’s because they add flexibility and strength.
Such chemicals have been found in water bottles, baby bottles, pacifiers, sippy cups, toys and the lining of cans. We now know that these chemicals have also found their way into us. You can learn about the biological effects of plasticizers and PFAS compounds by listening to our podcast at this link.
Now scientists are beginning to look for actual particles of plastic in tissue. These microplastics are turning up in some worrisome places. A few weeks ago researchers reported that arterial plaque often contained nanoparticles of plastic. More about that momentarily.
Plastic Particles in Testes:
First, though, scientists at the University of New Mexico report that microplastics have been found in human and canine testicular tissues (Toxicological Sciences, May 15, 2024). Dogs that had higher levels of polyvinyl chloride plastic bits had lower sperm counts.
The authors note that endocrine disrupting chemicals like PVC can disrupt spermatogenesis. With plastic ubiquitous in our environment, the next question is whether men, like dogs, have begun to experience reduced sperm counts.
The authors conclude:
“These findings highlight the pervasive presence of microplastics in the male reproductive system in both canine and human testes, with potential consequences on male fertility.”
A group of experts recently published a paper in the journal Human Reproduction Open (April 12, 2024) titled:
“Current global status of male reproductive health”
The implications of their overview:
“Poor MRH [male reproductive health] is a global issue that suffers from low awareness among the public, patients, and healthcare professionals.”
How much of poor male reproductive health is due to plastic and plasticizers is anyone’s guess. So far, researchers have been slow to consider this potential problem. Have you read The Handmaid’s Tale?
More About Plastic In Our Brains!
In recent months, scientists have reported finding micro particles of plastic in human organs such as testicles, hearts, livers and lungs. Now, scientists report that autopsies show micro- and nanoparticles of plastic in our brains (Research Square, May 6, 2024). Even worse, these tiny shards of plastic are increasing over time.
The researchers compared autopsy data gathered in 2016 to tissue samples gathered in 2024. Levels of micro and nanoplastics are now roughly 50% higher than they were eight years ago. The researchers note that the amount of plastic particles in brain samples was 7 to 30 times higher than that seen in livers or kidneys. They conclude that plastic appears to accumulate selectively in brain tissue, which could be worrisome as global rates of dementia continue to rise. Please note that this research has not been peer-reviewed; the publication is a pre-print.
Bits of Plastic in Arteries Too:
Microplastic and Nanoplastic in Carotid Arteries:
When most people think about clogged arteries, they imagine the heart. But many individuals also develop clogged carotid arteries in the neck. When blood flow is blocked in the carotids it can lead to TIAs (transient ischemic strokes) that are sometimes referred to as mini strokes. If a piece of plaque breaks loose from a clogged carotid artery, it can cause a full-blown stroke.
Symptoms may include temporary paralysis or weakness on one side of the body. Numbness in an arm or leg is another potential symptom. Vision loss or speech impairment is another tipoff that something is wrong.
When doctors detect clogged carotid arteries (stenosis) they sometimes perform what is called an endarterectomy. This removes plaque from the carotid arteries and is designed to improve blood flow to the brain and reduce the risk of a stroke.
A landmark study published in the New England Journal of Medicine (March 7, 2024) is titled:
“Microplastics and Nanoplastics in Atheromas and Cardiovascular Events”
That is doctor talk for plastic in your arteries and the risk for vascular nastiness.
Researchers Removed Plaque from Clogged Arteries:
In the new study researchers introduced their study this way:
“Microplastics and nanoplastics (MNPs) are emerging as a potential risk factor for cardiovascular disease in preclinical studies. Direct evidence that this risk extends to humans is lacking.”
These investigators attempted to provide direct evidence of a risk resulting from plastic in your arteries.
Here is what they did:
“We performed a prospective, multicenter, observational study in which patients were assigned to groups (one group with plaque in which MNPs were detected and one group with plaque in which MNPs were not detected) after enrollment.”
To put it simply, over 200 patients had their nasty plaque removed. Roughly 60% had tiny nano or microplastic in their diseased arteries. What kind of plastic? The kind of plastic particles that are ubiquitous in our environment: polyethylene and polyvinyl chloride (PVC).
The more plastic in your arteries, the greater your risk of inflammation and bad outcomes. That’s what these researchers found.
Here, in their own scientific words, is what they found:
“Among patients with asymptomatic high-grade (>70%) carotid artery stenosis [blockage] who were undergoing carotid endarterectomy, those with evidence of MNPs [microplastics and nanoplastics] within the carotid plaque had a greater incidence of a composite of myocardial infarction [heart attack], stroke, or death from any cause than patients who did not have evidence of MNPs within the atheroma.”
This research is so provocative we hope that it stimulates a lot of interventional cardiologists to look at the plaque in coronary arteries. If there are MNPs in carotid arteries that contribute to heart attacks and strokes, why wouldn’t there be particles of plastic in heart arteries as well?
So…how do you end up with plastic in your arteries?
Plastic in Bottled Water:
Bottled water has become very popular. That’s because some people believe it is healthier and others find it more convenient. A significant number of Americans worry about the quality of their tap water and think that bottled water is better. Americans buy over 40 billion 1-liter bottles of water each year, and most of those are made of plastic. But is water in plastic bottles actually safer than tap water?
A study published in the Proceedings of the National Academy of Sciences reports that a typical 1-liter bottle of water contains about 240,000 particles of nanoplastics (PNAS, Jan. 8, 2024). Nanoplastics are even smaller than microplastics, less than a micron wide. For comparison, a human hair is about 80 microns across.
The researchers believe that these teensy plastic bits are coming from the bottle itself as well as the reverse osmosis membrane filter used to get rid of other contaminants. Unfortunately, they do not have information on the potential health consequences of consuming nanoplastics. However, it seems very likely that nanoplastic particles in bottled water are a source of plastic in your body.
Plastic Is NOT Impermeable!
Most people think that plastic is inert. It seems solid enough. But we began to suspect something was up with plastic almost 50 years ago. When we were in graduate school at the University of Michigan, we met a woman who had worked in a communications job for the plastics industry. She warned us that the industry she had worked for was paying careful attention to questions about the leaching of chemicals out of plastic containers.
This was just a few years after Dustin Hoffman heard the word plastic in the movie The Graduate (in 1967).
The Graduate “One Word: Plastics”
Mr. McGuire pulls Dustin Hoffman aside
“I just want to say one word to you. Just One Word
“Yes Sir
“Are you listening?
“Yes I am
“Plastics
“Exactly how do you mean?
“There’s a great future in plastics. Think about it. Will you think about it?
“Yes I will
“Enough said. That’s a deal.”
If you want to see the actual scene from this memorable movie, here is a link.
Is There a Problem with Plastic?
Plastics have indeed come to dominate our lives. We take plastic for granted and assume it is safe. And yet we have learned that plastics contain chemicals that get into our bodies. Phthalates are found in most soft plastic. These chemicals make plastic pliable. Phthalates are also called plasticizers.
Decades ago we became aware of the possible toxicity of the phthalates in plastic intravenous containers.
An article in Drug Intelligence & Clinical Pharmacy offered this early warning (Sept. 1982):
“Many containers for intravenous solutions are made with plasticized polyvinyl chloride, the common form of which is di-2-ethylhexylphthalate (DEHP). Extraction of DEHP into blood and plasma stored in such plastic containers can occur, and harmful effects of DEHP in the human body consequently have been suggested. Reports on toxicity of DEHP in animals during pregnancy and the developmental period are critically reviewed.”
Endocrine Disruptors:
Many ingredients in plastic, like bisphenol A (BPA) have been dubbed endocrine disruptors. That means they may act like hormones in the body, especially estrogen. Perhaps you remember the baby bottle furor from a few years ago.
The New York Times summed it up nicely (July 17, 2012).
“The Food and Drug Administration said Tuesday that baby bottles and children’s drinking cups could no longer contain bisphenol A, or BPA, an estrogen-mimicking industrial chemical used in some plastic bottles and food packaging…”The F.D.A. declared BPA safe in 2008, but began expressing concerns about possible health risks in 2010.”
An article in Scientific American titled “BPA-Free Plastic Containers May Be Just as Hazardous” raised new concerns about plastic (Aug. 11, 2014).
More recently, an article in National Geographic’s Science & Innovation publication (Sept. 13, 2018) offered additional concern: “Why ‘BPA Free’ May Not Mean A Plastic Product is Safe.”
Is There Plastic in Your Body?
Almost assuredly there are phthalates circulating in your blood stream.
A large study by the CDC concluded:
“CDC researchers found measurable levels of many phthalate metabolites in the general population. This finding indicates that phthalate exposure is widespread in the U.S. population.”
But what about actual plastic in your body? A small study that included eight participants from Japan, Russia and Europe found tiny particles of plastic in their stool (United European Gastroenterology annual meeting, Vienna, Austria, Oct. 23, 2018). Nine different types of plastic were detected out of the ten the researchers were looking for. Polypropylene and polyethylene terephthalate (PET) were the most common.
What Does It Mean to Have Plastic in Your Body?
No one knows the implications of these findings. How widespread is plastic contamination of the human digestive tract? Scientists suspect that perhaps half the people on earth carry microplastic around in their guts, but this has not been proven.
They also do not know whether exactly how microplastic particles might alter immune responses or affect hormonal systems. The research published in the New England Journal of Medicine on March 7, 2024 suggests that many of us have microplastics and nanoplastics in our carotid arteries. I bet that a lot of people also have MNPs in their coronary arteries. What is clear is that we cannot continue to add plastic to our environment and expect to remain unaffected.
Learn More:
If you want to learn more about these issues, we interviewed an expert on How Do Endocrine Disruptors Affect Your Health? You can stream the audio for free at this link. You can also listen to a recent interview with the People’s Pharmacy pediatrician, Dr. Alan Greene. He will tell you how to protect our children from the perils of plastic at this link. Share your thoughts in the comment section below. If you think this in-depth article is important, please share it with friends and family.
