Mitigating Microplastic Risk

Will microplastics doom my longevity and healthspan?

TL;DR: New studies show that microplastics are incorporated into atherosclerotic plaque, brain tissue, prostate tumors, and more. This is worrisome for anyone interested in longevity or healthspan.

Are Microplastics a Problem?

Microplastics are tiny plastic particles that are ubiquitous in our environment today. To be honest, until a few years ago, I didn't worry much about eating a little plastic. I've seen what comes out of a dog when it eats a plastic dinosaur, so I assumed that plastic would just pass through the body. And big chunks of plastic probably just pass through.

When you read about plastic pollution in the ocean, the pictures usually show microplastics the size of grains of sand. Like this...

But microplastics, and what are now called nanoplastics, can be much smaller - microscopic instead of the size of a grain of sand. And these tiny bits in the μm range can easily be absorbed into the intestines and circulate through the bloodstream.

Let's take a look at the latest human studies, and then I'll explain why this is worrisome for health and longevity.

The latest on microplastics (in humans):

1. Heart health: A study published in May of 2024 looked at samples from “coronary and carotid arteries with atherosclerotic plaques, as well as the aorta without plaques.” The researchers found that all of the arteries sampled had microplastics in the atherosclerotic plaque. No microplastics were found in the aorta without plaques. They identified the plastic particles as consisting mainly of PET, PVC, polyamide-66, and polyethylene.

2. In males: An August 2024 study found that microplastics accumulate in the testes. The average was 328 µg/g in the testes in humans.

3. In the brain: A recent preprint study showed that microplastics readily accumulate in brain tissue. The researchers used brain samples from 2016 and from 2024. The brain samples contained more plastic in them than liver or kidney samples, showing a worrisome deposition in the brain. Plastic levels seem to be on the rise as well. There was an increase in the amount of plastic in the brain samples from 2024 compared to the 2016 samples. They found plastic at concentrations of 4800 mcg/g or almost 0.5% of the brain tissue being plastic.

4. In heart muscle tissue: A 2023 study found that microplastics were present in cardiac muscle tissue and in fat tissue surrounding the heart.

Healthspan and longevity: Making the connections

Let me pull together the threads here on why this is important for healthspan.

1. Cardiovascular health: The leading cause of death is heart disease. As a population, we spend billions on statins, hoping to reduce atherosclerotic plaque by lowering LDL cholesterol. However, research clearly indicates that atherosclerotic plaque forms when the inner layer of the artery is damaged. The Mayo Clinic explains that the damage to the artery that initiates atherosclerosis can be due to high blood pressure, smoking, high lipids, diabetes, etc. There’s been a push to lower lipids, smoking has decreased, and everyone is on either blood pressure or diabetes medicines — yet heart disease continues to dominate. What if a major new cause of atherosclerosis is simply a tiny, sharp plastic particle that damages the inner lining of the artery? The study showing microplastics in all atherosclerotic plaques is compelling.

2. In males: Prostate cancer is the second leading cause of cancer death in men. In a Sept. 2024 study, tumor samples from 22 prostate cancer patients showed pervasive microplastics.

3. Brain health: The amount of microplastics in human brain samples is astounding, and the accumulation appears to be accelerating compared to less than a decade ago. A recent cell study in neurons shows that nanoplastics significantly accelerate the formation of amyloid-beta plaques. There's also a likely link to APOE E4, lipid transport, atherosclerosis, and nanoplastics.[ref] The statistics on Alzheimer's are frightening - 13% of people aged 75-84 have Alzheimer's and 33% of people aged 85+ have it.[ref] If microplastics are accelerating Alzheimer's pathology, this is a real problem for our population.

4. What about the liver and lungs? A cell study in liver and lung cells shows that nanoplastics do not cause cell death. However, they do cause mitochondrial damage and reduced cellular energy production. Nanoplastic concentrations used in the study were comparable to environmental levels. Mitochondrial damage and reduced cellular energy may be easily overcome in youth, but this could be a serious problem in aging.

5. Immune system: Microplastics up to 10 μm are englufled by macrophages, which are one of our first lines of defense against pathogens and foreign particles. Studies show that polystyrene microplastics cause macrophages to give off a low-level inflammatory response. The key seems to be the amount of nanoplastics in our system. At low levels, macrophages can englulf the smallest particles without much of a systemic effect, but at higher levels, there is a more distinct change to the immune system.[ref] Chronic inflammation and changes to the immune system (e.g. inflammaging) is at the heart of the diseases of aging — and microplastics seem to exacerbate this.

How are we exposed to microplastics?

So where are all these microplastic particles coming from?

(This is a recap and update to what I put in an earlier substack article from about six months ago on microplastics.)

Sources of microplastics:

According to one review study, the biggest source of microplastics for humans is through food. Specifically — bottled water, seafood, sea salt, honey, beer, and “food components”. Behind food, air pollution is another source of microplastic exposure. Tires contain plastics, and every time we drive, we add a bit to the air.[ref]

Tea bags:
A study of tea bags showed that a single plastic tea bag (nylon and polyethylene terephthalate) “releases approximately 11.6 billion microplastics and 3.1 billion nanoplastics into a single cup of the beverage.” The study contends that the plastic particles released from the tea bag are orders of magnitude higher than plastics in other foods.[ref]
Solutions: Check the brand of tea you use to see if the bags contain nylon or PET. Consider loose tea in a tea strainer as an alternative.

Coffee in to-go cups:
Plastic cups are another big source of microplastics. Hot beverages in disposable cups have more plastic in them than cold beverages. Even paper coffee cups that are lined give off plastic. A study looking at the temperature of the liquid in disposable cups showed that hot beverages will contain more microplastics from the lining of the cup. Solutions: Bring your own mug if you regularly get coffee to go. If you normally get fountain drinks, stock up on inexpensive Yeti or Stanley knock-offs so that you always have one in your vehicle to use. If you have to use a plastic cup, rinsing the cup before using it cuts the microplastics in half.

Inhalable textile microplastics:
Synthetic textiles (e.g. polyester, nylon) shed fibers that accumulate indoors. A new preprint study found that nylon fibers negatively impact the lungs.
Solutions: Quite a few studies show that regularly vacuuming and dusting cuts down on BPA and other plasticizers in the body. Consider that what you put over your face — from face masks to fluffy scarves in the winter - is potentially going to be entering your lungs.

Plastic bottles:
While tap water can have some microplastics in it, apparently plastic bottled water is much worse. Beer seems to have a microplastic problem also.
Solution: Stop drinking anything bottled in plastic. Take your own metal or glass container along when you’re going to be out and about. If you have city water, consider a reverse osmosis filtration system for removing microplastics.

Breakdown of plastics in food packaging:
A big source of microplastics in our food is from packaging. As plastic wrappers are jostled, folded, stuffed, and pushed around, they break down just a little bit, leaving microplastics in contact with our food.[ref]
Solutions: Personally, I’m working towards more glass storage options for foods that regularly get taken in and out of the pantry. This can be as simple as using canning jars for storing things like baking ingredients, oatmeal, etc.

Getting rid of plastics in the body:

Melatonin at night:
A mouse study showed that melatonin reduced the amount of nanoplastics absorbed in the intestines and reduced the amount that reached the rest of the body.[ref] Prioritize melatonin production by blocking or avoiding blue light for two hours before bed. This likely ties into the gut barrier function, as well…

Gut healthy:
A 2022 study of orally administered polystyrene nanoplastics showed that they crossed the gut barrier, increased ROS (reactive oxygen species), increased liver lipid levels, and caused insulin resistance and elevated plasma glucose levels in the liver in mice.[ref]

”Leaky gut”, or the loosening of tight junctions between cells in the intestinal barrier, makes it more likely that small particles including microplastics will circulate in the bloodstream. The tight junctions between cells allow more to pass through into the portal vein when TNF-alpha or other inflammatory cytokines are high. This is a big problem in IBD (inflammatory bowel diseases), but could also be an issue for people who are genetically prone to elevated TNF levels.

Genetic Lifehacks article on TNF-alpha gene variants

Processed foods also often contain ‘nano’ additives such as nanoparticles of silver (E174), iron oxide (E172), silicon dioxide (E551), and titanium dioxide (E171). Research now points to these nanoparticle sized additives causing a low-level inflammatory response in the intestines, which in turn increases leaky gut and allows for nanoplastic particles to circulate in the body.[ref]

Titanium dioxide is used in a lot of processed foods and even dairy products to make them look brighter and fresher. US laws allow up to 1% titanium dioxide nanoparticles in food; the EU has now banned it as a food additive.

Emulsifiers in processed foods cause the intestinal mucosal barrier to thin out. For some, this can add to inflammation near the intestinal barrier to to the translocation of bacteria.

Genetic Lifehacks article on genetic variants that interact with emulsifiers

Solutions: Avoiding emulsifiers, such as carboxymethylcellulose or carigeenan, whenever possible and avoiding foods with nanoparticles, such as titanium dioxide, should help improve gut barrier function. Another new research study (in mice) showed that microplastic and nanoplastic particles by themselves increase oxidative stress in the gut, leading to leaky gut. However, adding antioxidants to the mix reduced the oxidative stress and mitigated the problems with intestinal barrier function.[ref]

Conclusion:

I don’t have all the answers here, but I am honestly concerned about the impact of nanoplastics on long term health. As the amount of plastic found in food, water, and dust continues to rise, gut health and quality sleep are a priority for me. Avoiding exposure whenever possible - without driving myself crazy - is also a goal. I’m going to continue making small changes to remove plastics from my environment.

Let me know in the comments if you have any brilliant advice on this topic. I’m looking for the relatively easy action that will give me the most bang for the buck.