Microplastics in Food: What a Major Review Found in Everyday Staples, and What It Couldn't Measure

Bottom line

A review published in the Journal of Hazardous Materials pulled together 193 studies of microplastics in food and drink. In the authors' model, grains, fruits and vegetables made up 99.5% of the microplastic particles people are estimated to eat. Everything else, seafood included, shared the remaining half a percent.

That doesn't tell us whether plant foods are safe or unsafe, and it isn't a measurement of anyone's diet. It is a model that combined uneven results from many labs with average figures for how much of each food people eat. The headline share rests on just four studies of fruits and vegetables and six of grains.

The estimate also stops at 1 micrometer. Nanoplastics, the smallest particles and the ones I'm most concerned about, aren't in the numbers at all. The authors left them out because there isn't yet enough comparable data to count them in food.

In this article

Why I went looking at food

Most of my research this year has circled one problem. The particles I worry about most are the ones nobody can reliably measure yet. In January I wrote about why nanoplastic ingestion is so hard to measure, and then about why no single lab test tells the whole story.

Since then I've spent much of the year trying to get drinking water tested for nanoplastics, including sessions in a lab at UC San Diego. The smallest particles have been the hardest part every time.

So when I came across a large review of microplastics in food, I wanted to know two things. Which foods does the evidence say we get most of our microplastics from? And can it tell us anything about nanoplastics?

One detail made me read it closely. The lead author, Maria Hayder, also led the 2025 study combining AF4 and Py-GC-MS that I cited in my lab testing post. That method separates particles by size and then identifies the plastic. So this review comes from a group working on exactly the measurement problem I keep running into.

The question I set out to answer:

What does a 2026 review of 193 studies say about which foods supply most of the microplastics we eat, and how much can it tell us about nanoplastics?

What the researchers did

Researchers at the University of Amsterdam and Utrecht University gathered published studies that counted microplastics in food and drink, up to August 2025. That came to 193 papers counting particles, plus 12 that measured plastic by weight. The review in the Journal of Hazardous Materials is open access, so you can read the full paper for free.

They sorted the data into 13 categories: fish, crustaceans, mollusks, grains, meat, fruits and vegetables, tap water, bottled water, milk, salt, beer, other beverages, and sugar and honey. They left out studies of animal parts we don't eat, like a fish's gut, and experiments on plastic shedding from packaging.

The hard part is that labs see different size ranges. The paper notes that FTIR, a common method, can't identify particles below about 10 to 20 micrometers, while Raman can reach about 1 micrometer. To put every study on the same footing, the authors assumed smaller particles become more numerous in a predictable way, a pattern called a power law. They used it to estimate each study's count across one common range, 1 to 5,000 micrometers.

They then multiplied those concentrations by global average consumption figures and divided by the body weight of a 70-kilogram adult. That makes this a model, not a measurement. Here is what went into it and what didn't.

What they found: everyday foods dominate the estimate

The authors start with a point about research itself. Seafood has been studied far more than anything else, and they write that the number of papers does not reflect dietary habits. They suggest that's because filter feeders like mussels were expected to collect the most plastic.

When the authors ran the numbers, fruits and vegetables had the highest median estimated intake, at 406 particles per kilogram of body weight per day. Grains were the other big contributor. In the paper's conclusions, those two groups together make up 99.5% of the total estimated intake.

Part of the reason is volume. Grains, fruits and vegetables show up at almost every meal, so even a modest concentration adds up. The paper's highlights also say other foods were more contaminated than seafood. With so few plant food studies behind that, I hold it loosely.

Across all 13 categories, the median total came to 721 particles per kilogram of body weight per day. The paper puts that at about 51,000 particles a day for an average adult.

I wouldn't hold onto that number either. The full range of estimates ran from 0.0077 to 380 million particles per kilogram per day. The highest is roughly 49 billion times the lowest. A spread that wide tells me the data can't yet say how many microplastics a person actually eats.

Why I read 99.5% as a direction, not a number

The more time I spent in the paper, the less weight I put on the exact figure. The headline rests on a small number of studies, and the testing method changed the answer.

Four studies is very little to carry most of a global estimate. The authors found the fruit and vegetable results fell into two separate groups, and said the split clearly comes from the different analytical techniques used. With only four studies, the median lands somewhere between two very different answers.

Counting particles by eye under a microscope cut both ways in this review. Visual methods gave far higher counts for fruits and vegetables, but lower counts for beer, salt and beverages. Natural material can be mistaken for plastic, and small or clear particles can be missed.

The size extrapolation adds another layer. For a study whose instrument stopped at 10 or 20 micrometers, every particle between 1 micrometer and that cutoff is an estimate, not a count. The authors caution that the size pattern they assumed might not hold for every food.

Then there's study quality. The authors scored each paper on 10 criteria, including clean air conditions, negative controls and positive controls. The average was 11.4 out of 20, and positive controls, which check that a method actually recovers plastic, were the weakest area.

Dropping the lowest-scoring papers raised the total estimate by 16%. The authors note this may mean their quality criteria don't reliably reflect the quality of the results.

None of this makes the review wrong, and the authors are upfront about all of it. It means I read the 99.5% as a strong signal about where research should look, not a precise share of anyone's exposure.

Counting particles isn't the same as weighing plastic

Most of the studies counted particles. Only 12 measured plastic by weight, and that smaller set told a different story. By weight, seafood came out on top, mollusks and crustaceans in particular, with grains third. The median came to about 70 micrograms per kilogram of body weight per day.

The authors call that ranking very preliminary, since it rests on so few papers. The two measures also answer different questions. A huge number of tiny particles can weigh less than a handful of larger ones.

Weighing doesn't solve the nanoplastic problem either. A method like pyrolysis GC-MS can tell you how much of a polymer is in a sample, but not whether it came from a few larger particles or a great many tiny ones. I went into that limit in my post on nanoplastic lab testing.

The missing size range: nanoplastics

This is the part I came for, and it's the part the review couldn't count. Every headline number covers particles from 1 to 5,000 micrometers. Below 1 micrometer, or 1,000 nanometers, particles are usually called nanoplastics, though research groups define the cutoff differently.

The authors didn't ignore them. They wrote that there is a scarcity of studies quantifying nanoplastics in food, so they left them out of the estimates. They also wrote that nanoplastic research is moving fast and they expect that to change.

They point to the early work that does exist. Some studies have found nanoplastics in real products, including commercial sea salt, PET-bottled drinking water and beverages sold in Vietnam. Others were method studies, such as one on leafy green vegetables, where food was deliberately spiked with tiny plastic particles to see if they could be found again.

That second kind of study matters, but it answers a different question. Spiking a sample with known plastic tests whether a method works. It doesn't tell you how much plastic was in the food to begin with.

Why nanoplastics are so hard to measure in food

The tools that work for larger microplastics run out of reach below a micrometer. This is how the main methods compare, drawing on the review and on my earlier lab testing research.

Food is also a messy sample. The review notes that leftover food material may have interfered with measurements even after digestion. Contamination from air, clothing and lab equipment matters more the smaller the particles you're hunting, which is why the authors scored studies on clean air and negative controls.

This gap shows up in my own earlier research too. A 2024 study of bottled water counted about 240,000 plastic particles per liter, and about 90% were smaller than 1 micrometer. I covered it in my post on how microplastics and nanoplastics enter your body. That is exactly the size range this review had to leave out.

Unmeasured doesn't mean absent

I can't conclude from this review that nanoplastics are rare in food. I also can't say how many there are, whether they outnumber larger particles, or how much they would add to the totals. The honest answer is that the nanoplastic share of what we eat is still unquantified.

That matters because size seems to change how particles behave in the body. In my January post on nanoplastic ingestion, the research I reviewed suggested particles below about 1 micrometer are absorbed at higher rates than larger ones. Most of that evidence comes from animal studies, and this review didn't look at absorption at all.

Which plastics showed up

The most commonly reported plastics were polyethylene, used in bags and films, PET, used in bottles and polyester, and polypropylene, used in containers and packaging. The authors say the mix roughly follows how much of each plastic the world produces.

Finding a polymer doesn't tell you where it came from. PET in a food sample could come from a bottle, but also from processing equipment, clothing fibers or the lab itself.

What this review doesn't tell us

This was an exposure review, not a health study. These are the questions it leaves open:

• How much any one person eats. Diets, food sources, preparation and local environments all vary.
• How many nanoplastics are in food. They weren't estimated.
• Where the plastic got in. The review didn't separate the environment from processing, packaging, transport or kitchen prep.
• How much the body absorbs. Swallowing a particle isn't the same as absorbing it into blood or tissue.
• What level causes harm. The review set no safe or unsafe threshold for microplastics or nanoplastics.
• Which actions reduce exposure. Washing, peeling, cooking and storage weren't tested.

Those gaps don't make the review less useful. They mark the edge of what it can support.

Where this leaves me

Here is where I've landed, and how sure I am of each part.

The direction is real, even if the number isn't. In this model, the foods we eat every day, not seafood, supply almost all the estimated microplastic particles. I think that's a useful correction to where research has been looking.

The 99.5% is fragile. It rests on four studies of fruits and vegetables and six of grains, and the testing method changed the result. I expect the exact figure to move as better studies come in.

There's no personal number here. The estimates span more than ten orders of magnitude, and much of each count is extrapolated below what the original instruments could see. I won't be quoting a daily particle count from this review.

The smallest particles are still missing. Nanoplastics aren't in the estimates at all, because the methods aren't ready yet. Not being measured doesn't mean they aren't there. The size range I'm most concerned about is the one this review couldn't count.

It doesn't answer the health question. The review didn't look at absorption, harm or what reduces exposure, and it makes no dietary recommendation.

My own read, which is not proven. Most of the particles in this estimate are 1 micrometer or larger. My January research suggested particles in that range mostly pass through the body rather than being absorbed, though that evidence comes largely from animal studies and human data is thin.

That's why this review doesn't change my focus on nanoplastics. If anything, it confirms that the part of the problem I care most about is still the part nobody can count.

A note on these conclusions

The conclusions in this post are mine. They reflect how I read the research as of November 2026 and how I think about the problem. I'm not a scientist, and this isn't scientific or medical advice.

I'm sharing my reasoning to help you form your own conclusions, not to tell you what's right for you. Where I've drawn a conclusion the research doesn't prove, I've said so. Every source is linked below, so you can check them and judge for yourself.

References

1. Hayder, M., Laan, M. M., & van Wezel, A. P. (2026). Exposure to microplastics from food: Comparative analysis of food types and quantification techniques. Journal of Hazardous Materials, 501, 140657. Read the paper (DOI) · Free full text, Utrecht University · PubMed record
2. Hayder, M., Veclin, C., Ahern, A., Chojnacka, A., Roex, E., Meier, F., Gruter, G. J. M., van Wezel, A. P., & Astefanei, A. (2025). Integrating AF4 and Py-GC-MS for combined size-resolved polymer-compositional analysis of nanoplastics with application to wastewater. Analytical Chemistry, 97(28), 15216–15224. Read the study
3. Ruan, X., et al. (2024). Nanoplastics detected in commercial sea salt. Environmental Science & Technology, 58, 9091–9101. Read the study
4. Zhang, J., et al. (2023). Identification of poly(ethylene terephthalate) nanoplastics in commercially bottled drinking water using surface-enhanced Raman spectroscopy. Environmental Science & Technology, 57, 8365–8372. Read the study
5. Qian, N., Gao, X., Lang, X., Deng, H., Bratu, T. M., Chen, Q., Stapleton, P., Yan, B., & Min, W. (2024). Rapid single-particle chemical imaging of nanoplastics by SRS microscopy. Proceedings of the National Academy of Sciences, 121(3), e2300582121. Read the study
6. Stanley, R. (2026). The Nanoplastic Ingestion Problem: Why We Can't Measure It. Plastic Free Living.
7. Stanley, R. (2026). Lab Testing for Nanoplastics: Why No Single Test Tells the Whole Story. Plastic Free Living.
8. Stanley, R. (2026). How Microplastics and Nanoplastics Enter Your Body: Daily Exposure. Plastic Free Living.
9. Stanley, R. (2026). Our Water Testing Journey at UCSD. Plastic Free Living.