Coffee and Microplastics: What the Latest Studies Actually Show

The most useful way to think about microplastics in coffee

Headlines about “microplastics in coffee” can make it sound as though researchers discovered that coffee beans themselves are full of plastic.

That is usually not what the study actually tested.

Researchers may instead be studying a plastic-containing drip bag, a disposable cup, a lid, a capsule, a water reservoir, or another part of the brewing process. Those are very different exposure questions.

For someone who drinks coffee every day, that distinction is useful because it points toward something you can actually control:

Instead of trying to make coffee “microplastic-free,” reduce unnecessary contact between very hot liquid and plastic-containing materials where it is easy to do so.

A 2025 study tested coffee people actually drink

One of the most useful recent studies was published in Science of the Total Environment in 2025. Rather than testing only one cup or brewing material under isolated laboratory conditions, researchers analyzed 155 measurements across common hot and cold beverages sold in the UK.^[1]

Their coffee samples included hot coffee purchased from major coffee-shop chains, coffee prepared in glass cups, coffee made using three domestic capsule machines, and iced coffee.

The researchers also compared hot and iced coffee purchased from the same coffee shop. Hot coffee averaged 16 particles per cup versus 11 in iced coffee, a statistically significant difference.^[1]

That does not mean temperature is the only variable. Water, manufacturing, packaging, equipment, transportation, and preparation can all contribute particles. But the researchers concluded that their findings were consistent with previous evidence that higher temperatures can increase particle release from food-contact materials.

So why did another coffee study find more than 10,000 particles?

This is where the research gets especially interesting.

A 2023 Food Chemistry study tested eight brands of disposable coffee drip bags made with materials including polyethylene, polypropylene, polyester, and rayon. Under one experimental condition, a single plastic-containing coffee bag steeped at 95°C for five minutes released more than 10,000 measured particles into a cup.^[2]

The researchers reported particles primarily in the 10–500 µm range and estimated that drinking three to four coffees prepared this way could correspond to roughly 50,000 measured particles per day under those experimental assumptions.^[2]

If someone drank one identically prepared cup every day, the study's experimental number would mathematically correspond to more than 3.6 million measured particles over a year.

But there is a major detail that deserves just as much attention as the headline number:

More than 80% of the particles identified in the drip-bag study were rayon.^[2]

The authors of the newer 2025 beverage study used a different approach. They focused on synthetic plastic polymers and excluded cellulose-based particles from their microplastic count.^[1]

Why can one study find 10 particles and another find 10,000?

Microplastic research is unusually sensitive to how a study is designed. Results can differ because researchers may:

• Measure different minimum particle sizes.
• Use different instruments to identify particles.
• Count different materials as “microplastics.”
• Use different temperatures and brewing times.
• Test water versus actual coffee.
• Test a laboratory soak versus a real-world beverage.
• Use different procedures to control for contamination during testing.

The U.S. Food and Drug Administration has similarly noted that differences in sampling, preparation, detection methods, and reporting make it difficult to directly compare many microplastic studies.^[4]

So the useful conclusion is not that your coffee definitely contains 10, 16, 10,000, or some other precise number of particles.

It is that plastic-containing materials can contribute particles to hot beverages, and the amount can vary considerably based on the material and conditions.

What about the disposable cup?

A paper coffee cup is not necessarily just paper.

Disposable paper cups generally need a barrier layer to prevent liquid from soaking through the paper. Many use a polymer coating, and lids may introduce another plastic material into direct contact with the drink.

In a study examining 90 batches of commercially available disposable cups, researchers tested polyethylene-coated paper cups, polypropylene cups, and polystyrene cups.^[3]

When filled with water at 95°C for 20 minutes, polyethylene-coated paper cups released between 675 and 5,984 measured microplastic particles per liter. The researchers also found that higher temperatures promoted particle release.^[3]

Again, that experiment should not be interpreted as a universal particle count for your morning latte. Twenty minutes of exposure to 95°C laboratory water is not identical to every real-world coffee order.

But it gives a practical reason to consider the cup itself, not just the coffee inside it.

Where do pods and coffee machines fit?

Coffee machines are more complicated because different models use different combinations of reservoirs, tubing, seals, heating systems, capsules, metals, and plastics.

That means it would be misleading to say that every pod machine or automatic coffee maker creates the same exposure.

Still, the 2025 study offers one interesting clue. The three domestic machines tested produced approximately 7, 10, and 17 synthetic microplastic particles per cup.^[1]

The machine with the highest measured concentration was also the oldest: approximately eight years old, with a PET plastic water tank. The researchers suggested that wear and material degradation could help explain the difference, although testing three machines is far too limited to establish a general rule about machine age.^[1]

In other words: do not throw away a functioning coffee maker because it contains plastic. But if you are already buying a new one, the materials used in the hot-water pathway are a reasonable feature to consider.

Why care about reducing exposure if we don't know the exact health risk?

There is an important distinction between saying “a cup of coffee containing microplastics causes disease” and saying “reducing unnecessary, repeated exposure is a reasonable precaution.”

The first statement is not supported by current evidence.

The second is increasingly understandable because researchers have detected micro- and nanoplastics in multiple human tissues and biological samples, and scientists are actively investigating their potential biological effects.

One of the most discussed human studies was published in The New England Journal of Medicine in 2024. Researchers examined carotid artery plaque removed from patients undergoing surgery. Polyethylene was detected in the plaques of 58.4% of the patients who completed follow-up.^[5]

Over an average follow-up of about 34 months, the composite outcome of heart attack, stroke, or death occurred in 20.0% of patients whose plaques contained detected micro- or nanoplastics versus 7.5% of patients without detected particles. After adjustment for several cardiovascular risk factors, the reported hazard ratio was 4.53.^[5]

This was an observational association, not evidence that microplastics caused those cardiovascular events. It also tells us nothing about whether drinking coffee from a particular cup changes cardiovascular risk.

What it does help explain is why researchers are paying increasing attention to human exposure in the first place.

If you drink coffee every day, here's what I'd actually change

1. Brew into glass, ceramic, or stainless steel when it is easy

A glass or stainless-steel French press, ceramic pour-over, glass Chemex-style brewer, or similar setup can reduce the number of disposable synthetic materials directly contacting hot water.

This does not make the coffee “microplastic-free.” Water, beans, filters, manufacturing, and the surrounding environment can all be additional sources. The goal is simply to remove an obvious and avoidable source of hot-plastic contact.

2. If you buy coffee every morning, a reusable cup is a higher-leverage change

An occasional takeaway coffee is not the point.

If you buy one every workday, however, the same material exposure occurs hundreds of times per year. Bringing a reusable glass, ceramic, or stainless-steel cup eliminates repeated use of one disposable food-contact material without changing the coffee you drink.

3. Avoid plastic-containing single-use drip bags when there is an easy alternative

Of the coffee formats studied so far, plastic-containing drip bags have produced one of the clearest direct experimental findings under hot-brewing conditions.^[2]

If you already have access to loose coffee and a traditional paper-filter, ceramic, glass, or stainless-steel brewing setup, this is an easy substitution.

4. Don't panic about the plastic inside your coffee machine

There is not enough product-specific evidence to declare every machine with a plastic reservoir or component problematic.

If your machine works well, there is no evidence here that you need to replace it. If you are buying a new machine anyway, you can consider how much plastic sits in the reservoir and hot-water pathway alongside price, performance, and durability.

5. Focus on repeated habits, not perfect avoidance

Exposure to microplastics is not limited to coffee. Particles have been reported in food, drinking water, household dust, air, and numerous consumer environments.^[4][6]

Trying to eliminate every possible exposure source is unrealistic.

A more practical approach is to identify high-frequency habits where an easy alternative removes unnecessary plastic contact.

Your daily coffee routine may be one of them.

A simple coffee material hierarchy

There has not been a comprehensive head-to-head trial proving that one brewing system universally produces the fewest microplastics. So this should be viewed as a materials-based framework, not a scientifically established risk ranking.

The bottom line

You do not need to give up coffee because of microplastics.

The science is not advanced enough to tell you that a Chemex contains exactly X fewer particles than a pod machine, or that drinking from a disposable cup creates a particular health risk.

But the research does give coffee drinkers a useful rule of thumb:

When very hot liquid does not need to touch plastic, it is reasonable to choose a material like glass, ceramic, or stainless steel instead.

That may mean brewing with a glass or ceramic setup at home, bringing a reusable cup to your local coffee shop, or choosing a traditional filter over a plastic-containing single-use drip bag.

These are small changes. They are also changes you can repeat hundreds of times per year without turning your morning coffee into something to worry about.

Where Sifts fits

Reducing unnecessary exposure is one side of the equation. But microplastic exposure does not come from coffee alone, and completely avoiding environmental exposure is not realistic.

Sifts is designed to support the body's natural handling of dietary particles during digestion. Its formula includes chitosan, a positively charged dietary fiber that can interact with particles in the gastrointestinal tract, alongside additional dietary fibers that support normal digestive elimination processes.*

Sifts is not a substitute for reducing avoidable plastic exposure. Think of it as part of a broader exposure-aware routine: reduce the sources you can control, without expecting yourself to live in a plastic-free world.

Frequently asked questions

Does this research mean I should stop drinking coffee?

No. None of the studies discussed here demonstrate that drinking coffee causes a health outcome because of microplastic exposure. The research identifies potential sources of particles during brewing, packaging, and serving.

Is pour-over coffee the best option?

There is not enough comparative research to declare one brewing method universally “best.” From a materials perspective, however, a glass or ceramic pour-over with a traditional filter can reduce obvious hot-plastic contact.

Is a paper coffee cup plastic-free?

Not necessarily. Many disposable paper cups use a polymer barrier coating to prevent liquid from soaking through the paper, and plastic lids can provide an additional source of contact.

Should I throw away my pod coffee machine?

No. Existing studies are far too limited to justify that recommendation. Different machines use different designs and materials. If you are replacing a machine anyway, materials in the reservoir and hot-water pathway are reasonable factors to consider.

Does switching to glass or stainless steel eliminate microplastic exposure?

No. Microplastics can enter food and drinks from multiple stages of production and from the broader environment. The goal is to reduce an unnecessary source of repeated exposure, not to achieve “zero microplastics.”

Why are microplastic counts so different between studies?

Researchers use different particle-size cutoffs, materials definitions, instruments, sample-preparation procedures, temperatures, exposure times, and contamination controls. A result from one study therefore cannot automatically be compared with a number from another study.

Sources

1. Al-Mansoori M, Harrad S, Abdallah MAE. “Synthetic microplastics in hot and cold beverages from the UK market: Comprehensive assessment of human exposure via total beverage intake.” Science of the Total Environment. 2025;996:180188. View study.
2. Wang HP, Huang XH, Chen JN, et al. “Pouring hot water through drip bags releases thousands of microplastics into coffee.” Food Chemistry. 2023;415:135717. View study.
3. Chen et al. “Release of microplastics from disposable cups in daily use.” Science of the Total Environment. 2023. View study.
4. U.S. Food and Drug Administration. “Microplastics and Nanoplastics in Foods.” View FDA resource.
5. Marfella R, Prattichizzo F, Sardu C, et al. “Microplastics and Nanoplastics in Atheromas and Cardiovascular Events.” New England Journal of Medicine. 2024;390:900-910. View study.
6. World Health Organization. Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health. 2022. View WHO report.