The invisible ingredient

Making tea. Drizzling olive oil. Washing lettuce.

These small, ordinary rituals are how we nourish ourselves.

What many people have heard, but may not fully understand, is that alongside vitamins, minerals, and nutrients, another ingredient is often present. One we cannot see, taste, or smell. Tiny fragments of plastic are now routinely detected in food and water around the world.

This guide is not meant to alarm. It is meant to orient.

Its goal is to clarify what scientists mean when they talk about microplastics and nanoplastics, where these particles tend to show up in everyday foods, why reported numbers vary so widely, and what researchers currently know, and are still working to understand, about potential health implications.

First, the language matters

Before we talk about quantities or risks, it helps to slow down and define terms. Much of the confusion around plastic exposure comes from grouping very different particles under a single word.

We do this ourselves at times. In everyday conversation, microscopic synthetic particles, whether plastic or rubber, are often referred to broadly as "microplastics." The shorthand is convenient, and jumping straight into the jargon can otherwise become a barrier to understanding.

But here, a bit more precision matters. To make sense of the data, and the wide range of numbers that follow, we need to be more deliberate in how we use these terms.

Microplastics

Microplastics are plastic particles generally defined as being smaller than 5 millimeters in size. Some researchers use narrower cutoffs, focusing on particles below 1 millimeter or even smaller, which is one reason definitions can vary between studies.

At this scale, we are talking about anything smaller than a grain of rice, down to particles far thinner than a human hair, which is typically around 100 micrometers in diameter.

Microplastics come from two primary sources:

• Primary microplastics: Plastics that are intentionally manufactured at small sizes, such as industrial pellets or the microbeads once used in cosmetics and personal care products.
• Secondary microplastics: Fragments formed when larger plastic items break down over time. Heat, friction, sunlight, and everyday wear cause bottles, packaging, textiles, and household plastics to shed progressively smaller pieces. This is now the dominant source of microplastics found in food and drinking water.

Nanoplastics

Nanoplastics are smaller still. Typically defined as particles under 1 micrometer in diameter, measured in nanometers. To put that in perspective an individual human cell, something so small we can't really see them without a microscope, is often 10,000 to 20,000 nanometers in diameter. A typical bacteria cell is even smaller, often with a diameter of 500 to 2,000 nanometers in diameter. So most nanoplastics are much smaller than our own cells or even the tiny bacteria that live in our gut.

A simple rule of thumb helps explain why scientists pay such close attention to particles at this scale:

Same mass. Radically different particle count. And potentially very different impacts on biology.

Why size changes the conversation

Most large microplastics appear to pass through the digestive tract and are excreted. That does not make them irrelevant because they lodge into our gut lining and are found in our blood stream. They carry chemicals and cause oxidative and inflammatory damage.

Nanoplastics are different. Because of their small size, they may interact with our biology on a cellular level, more easily cross biological barriers, and carry surface chemistry that dramatically alters how they behave as compared to larger plastics.

This is why many researchers believe the number of particles may matter just as much as total mass, and why a food with "only" a small amount of plastic weight can still contain millions or billions of individual particles.

Where microplastics show up in food

When scientists began looking carefully, plastic contamination turned out to be far more widespread than expected. The ranges below reflect values reported in peer reviewed studies. They are not precise counts. They are snapshots from different regions, using different analytical methods. Some capable of detecting only microplastics, others able to capture nanoplastics as well.

Because of that, these figures are best understood as lower bounds, not true upper limits. Even so, clear patterns emerge.

Water and beverages

Plastic bottled water often contains anywhere from hundreds all the way to hundreds of thousands of particles per liter, spanning both microplastics and nanoplastics. Glass bottled water is not free of contamination either, with reports as high as thousands of particles per bottle. Most often microplastics shed from caps, seals, and bottling equipment. Beer, soft drinks, and tea tend to show lower but still measurable levels, largely reflecting the water and packaging used during production.

Dairy and animal products

Milk commonly contains thousands of particles per liter, much of it traced to plastic tubing, liners, and packaging used during milking and processing. Cheese often shows higher levels, particularly when it has prolonged contact with plastic films during aging and storage. Eggs and packaged poultry generally show lower counts, but contamination appears consistently, likely from feed, environmental exposure, and packaging.

Seafood

Shellfish and mollusks frequently contain between about 1 and 10 particles per gram, reflecting direct exposure to marine environments where plastics accumulate. Canned fish combines this environmental exposure with additional contributions from processing equipment and can linings.

Pantry staples

Sea salt typically contains more plastic than rock or lake salt because evaporation concentrates particles already present in seawater. Sugar, rice, honey, and edible oils also show contamination, largely introduced during processing, storage, and packaging rather than at the farm.

Fruits and vegetables

This is where reported numbers can become startling, and where particle size matters most. Many earlier food studies focused primarily on microplastics. But remember that a single microplastic particle can represent the same mass as roughly one billion nanoplastics.

With that in mind, some studies have reported thousands to tens of millions of particles in individual fruits and vegetables. These wide ranges reflect differences in soil contamination, irrigation water, root uptake, surface deposition, handling, packaging, and, critically, how small a particle the study was able to detect.

Why the numbers vary so much

You are not imagining it. The numbers vary. Often dramatically. And that variation is one of the most important parts of this story.

Measuring plastic particles in food is difficult. Researchers must first chemically digest away fats, proteins, and carbohydrates, then filter what remains, and finally sort through the residue to identify which particles are actually plastic.

Each step introduces tradeoffs.

Microscopy

• Pros: Visual, intuitive, good for counting larger particles
• Cons: Misses very small nanoplastics, can misidentify non plastic debris

Spectroscopy (FTIR, Raman)

• Pros: Confirms polymer identity
• Cons: Limited resolution for particles below a certain size

Electron Microscopy

• Pros: Extremely detailed images
• Cons: Expensive, slow, not scalable for large samples

Pyrolysis GC–MS/MS

• Pros: Highly sensitive and specific for identifying plastic polymers, even at very small sizes; measures total plastic mass rather than relying on visual identification
• Cons: Destroys the sample, does not provide particle counts or sizes, and cannot distinguish whether plastic mass comes from many tiny particles or fewer large ones; can confuse plastic-like biological materials as plastics

As methods improve and detection thresholds drop, reported particle counts rise. Not necessarily because food is suddenly becoming more contaminated, but because scientists are finally able to see what was always there. And over time, they will start to increase as we continue to make and discard more plastic into our world.

This is why older studies often report hundreds of particles, while newer ones report millions. They are often measuring entirely different size worlds.

In practice, no single method tells the whole story. Particle counts and mass measurements answer different questions, and both are needed to understand real world exposure.

What this might mean for health

This is where caution is essential.

Human data on long term dietary exposure is still emerging. What scientists can say with confidence today is limited, but growing. And the early data, in both lab, animal, and human systems is scary.

What We Know

• Humans are exposed through food, water, and air
• Most larger microplastics are likely excreted
• Smaller particles can interact more intimately with biological systems
• Plastics can carry additives and environmental chemicals on their surfaces

The "Trojan Horse" Concern

One of the leading hypotheses is not about plastic alone, but about what plastic carries. In this sense, the particle acts as a delivery vehicle. Micro and nanoplastics have been shown to bind and carry endocrine disrupting chemicals, persistent organic pollutants, heavy metals, and pathogenic bacteria.

What We Do Not Yet Know

Many of the most important questions are still open. Researchers are still working to understand the long-term effects of chronic, low-level exposure over decades, rather than short-term or high-dose scenarios. It remains unclear where meaningful biological thresholds lie. At what particle sizes, counts, or chemical loads exposure begins to matter in measurable ways.

Scientists are also investigating whether different polymer types behave differently in the body, and how particle size, from larger microplastics to nanoscale fragments, changes how these materials interact with cells and tissues. Just as importantly, individual factors such as age, gut health, diet, and microbiome composition are likely to shape how exposure affects different people.

The bigger picture

Plastic contamination in food is not a single problem with a single number. It is a spectrum shaped by particle size, chemistry, processing, packaging, and the limits of what our tools can currently detect.

A food with "low" microplastic mass may still contain billions of nanoplastics.

A food with "high" particle counts may simply have been measured more precisely.

Understanding this distinction helps explain why the conversation can feel confusing, and why oversimplified headlines often miss the point.

Micro- and nanoplastics are now an indisputable part of the modern food system. That reality is neither a moral failure nor a personal one. It is the result of decades of material choices made for convenience, durability, and cost.

This is the context in which Winnow exists. Not as a promise of avoidance, but as a response to reality. Complete elimination of exposure is not currently possible for most people. The more practical question becomes how the body handles what inevitably makes its way in, and how we can support natural elimination alongside broader efforts to reduce plastic use upstream.

The work ahead is not about fear.

It is about understanding scale, mechanism, and tradeoffs.

Clear language. Better measurement. Smarter materials.

And, over time, systems that put fewer invisible ingredients on our plates.

Understanding comes first.

Summary table

Item	Average levels	MPs	NPs	Suspected source
Edible oils	1,000 to 60,000 particles per liter	Yes	Yes	Contact with plastic during refining, storage, and processing equipment and ambient dust
Plastic bottled water	300 to 250,000 particles per liter	Yes	Yes	Shedding from bottle walls and caps, bottling line environments
Glass bottled water	1,000 to 10,000 particles per bottle	Yes	Yes	Abrasion and paint shedding from metal caps, airborne and process related contamination in bottling lines
White wine	1,500 to 4,500 particles per bottle	Yes	No	Glass bottle plus cap paint fragments, winery packaging films and caps
Beer, soft drinks, cold tea, energy drinks	Up to 30 particles per liter	Yes	No	Packaging (plastic liners, caps) and processing surfaces
Cow milk	2,000 to 10,000 particles per liter	Yes	No	Plastic tubing and liners in milking and processing, trays, and handling equipment
Fresh cheese	~1,000 particles per kilogram	Yes	No	Long contact with plastic wrap and processing
Ripened cheese	About 1,857 particles per kilogram	Yes	No	Extended maturation in contact with plastic films, other packaging plastics
Packaged poultry	4.0 to 20 particles per kilogram	Yes	No	Migration from expanded polystyrene trays and packaging
Eggs	~10 particles per egg	Yes	No	Environmental exposure of hens, feed, dust, and packaging
Canned fish	About 5 to 25 particles per tin	Yes	No	Marine debris plus contact with can coatings, sealing materials, and processing lines
Shellfish and mollusks	Often 0.1 to about 10 particles per gram	Yes	No	Direct uptake from marine environment, plus some post harvest contamination
Nori	About 1.8 particles per gram on average	Yes	No	Marine environment and handling during drying and cutting
Sea salt	50 to 800 particles per kilogram	Yes	No	Concentration of marine particles during evaporation, plus handling and packaging
Rock salt and lake salt	10 to 300 particles per kilogram	Yes	No	Environmental particles in source water and local dust; generally lower than sea salt
Granulated sugar	100 to 400 particles per kilogram	Yes	No	Ambient dust in processing plants, contact with plastic machinery and bags
Honey	25 to 150 particles per kilogram	Yes	No	Environmental dust settling in hives and processing spaces, plastic equipment parts
Uncooked rice	100 to 300 particles per kilogram	Yes	No	Environmental uptake in fields plus milling and packaging
Instant rice	500 to 2,000 particles per kilogram	Yes	No	Additional contamination during washing, drying, and intensive industrial processing
Apples	1,000 to 60,000,000 particles per apple	Yes	Yes	Root uptake from soil and irrigation water, plus handling and packaging. The huge spread reflects different methods and detection limits
Pears	750 to 45,000,000 particles per pear	Yes	Yes	Same general drivers as apples, including soil uptake and surface deposition
Carrots	180 to 10,000,000 particles per carrot	Yes	Yes	Uptake via roots from soil and irrigation, plus soil particles adhering to surface
Broccoli	1,500 to 60,000,000 particles per crown	Yes	Yes	Soil to plant transfer and deposition on complex leaf surfaces
Lettuce	500 to 40,000,000 particles per head	Yes	Yes	Uptake through roots and adherence on leaf surfaces
Tomatoes, cucumbers, onions, potatoes	5 to 25 particles per gram	Yes	No	Lower values reflecting different methods, size ranges analyzed, and geographic differences