Microplastics Could Be Adding to Your Risk of Fatty Liver Disease

One of the most widely used plastics in the world – found in food packaging, plastic wrapping, storage tubs and takeaway cups – could partly influence the risk of fatty liver disease.

The condition in its modern form was first documented in 1980. Yet doctors have understood since the 19th century that fat accumulating in the liver is in some way connected with diet, well before formal research got under way.

Now, a mouse study indicates that modern food conveniences may be compounding the issue.

Fatty liver disease: symptoms and risk factors

People are often unaware that they have non-alcoholic fatty liver disease until it is found by chance during a scan for an unrelated problem.

For those who do have symptoms, these can include tiredness, generally feeling unwell and discomfort beneath the ribs on the right-hand side.

Fat can accumulate in liver cells and, without treatment, may eventually cause inflammation, followed by fibrosis – a build-up of scar tissue – and even cirrhosis, or severe liver damage.

Stages of fatty liver disease (now known as metabolic dysfunction–associated steatotic liver disease) progress from healthy liver tissue to steatosis (fat accumulation), inflammation, fibrosis, and cirrhosis. (National Institute of Diabetes and Digestive and Kidney Diseases/NIH)

The likelihood of fatty liver disease is higher in people carrying extra weight, particularly around the waist.

Further risk factors are raised levels of blood fats – LDL cholesterol or triglycerides – type 2 diabetes, prediabetes, and high blood pressure.

Each of these factors is linked to diet and metabolism. However, the new mouse research points to a potentially overlooked dietary consideration: exposure to microplastics, particularly polyethylene.

Polyethylene is central to convenient food packaging: it holds takeaway meals, wraps leftover food in cling film, and prevents a single-use cup from disintegrating in your hand.

Compared with many other polymers, however, polyethylene has generally been regarded as less worrying.

"No studies have really looked into polyethylene's effect on liver health, and it's the most widely produced plastic," explains molecular pharmacologist Adi Joshi of Texas A&M University.

"What we now know is that these microplastics, especially polyethylene, affect our liver's natural defense and repair mechanisms."

Polyethylene microplastics in the mouse study

The work by Joshi and colleagues, published in Science Advances, involved experiments in mice. More research is therefore needed before it can be established whether polyethylene produces the same, or similar, effects in human livers.

The mouse sample was also fairly small, although the effects observed were nevertheless concerning.

The researchers divided twenty male mice into four groups.

A schematic overview of the experimental design showing the different treatment groups and analysis techniques. (Jung et al., Science Advances, 2026)

Groups 1 and 2 received standard laboratory mouse chow. Groups 3 and 4 were given a diet high in fat, sugar and cholesterol, known to induce metabolic dysfunction-associated steatohepatitis, or MASH – the medical name for this type of fatty liver disease.

Mice in groups 2 and 4 also received a daily water dose containing two milligrams of polyethylene particles measuring between 10 and 150 nanometres in diameter.

The treatments lasted eight weeks. The mice were then euthanised, and researchers collected their blood serum and livers for detailed examination.

The findings indicate that microscopic polyethylene may induce signs of fatty liver disease even when mice are fed a standard diet.

As anticipated, the two groups fed the MASH diet recorded substantially higher scores for markers of fatty liver disease than the groups receiving standard chow.

Yet adding microplastics seemed to worsen the condition irrespective of diet, including in mice on a comparatively healthy diet.

Both groups whose diets contained microplastics had greater levels of ALT – an enzyme that indicates poor liver health – and liver triglycerides than animals eating the equivalent diet without polyethylene.

Liver-cell inflammation and ballooning, along with steatosis, or fat accumulation in the liver, showed the same pattern.

How polyethylene may affect the liver

Molecular and histopathological effects of polyethylene microplastics in mouse liver with or without a high-fat diet. (CD = control diet, Veh = vehicle [water with no microplastics], MD = MASH diet, PE = polyethylene). (Jung et al., Science Advances, 2026)

Joshi and colleagues used spatial transcriptomics on the mouse-liver samples to examine genetic readouts for proteins made in response to microplastic exposure.

Genes that encode the proteins PPAR-alpha, which controls liver-fat production, and Annexin A2, which helps repair liver tissue, were both operating at elevated levels in livers affected by microplastics.

Larger studies are clearly necessary. Based on the evidence available so far, though, polyethylene microplastics and an unhealthy diet may each contribute to the development of fatty liver disease – particularly when they occur together, as they frequently do.

Related: A Common Cholesterol Treatment May Also Remove PFAS And Microplastics From Blood

"Those who have a more Western-style diet, including foods like burgers and sodas, may have a greater chance of progressing to fatty liver disease if they are also exposed to polyethylene," Joshi says.

The research was published in Science Advances.

This article was fact-checked by Rachel Garner and edited by Clare Watson. Although we take pride in our process, we are only human. If you notice an error, please let us know.