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Key Takeaways

• Microplastics can disrupt metabolism and liver function, increasing the risk of insulin resistance and type 2 diabetes.
• Plastic particles also harm gut health, contributing to further inflammation and an increased risk of disease.
• Simple actions, such as avoiding heated plastic containers and opting for whole foods, can help reduce exposure and support detoxification.

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Microplastics are small plastic pieces measuring less than 5 millimeters in length (approximately the size of a pencil eraser). In contrast, nanoplastics are even smaller and are not visible to the naked eye.¹��

Microplastics and nanoplastics are present in all aspects of the food supply, ranging from the containers that hold your food at the store to the ocean water where fish grow until harvest.¹��

Evidence suggests that these small pieces of plastic are entering the food supply and ultimately ending up in our bodies, with research indicating their potential to disrupt metabolic processes and pose health risks.^2,3

This article examines the pervasive presence of microplastics in the food supply and our bodies, exploring how these tiny plastic particles can disrupt glucose metabolism, impair liver function, and contribute to conditions such as insulin resistance and type 2 diabetes.��

Understanding Microplastics and Their Presence in Food

Microplastics and nanoplastics (or micro-nano-plastics, MNP) enter the food chain through various pathways. Let’s start with their origin.

Plastics were developed after the Industrial Revolution in the early 1900s and possess many useful characteristics, including lightweight, moldable, low production cost, ease of manufacture, and transport. They are used in various applications, such as food packaging, building materials, electronics, medical equipment, beauty products, single-use containers, and clothing.³��

Over time, and with the increased use of plastic, they have accumulated due to limited disposal options, leading to habitat and water pollution. As these plastics break down, they produce smaller plastic fragments, known as micro- and nano-plastics, which are no longer visible.³

MNP are found in oceans, rivers, groundwater, sediment, soil, sewage, and even the air. Plastic does not biodegrade well; it simply breaks down into smaller pieces, eventually reaching a point where it can enter biological membranes in your body.³��

The human body is exposed to MNP through three primary routes: inhalation, ingestion, and skin contact. Most MNPs can cross the body's safety barriers, including the lungs, gut, and skin.³��

In humans, microplastics have been detected in blood, urine, saliva, feces, and breast milk. Research has shown that they can accumulate in various organ systems, including the lungs, colon, and spleen.³��

This raises the question of what health effects these micro- and nano-plastics have on humans, and whether they are toxic.

How Microplastics Disrupt Metabolic Health

Due to its relatively recent existence and the newer understanding of how plastic doesn’t break down, there is limited human research on its impact on metabolic diseases, such as heart disease and insulin resistance, which is a risk factor for type 2 diabetes.��

However, research on mice indicates that a common microplastic, polystyrene, affects blood sugar and insulin response. Mice were fed with a normal-balanced chow diet or a high-fat diet. Mice fed either diet exhibited insulin resistance after exposure to polystyrene.⁴��

Additionally, microplastics caused gut inflammation, unfavorable gut bacteria, and the accumulation of plastic in the livers, kidneys, and blood vessels of the mice. Researchers hypothesize that changes in gut bacteria and their accumulation in tissues contribute to the stimulation of inflammation and insulin resistance.⁴

Heart health and metabolic health often go hand in hand. New evidence suggests that plastic and its chemical additives (DEHP) contribute to cardiovascular disease (CVD) through increased oxidative stress and metabolic dysfunction.⁵��

In 2018, an estimated 356,238 deaths worldwide were attributed to DEHP exposure, representing 13% of all CVD in adults aged 55-64. Most (98%) of the DEHP exposure was related to microplastics.⁵��

Finally, a higher prevalence of cardiometabolic disease in people living in coastal areas. A study from the Journal of the American Heart Association found that residents of 152 coastal counties with high levels of marine microplastic pollution had an 18% higher risk of type 2 diabetes, 7% higher risk of coronary artery disease, and a 9% higher risk of stroke compared to those in coastal areas with low levels of microplastic pollution.⁶��

While microplastics are ubiquitous, individuals living near bodies of water contaminated with microplastics are disproportionately affected.⁶��

Further research is needed to understand the full extent of microplastics' impact on the body; however, it's clear that the abundance of microplastics is detrimental to both human and animal health.��

The Impact on Liver Function and Gut Health

An article mentioned earlier highlighted the effect microplastics have on the gut health of mice. Mice exposed to microplastics exhibited gut inflammation, poor gut microbiota, and a buildup of microplastics in the liver.⁴

New research in mice suggests that microplastics may exacerbate fatty liver disease, particularly when combined with a high-fat diet. In a 2025 study, mice were fed either a normal or high-fat diet, with or without daily exposure to common microplastics. After 14 weeks, researchers assessed gut and liver health.⁷��

Both microplastics and a high-fat diet increased gut inflammation, oxidative stress, and damage to the gut barrier. Mice also exhibited fat build-up in the liver, a symptom of metabolic dysfunction-associated steatotic liver disease (MASLD). When mice were given both microplastics and a high-fat diet, liver damage was even more severe.⁷��

Even after stopping microplastic exposure and a high-fat diet for two weeks, the gut and liver didn’t return to normal, suggesting lasting harm or the need for longer healing time.⁷��

Human research has found that high exposure to microplastics increases the presence of harmful bacteria and reduces the abundance of beneficial gut bacteria.²��

In mice, microplastics are linked to gut inflammation, weakened gut lining, poor gut health, increased inflammation, liver damage (inflammation and scarring), may even harm bone marrow, and changes in brain function (memory and cognition).²��

Inflammation, oxidative stress, and the presence of microplastics can weaken the cells that line the gut, making it “leaky” or more susceptible to bacteria and toxins that can leak from the intestines into the bloodstream.²��

As the gut becomes less protective, the liver is also facing the same injury. The liver filters most everything that enters the body, and excess stress can lead to inflammation and tissue damage, ultimately resulting in reduced function over time.²��

Long-Term Health Implications

Animal studies and population data suggest that prolonged exposure to microplastics may contribute to various chronic health issues.

Poor gut health as a whole is linked to weight gain, obesity, insulin resistance, and chronic low-grade inflammation, all of which are risk factors for type 2 diabetes.⁸��

Microplastics further exacerbate poor gut health, inflammation, and insulin resistance, thereby perpetuating a situation that predisposes you to chronic health conditions.^2,4,7

The earlier discussion of increased cardiometabolic conditions observed in humans and animals exposed to high levels of microplastics supports the negative impact on the heart and blood vessels.^5,6

Poor cognitive health is also associated with high exposure to microplastics. Research in vitro (in the laboratory) and on animals reveals that high exposure to micro- and nano-plastics may lead to increased inflammation in the brain, as well as damage to brain cells, which may impact memory, mood, and cognition.²��

Lastly, hormonal imbalances and fertility may be affected by microplastics, which can act as endocrine disruptors, altering hormones such as estrogen, testosterone, and thyroid, as well as the systems they regulate. Animal and in vitro research also suggest that microplastics may affect or damage fertility and alter fetal growth and organ development.²��

While research is still ongoing, the long-term effects of high microplastic exposure are not favorable.

6 Strategies to Reduce Microplastic Exposure

Practical lifestyle strategies can help you minimize exposure to microplastics and aid in their removal from your body.��

Here are some practical tips for reducing ingestion and combating the effects of exposure:

1. Choose fresh, unprocessed foods like fruits, vegetables, beans, nuts, eggs, and sustainably sourced fish, chicken, and beef. Whole foods contain antioxidants and nutrients that help your body fight inflammation and support overall health.
2. Avoid using plastic packaging whenever possible. Plastic is often unavoidable when purchasing food, but consider using glass or cardboard containers instead. You cannot avoid plastic altogether, but you can reduce your exposure.
3. Use glass, cast-iron, or stainless-steel containers to cook, heat, and store hot food. Heat releases more microplastics than cold temperatures. Researchers have found that it would take six months of plastic storage containers at room or cold temperatures to release the same amount of microplastics as three minutes of microwaving a plastic food container.⁹
4. Filtering drinking water that may be contaminated with microplastics. Reverse osmosis or ultrafiltration systems help to remove microplastics. Some carbon filters can also remove them.��
5. Avoid bottled beverages. Bottled water contains more microplastics than tap water. Carbonated drinks in plastic bottles release even more microplastics.¹⁰
6. Increase your intake of fiber-rich foods to promote motility and facilitate regular bowel movements. Your body will excrete microplastics through its usual elimination route. However, if you are not regular, this is a great way to speed up the removal of microplastics and enjoy better overall health.��

The Bottom Line

Microplastics are a hidden and silent threat to metabolic health, with recent research linking them to insulin resistance, liver dysfunction, and chronic inflammation. While most research is conducted on animals or in vitro, this preliminary evidence suggests that exposure can disrupt gut health, metabolic function, liver health, and other risk factors for chronic diseases.��

To protect your health, prioritize whole foods rich in fiber, avoid heating or cooking in plastic containers, and opt for filtered water and drinks instead of bottled water or soda.��

Learn More With 91�������’ Expert Advice

Considering where your food comes from, how it is cooked, and how it is packaged can also impact your metabolic and gut health.

A continuous glucose monitor (CGM) enables you to track your blood sugar levels, helping you understand how diet, food choices, hormones, and exercise impact your body and blood sugar levels. These positive changes can help you improve your overall health.

Learn more on 91�������’ blog, written by health and nutrition experts.��