Drink a cup of hot milk tea and eat hundreds of billions of microplastics! Microplastics that threaten health are everywhere, and we need to deal with them in this way

Have you noticed that there are more and more plastic products in our lives nowadays? It seems that everything we eat, use and wear cannot be separated from plastic packaging. But do you know that these plastics will break into very small particles during the degradation and production process, forming plastic particles with a diameter of less than 5 mm, called "microplastics". With the sharp increase in the use of plastics, microplastics have penetrated into our living environment and even entered the human body through the air, soil and water, posing a threat to our health.

In our daily lives, what are the scenarios where we come into close contact with microplastics?

(1) Microplastic particles are often found in daily necessities such as shampoo, shower gel and cosmetics , which are used for cleaning or polishing effects.

(2) Plastic packaging materials are also an important source of microplastics, especially food and beverage packaging.

(3) Tea bags . The packaging materials used for tea bags usually include synthetic fibers such as nylon, polyethylene, and polypropylene. These materials will release microplastic particles when soaked in hot water, which will then be ingested by the human body. This may interfere with the body's hormone balance and affect fat deposition and energy metabolism.

(4) Hot take-out drinks : A research team from the National Institute of Standards and Technology of the United States once found that if a cup of 100°C water was placed in an ordinary take-out coffee cup and allowed to stand for 20 minutes, trillions of plastic nanoparticles could be detected in each liter of water. In other words, drinking a 500 mL cup of hot coffee or hot milk tea may result in hundreds of billions of plastic nanoparticles entering the body.

(5) Microwave heating of plastic containers can cause plastic containers and reusable food bags to release more microplastics into food compared to other methods such as refrigeration or room temperature storage. Three minutes of microwave heating may cause food boxes to release 2 billion microplastic particles.

In recent years, medical and environmental science studies have found that microplastics accumulate in human organs. These tiny plastic particles enter the human body through various pathways, and microplastics of different sizes can be distributed in corresponding tissues, organs, and blood vessels.

Millimeter-sized microplastics are retained in blood vessels and tissues, while nanoscale ones can directly penetrate the biological membranes of cells and enter organelles and even smaller ultrastructures. Research on the impact of microplastics on human health is still ongoing, but some evidence has shown that microplastics may cause a series of health problems to the human body.

Do microplastics have an impact on patients with liver disease?

(1) Increase the risk of depression in patients with cirrhosis . An article published in the journal Environmental Pollution stated that patients with cirrhosis who ingest excessive amounts of microplastics are more likely to suffer from depression than ordinary people.

(2) For patients with viral infections, alcoholic liver disease, etc., the addition of microplastic factors will further change the metabolic processes of ammonia, glucose, and lactate, and aggravate neuroinflammation and damage to the blood-brain barrier.

85% of ammonia in the body enters the liver through the portal vein for metabolism and is excreted through the kidneys and intestines. Glutamine, one of the metabolites of ammonia, can induce hypertension in astrocytes, leading to cell swelling, neuronal damage, and brain edema. Therefore, metabolites produced by liver disease can act on the brain through the blood circulation, causing brain tissue damage.

(3) Aggravate cognitive dysfunction in metabolic-related fatty liver disease . In patients with metabolic-related fatty liver disease, excessive accumulation of microplastics aggravates lipid metabolism disorders, cognitive dysfunction and reduced brain volume.

(4) It may cause cholestasis. In recent years, the Center for Eco-Environmental Sciences of the Chinese Academy of Sciences has established a mouse model. Through continuous gavage for 30 days, it was found that microplastics can accumulate in liver tissue and cause damage. The study found that microplastics cause cholestasis in the liver by regulating the expression of genes related to bile acid synthesis and excretion.

Microplastics can also cause other harm to the body

(1) Respiratory tract: Microplastic particles in the air can enter the human body through breathing and accumulate in the lungs and respiratory tract, causing health problems related to the respiratory system.

(2) Digestive system: Microplastics in food and drinking water enter the human body through the digestive system and accumulate in the intestines. The liver and kidneys are the main detoxification and excretion organs of the human body. Microplastics may accumulate in these organs, affecting their normal functions.

(3) Cardiovascular: Some nano-sized microplastic particles can be spread throughout the body through blood circulation and accumulate on the inner walls of blood vessels, causing vascular inflammation and impaired endothelial function, which can aggravate the process of arteriosclerosis and the risk of heart disease, stroke, etc.

(4) Nervous system: Chemicals in microplastics can affect the growth and development of neurons, thereby interfering with their function.

(5) Endocrine system : Microplastics can simulate and interfere with the hormonal activities of the human endocrine system, such as simulating the activity of estrogen, affecting the development and function of the reproductive system, causing thyroid hormone imbalance and affecting thyroid function.

(6) Immune system: Microplastics can cause over-activation of the immune system through inflammatory response pathways, leading to allergic reactions, autoimmune diseases, etc. The chemicals in microplastics may also affect the function of immune cells and reduce the body's resistance to disease and infection.

In short, the reason why microplastics are a potential threat to human health is that although there are many studies on them in organisms at home and abroad and the degree of attention is increasing, there is still a lack of in-depth clinical data in the human body, especially on the intrinsic relationship between microplastics and human clinical diseases. Even if there are individual studies, they are only limited to the superficial description level of small samples. It is still unknown whether there is exact toxicity and long-term negative effects on the body.

Research data available to date indicate that the potential impact of microplastics on human health is extensive and significant, and is not limited to the liver. The negative effects on the cardiovascular and cerebrovascular, tumor, respiratory, nervous, endocrine metabolism and immune systems should not be underestimated.

To reduce the harm of microplastics, we can do this

(1) When drinking water: Use stainless steel or ceramic water cups instead of bottled water, and avoid using disposable plastic cups. If tap water is used, it is recommended to install a reverse osmosis filter for filtration.

(2) When eating: Reduce the consumption of the viscera of seafood, as this part contains higher levels of microplastics. Choose salt from non-marine sources and avoid canned soups and other foods that may contain higher levels of microplastics.

(3) When packing or heating: Use your own thermos cup instead of disposable paper or plastic cups. Avoid using plastic boxes or plastic bags to heat food in the microwave, especially acidic foods, which may release microplastic particles from plastic containers. Use reusable containers and packaging to reduce the use of disposable plastic products.

(4) When shopping: Choose personal care products that do not contain microplastics, such as natural skin care products and cosmetics. You can also pay attention to the composition of clothing and try to choose less synthetic fiber clothing.

(5) When cleaning: Keep the room ventilated, sweep and clean the room regularly, use a vacuum cleaner or air purifier with a HEPA filter, and clean with a wet mop and wet rag to reduce the flying of dust and microplastics in the air.

Microplastics are very close to us. They are already everywhere in our living environment and even exist in our bodies. However, they seem to be very far away from us because we often do not pay enough attention to them or even take them for granted. But in fact, the potential harm that microplastics bring to people's health should not be underestimated. I hope everyone will raise awareness, take action, reduce the use of plastic products, and protect themselves from the harm of microplastics to the greatest extent possible.

Author

Professor Cheng Shuquan

Guilin Third People's Hospital

Source: "Liver Doctor" 2025 Issue 1