Microplastics: a new danger to our health

So, how much plastic did you eat today? Isn’t that a pointless question, because normal people don’t eat plastic? Unfortunately, no. Microplastics and nanoplastics are all around us, so we don’t just eat and drink them, we breathe them in. And it turns out that this can cause us a number of problems. Is there anything we can do to protect ourselves?

Plastics production is growing at a steep pace – for example, in 2019, around 368 million tonnes of plastics were produced globally. In addition, an estimated 10 tonnes of plastic enters the oceans every year. Until recently, we thought that the problem with plastic waste was that it was non-biodegradable – that if we dumped a nickel in nature, it would remain there unchanged for thousands of years. Unfortunately, it turns out that this is not the case.

The action of various physical, chemical and biological agents causes plastics to gradually break down into miniature particles. If these particles are between 0.1 µm and 5 mm in size, we call them microplastics; particles smaller than 0.1 µm are called nanoplastics. These not only contaminate nature, but also enter our bodies.

How big a problem is this? Honestly – no one knows. What is certain is that these particles circulate in our bodies in significant quantities and settle in our tissues. And we also know that when micro- and nano-plastics are exposed to laboratory animals, it causes a range of health problems. It is therefore likely that the gradual contamination of the planet with plastics will also have a negative impact on human health.

So let’s summarise what we know so far about the miniature plastic hazard and how we can reduce its negative impact on our bodies.

They’re everywhere. Even in us.

Microplastics and nanoplastics are everywhere – they have even been discovered in the ice in the Arctic and Antarctic. They are mostly found in aquatic environments, but from there they enter the food chain. They can also spread through flying insects whose larvae live in aquatic environments – typically mosquitoes, for example – and thus contaminate other environments. They accumulate in the soil, for example, where they not only degrade its quality and productivity, but also penetrate plants, including agricultural crops.

Other microplastics and nanoplastics are then introduced from food that has been contaminated by them during production or kitchen handling – for example, bottled water contains much more of them than water from natural sources, which means that it has been contaminated during bottling and storage. Plastic kitchen equipment can also be a source, as can clothing made from synthetic materials.

When the researchers looked at human stool from this perspective, they found between 1 and 36 microplastic particles in each gram. An estimated 8 % of the ingested particles either remain in the intestines or even enter the bloodstream, affecting tissues throughout the body – in this case, in particular, nanoplastics, which, due to their small size, are even able to penetrate the brain. In addition, micro- and nanoplastics do not only enter our bodies through food, but can also be inhaled and penetrate the skin.

Why can they harm us?

Microplastics, and especially nanoplastics, are not only a threat to marine ecosystems, but have also been shown to have a negative impact on humans. First and foremost, they can damage our intestines, because it is the digestive tract that receives the most of them. However, the negative changes are also felt throughout the body. First and foremost, inflammatory processes increase in intensity, but many bad things also happen directly at the cellular level: for example, molecular signalling pathways are disrupted, but also negative epigenetic changes, i.e. changes in the activity of a number of important genes in the DNA. This can lead, for example, to certain metabolic disorders.

Chemicals released from plastic particles can also be a problem. Many of these are added to plastics during manufacture to improve their properties or appearance. A typical example is cadmium, a heavy toxic metal whose compounds are used in plastics as stabilisers and pigments. For example, when cadmium-containing microplastics were exposed to fruit flies, the flies suffered extensive damage to their intestines and disrupted behaviour and movement patterns. The cause here was, among other things, the negative epigenetic effects of cadmium, which led to the switching off of some important genes in the flies’ DNA.

Another problematic substance that is added to plastics and can be released from fragments is bisphenol A, which acts mainly as a hormone disruptor but also has negative epigenetic effects. In addition, microplastics and nanoplastics can absorb other substances from the environment – heavy metals, antibiotics and even pathogenic micro-organisms that form a biofilm on the surface of the particles. These can then contaminate drinking water, fish, etc.

Changes throughout the body

As we have already mentioned, the negative effects of microplastics and nanoplastics are mainly in the organs that come into contact with them. These are primarily the digestive tract, where plastic particles from food and drink enter, but also the lungs, which accumulate microplastics contained in the air we breathe in. However, as we have already mentioned, nanoplastics in particular enter the bloodstream and accumulate in tissues throughout the body. Here is a list of some of the problems that can be associated with this:

• There is direct mechanical damage to the intestinal mucosa and subsequent impaired absorption of nutrients. The permeability of the intestinal wall is also increased, leading to the penetration of toxins and microorganisms into the bloodstream.
• The accumulation of plastic particles in the digestive tract leads to local inflammation. It is therefore possible that it also increases the risk of chronic inflammatory bowel disease.
• The balance of the gut microbiome is also deteriorating, both in terms of overgrowth and loss of certain bacterial species and a reduction in the overall diversity of the gut population.
• Plastic particles can contribute to the development of constipation.
• Inflammatory processes lead to changes in cellular metabolism within immune cells, which can not only impair our immunity, but can also lead to further worsening of inflammation.
• Nanoplastics can act as hormone disruptors.
• According to some research, they can also interfere with fat metabolism and contribute to obesity.
• Microplastics from the air can accumulate in lung tissue, where they increase the risk of respiratory diseases, including asthma.

In addition, plastic particles in our bodies can not only release various harmful substances, but their molecules can also interact directly with certain molecules in the human body – this is especially true for plastic molecules that carry an electrical charge. They can, for example, react with proteins, carbohydrates or nucleic acids, thereby completely changing their function. Their accumulation in cells can then lead to increased production of harmful free radicals and even apoptosis, or the death of the cell in question.

In addition, small plastic particles can also enter the placenta, where they can affect the developing foetus. This transfer has so far only been demonstrated in laboratory animals – when pregnant mice were exposed to microplastics, their offspring developed metabolic disorders, such as higher cholesterol levels and type 2 diabetes. The increased risk of cardiovascular disease was then passed on to the next generation.

In particular, changes in short-acting epigenetic reactions, i.e. especially in the area of histone modification and regulation by microRNAs, have been described as a consequence of micro- and nanoplastics. Effects on longer-term epigenetic processes, in particular gene methylation, have not yet been described. Of course, this does not mean that it does not exist – it may just require higher doses and longer-term effects.

What can we do about it?

As mentioned above, it is impossible to avoid microplastics and nanoplastics completely. Still, it is worth not giving up, because we can do something about it.

First of all, we can try to get a little less of them into our bodies, because the degree of their negative effects obviously depends on the dose. The second way is to try to strengthen our body so that it can eliminate as much damage as possible.

Less microplastics in the body

We can reduce the amount of microscopic plastic particles that enter our bodies by reducing the use of plastic in our lives:

• Limiting the purchase of bottled water, which contains many times more plastic particles than tap water, can be very beneficial.
• However, other beverages are a significant source of plastic microparticles, including those in glass bottles – plastic is found on the inside of their caps.
• Milk bottles are very problematic for babies on formula.
• It is advisable to limit the purchase of food in plastic packaging and the storage of food in plastic containers. Also, never heat food in plastic containers in the microwave.
• A significant source is tea bags containing plastic – a single bag can release up to 12 billion plastic particles when poured over boiling water!
• Indoor air contains significant concentrations of microscopic plastic particles – 5 to 10 times more than outdoor air. Therefore, regular ventilation is important.
• Textiles are considered a significant source of microplastics in interiors, so it is advisable to give preference to natural materials in the home.
• However, the air in cities is not problem-free either, containing up to twice as many micro- and nanoplastics as the air in suburban areas.
• Of course, the food itself is also a source of micro- and nanoplastics, regardless of how it is produced and stored. Due to the presence of microplastics in the soil and food chains, they are found in virtually all foods, but more in some. Very high concentrations have been found in seafood – fish, shellfish and algae. Surprisingly, honey, sugar, salt and chicken are also important sources.
• Microplastics are also found in cosmetics and can also enter the body when applied to the skin. Therefore, we should not use too many cosmetic products.

A more resilient organism

The second way is to try to make our organism more resistant to the harmful effects of microplastics. As we have already mentioned, the main problems caused by these particles are negative epigenetic changes, inflammation, disruption of the gut microbiome and hormonal regulation. Therefore, it is important to focus on a healthy diet, i.e. limiting pro-inflammatory and epigenetically harmful foods (sugar, saturated fats, alcohol, food additives) and, on the contrary, adding foods that have a positive effect on this area: fruits and vegetables, whole grains and legumes, high quality proteins, etc. Regular exercise is important – but given the significantly higher concentration of microplastics in indoor air, we should prefer to move outdoors.

Of course, dietary supplements can also help. While there are no studies yet that focus on examining individual nutrients and herbs in eliminating the harmful effects of microplastics, we can focus on substances that will support the functioning of the whole body.

In particular, it is advisable to choose substances with strong epigenetic and anti-inflammatory effects. We should alternate between them and in the long term prefer those that have very broad-spectrum effects – i.e. they affect a large breadth of epigenetic reactions (gene methylation, histone modification and microRNA regulation), and at the same time have anti-inflammatory effects. Typical examples include curcumin, EGCG, resveratrol, vitamin D3, quercetin and omega-3 unsaturated fatty acids. Broad-spectrum herbs include ginseng, boswellia and valerian.

It may also be advantageous to focus on nutrients and herbs that effectively support the regulation of gene activity by microRNAs. These are short-chain ribonucleic acids that carry no genetic information but can completely block the reading of some genes. In fact, it turns out that nanoplastics in particular can not only cause changes in microRNA production, but also that microRNAs may play an important role in protecting against the toxic effects of micro- and nanoplastics. For example, oligomeric proanthocyanidins or OPCs from grape wine are a very effective regulator of microRNA production.

For example, rhodiola can help regulate the disturbed hormonal system, but it is not suitable for long-term use. However, ginseng five-leaf, omega-3, vitamin D3, bayberry, zinc and selenium also have a positive effect.

In the intestinal tract, chicory, but also curcumin, quercetin or resveratrol can provide a good service.