Dr Michael MacDonald, Senior Consultant Cardiologist at the Harley Street Heart & Vascular Centre, speaks to ForLife about the dangers of these environmental pollutants on our body and heart health.

Microplastics, plastic particles that are less than 5 milimetres in length or about the size of a sesame seed, have been recognised as an environmental pollutant for years. But did you know that they can also be present inside the human body and endanger our health?

In recent decades, microplastics have not only been detected in human blood and feces but have also been found in human lung tissue samples.

How do plastic particles make their way into the body?

According to Dr Michael MacDonald, microplastics and nanoplastics enter the body mainly via inhalation, ingestion, and skin contact.

“Plastic particles we ingest through food or water we consume make their way into the bloodstream through the digestive tract, while airborne plastic particles are absorbed into our capillaries and veins in the lungs depending on their charge, particle size, and other properties. Some studies indicate that plastic particles can even enter our system through open wounds or glands on the skin.

In fact, human beings could be consuming up to 52,000 particles of microplastics annually, and excreting up to 1,000 pieces of microplastics daily.

How do microplastics harm the body?

Once they are inside our body, these micro plastic particles can be absorbed by cells and impair or damage our metabolism and signaling systems, says Dr MacDonald.

A study in mice found that the accumulation of plastic particles in the kidneys could cause biotoxicity, and lead to weight loss, an increase in their death rate, and signs of kidney damage. Meanwhile, rats that consumed 0.5, 5, and 50 mg/L of microplastic particles for just 90 days demonstrated cardiovascular toxicity that led to structural damage to the heart and its dysfunction.

“The exposure to chemicals and industrial additives in plastics, such as pigments, plasticisers, and stabilisers, can lead to a variety of adverse effects on human health such as hypertension, myocardial infarction, angina, and atherosclerosis, impaired development of the brain and central nervous system, as well as inflammatory conditions. For example, exposure to a plasticiser known as phthalates has been shown to slow the heart’s rate and rhythm, which can lead to insufficient oxygen-rich blood reaching the organs and tissues, and impairs their function,” explains Dr MacDonald.

“The alteration of biological processes in our body could potentially harm those with pre-existing comorbidities. It’s also thought that certain diseases like inflammatory bowel disease, alcoholic liver disease, type 2 diabetes, chronic kidney disease, chronic heart failure and depression can cause dysfunction in the intestinal epithelial barrier and enhance the entry of microplastics through the intestinal membrane and/or lining, but further study is required in this area.”

Dr Michael MacDonald, Senior Consultant Cardiologist at the Harley Street Heart & Vascular Centre

Dr Michael MacDonald, Senior Consultant Cardiologist at the Harley Street Heart & Vascular Centre

How can we reduce microplastics in our body?

While we cannot control how our body responds to exposure from harmful chemicals and pollutants, we can try to reduce our exposure to them.

Dr MacDonald says, “We can try to reduce the quantity of ingested plastic particles in our food by consuming more fresh and organic food, as well as by reducing the intake of highly processed foods such as soft drinks, packaged snacks, and fast food. This can also reduce our intake of artificial colours, preservatives, and stabilisers, which are detrimental to our health.”

“Smokers are also at an increased risk of microfibre exposure from cigarettes, so quitting or reducing smoking is recommended, especially as it is also good for our overall health. Exercising regularly can also be beneficial in removing pollutants from our bodies, as it can help to strengthen the heart, promote a healthy lymphatic system, increase the flow of oxygen-rich blood, maintain proper functioning of the digestive system, and improve waste elimination.”

He also emphasises the importance of regular check-ups to assess and monitor heart health, and health of the kidneys and lungs, which are prone to damage from the accumulation of plastic particles in the blood.

Unfortunately, because of the prevalence of plastic debris in the bottom of the oceans, we cannot rule out the presence of micro plastics even in fresh seafood, the water we drink, and the air we breathe. This is just another compelling reason why we should strive to reduce the use of plastic-based products and properly dispose of chemical-containing products, while educating others around us to do the same.


Featured photo by Dreamstime.
Dr Michael MacDonald’s photo courtesy of Harley Street Heart & Vascular Centre