[Column] Why eating microplastics is harmful

We inhabit a plastic-laden world where plastic fragments into minuscule pieces, rather than decomposing. These plastic particles have been discovered by scientists in various human organs such as the lungs, liver, placenta, breast milk, and blood. How harmful are these microplastics to our health? A study conducted in Italy and published in the esteemed journal NEJM on March 7, 2024 indicates a potential link between microplastics and heart health risks.

The accumulation of cholesterol and fat within the arteries supplying blood to the brain leads to their narrowing. When this narrowing disrupts blood flow, surgical removal of the deposits (plaque) becomes necessary. The research team conducted a comparative analysis between patients whose removed clumps contained microplastics, including nanoplastics, and those without such particles. They tracked the incidence of stroke, heart attack, and mortality over a 34-month post-surgery period to discern any disparities between the presence or absence of microplastics. The findings revealed that individuals with microplastics in their plaque faced a 4.5 times greater risk of stroke, heart attack, and death compared to those without. The researchers hypothesized that microplastics accumulate within blood vessels, triggering inflammation, and thereby elevating the likelihood of stroke and heart attack.

While the concern regarding the potential harm of microplastics persists, there remains a scarcity of studies examining the association between microplastics and disease risk in humans. A 2022 study conducted in China discovered a higher presence of microplastics in the feces of individuals with inflammatory bowel disease compared to healthy counterparts, though it solely established a simple correlation. The latest Italian study did not demonstrate causation, either. Still, the notable 4.5-fold difference in risk observed within a relatively short time frame of three years suggests a potential causal relationship. It's essential to acknowledge the likelihood of other variables influencing these outcomes. Notably, patients with microplastics exhibited higher incidences of heart disease, diabetes, and hyperlipidemia, along with a higher prevalence of male gender and smoking habits. Furthermore, the study's limitations are underscored by its small sample size, encompassing a total of 257 participants. The researchers acknowledged the necessity for subsequent follow-up studies.

How can we eat fewer microplastics? Some argue that reducing the consumption of large carnivorous fish and shellfish, which feed on filtered seawater, could help. However, it's worth noting that drinking water is the primary source of microplastics. Additionally, discarded bottles contribute significantly to the issue, as they eventually degrade in rivers and oceans, making their way into our bodies. According to the European Environment Agency, half of the plastic ever produced was made since 2000, with only 9 percent being recycled. Moreover, 40 percent of plastic is thrown away after just one use. This highlights the unavoidable nature of plastic ingestion for everyone on the planet. While the study of microplastics and health is best left to scientists, it is crucial for everyone to collaborate in reducing plastic use.

Jeong Jae-hoon is a food writer and pharmacist. He covers a variety of subjects, including trends in food, wellness and medications. This column was originally published in Korean in Joongang Ilbo on March 14, 2024. – Ed.