The overwhelming prevalence of plastic in our day–to–day lives is no foreign concept. We have widely accepted its abundance in our environment, food, and now its infiltration of our bodies. Particles as small as 20 micrometers can reach organs such as the lungs and liver, and those as small as 0.1 micrometers are destined to cross the placenta or blood-brain barrier. Although particles are less than 5 millimeters in size, microplastics have large effects on weight gain according to recent research. Although the mechanisms behind this tiny threat are still being researched, doctors across the country have recently drawn significant conclusions about their disruption patterns and why their presence in our bodies matters.
Microplastics are hormone disruptors that can mimic cortisol, estrogen, and other hormones. Cortisol is a hormone that regulates blood sugar levels and lessens inflammation. However, in high amounts, cortisol adversely affects weight by stimulating fat and carbohydrate metabolism, creating a surge of energy in the body. While this signaling pathway is vital to survival, this cascade of events results in an increased appetite, hence the correlation with increased weight.
Bisphenol A, an organic synthetic chemical commonly found in plastics, is a hardening agent present in water bottles, containers, and other household goods. While it is said to be generally safe for human consumption in low doses, research has found BPA to cause metabolic disruption, increased weight, and insulin resistance. A study conducted in February of 2023 confirmed that BPA exposure is linked to obesity, with a likelihood of 4.7 times greater compared to those who aren’t exposed. BPA exposure also showed an increase in inflammation, indicated by high interleukin-17A levels; whereas, lower levels correlated with reduced inflammation and improved metabolic health. Some brands will advertise their products to be “BPA free” which projects false hope of purity, as these manufacturers will replace BPA with BPS or other alternative chemicals for the illusion of safety.
Microplastics are largely found in ultra-processed foods like hot dogs, cookies, and chips, which make up more than half of the diet for adults in the United States. A recent study on the enhancement of microplastic consumption from take–out showed an alteration in the gut microbiome of young adults who consumed take–out a few times a week. A microbiome bacterial analysis revealed that participants experienced a rise in bacteria and pathogenic fungi, reflecting a shift toward a more inflammatory or disease-prone gut environment. The analysis also discovered a decrease in beneficial bacteria, indicating potential loss of anti-inflammatory and gut-protective functions, which results in poorer gut health, increased inflammation, and drastic metabolic changes.
“Some brands will advertise their products to be “BPA free” which projects false hope of purity, as these manufacturers will replace BPA with BPS or other alternative chemicals for the illusion of safety.”
Unfortunately, it’s impossible to eliminate plastic from our diets as it’s found in almost everything we consume. However, there are ways we can mitigate its consumption. Research has shown that plastic takeaway containers release a significant amount of microplastics when microwaved or while containing hot food. Environmental toxicologist Stephanie Wright advises, “I would start by not heating anything in plastic, or consuming hot liquid that has come into contact with plastic,” including Tupperware or ready–to–heat containers. Other less drastic, but effective, alternatives include avoiding bottled drinks, limiting processed and packaged foods, and buying whole foods.
The impact of microplastics on human health, especially their potential role in weight gain and metabolic disruption, is becoming increasingly clear. While completely avoiding microplastics is nearly impossible, making informed choices about food storage, preparation, and consumption can help mitigate exposure. As researchers continue to uncover the full extent of their effects, we must remain aware of how these “tiny threats” are reshaping our environment and our bodies.
