Here is a weird coincidence: Microplastics were first used in cosmetics in the 1970s, when they were also first identified as a pollutant in the oceans.
It was around this same time that the world started getting fatter: Obesity rates have tripled since 1975.
Could there be a link between the chemicals found in plastics and the global obesity crisis?
New research has found that plastics, which enter the human food chain during our time in the womb, are a probable driver of obesity.
The plastics contain thousands of chemicals, some of which are already known to be disruptive to our endocrine system, where hormones regulate hunger, appetite and our metabolism.
It’s this disruption to our metabolism that has caused much of the world to go on an unhealthy sugar-based eating jag.
What did the scientists find?
Researchers from the Norwegian University of Science and Technology (NTNU) looked at 34 different plastic products in the laboratory to see what chemicals they contained.
These were commonly used items such as “yoghurt containers, drink bottles and kitchen sponges”.
The scientists found more than “55,000 different chemical components in these products and identified 629 of the substances”.
Eleven of them are known “to interfere with our metabolism, called metabolism-disrupting chemicals”.
“Our experiments show that ordinary plastic products contain a mix of substances that can be a relevant and underestimated factor behind overweight and obesity,” said Dr Martin Wagner, an associate professor at NTNU’s Department of Biology.
Some chemicals were known disruptors
These include bisphenol A (BPA), which has been used to make plastics and resins for more than 60 years.
Apart from the impact on hormone regulation, BPA is thought to affect the health of the brain and prostate gland in foetuses, infants and children.
Phthalates are also known endocrine disruptors. These are industrial chemicals used to soften PVC plastic.
They’re also used as solvents in cosmetics and other consumer products and can damage the liver, kidneys, lungs and reproductive system.
But wait, there’s more
Chemicals from one-third of the plastic products investigated in the new study “were found to contribute to fat cell development in laboratory experiments”.
The substances in these products “reprogrammed precursor cells to become fat cells that proliferated more and accumulated more fat”.
The scientists say these effects weren’t limited to endocrine disruptors –the fat accumulation was a result of other processes.
This is a nasty mystery because it means that “plastics contain currently unidentified chemicals that interfere with how our body stores fat”.
As Dr Johannes Völker, the first author of the study, observed: “It’s very likely that it is not the usual suspects, such as Bisphenol A, causing these metabolic disturbances. This means that plastic chemicals other than the ones we already know could be contributing to overweight and obesity.”