The eco-friendly alternative to petroleum plastic may not actually be human friendly, a new study has found
In an effort to reduce the build up of microplastics in our environment, scientists have been working on biodegradable alternatives.
A popular solution is the use of starch-based plastics which are created from natural starch sources such as corn, potatoes, rice and wheat. These biodegradable plastics are seen as a safer solution and are touted as eco-friendly – and they certainly are, when compared to regular plastics made from petroleum.
However, while this new generation plastic is technically biodegradable, they are not biodegradable in all environments: they may not break down completely in natural environments, potentially leading to the formation of smaller microplastics.
So we might potentially be looking at a future in which starch-based microplastics and nanoplastics are widely distributed throughout the environment, possibly not as ubiquitously as the older generation of microplastics, but certainly something that may be problematic.
Another potential problem has come to light today, with the publication of new research in the American Chemical Society’s Journal of Agricultural and Food Chemistry. Conscious of the fact that we still don’t know much about how starch-based plastics might affect the human body, a research team led by Yongfeng Deng studied their effects using mice.
The researchers divided the mice into three groups. One group ate normal food, while the other two groups ate food mixed with low or high amounts of starch-based microplastics. These amounts were based on what a typical human might consume each day. The mice were fed this way for three months. Afterward, the team examined their organs, how their bodies processed nutrients, and the bacteria in their guts.
They found that mice who ate the plastics showed damage in several organs, especially in the liver and ovaries, with the high-dose group showing worse effects. In contrast, the mice that ate normal food had healthy organs. The mice that consumed the plastics also had trouble managing blood sugar and fats, with noticeable changes in certain biological markers related to metabolism.
Additionally, the study found changes in the genes related to body functions and an imbalance in gut bacteria. The researchers believe this might affect the animals’ internal body clocks.
Deng, the corresponding author of the study said: ‘Biodegradable starch-based plastics may not be as safe and health-promoting as originally assumed.
‘Prolonged low-dose exposure to starch-based microplastics can lead to a broad spectrum of health impacts, particularly perturbing circadian rhythms and disrupting glucose and lipid metabolism.’
The research is available to buy here.