There is a system in our brains called the reward system; essentially, the system is designed to "reward" us with pleasurable feelings when we make a choice that encourages our survival.
The brain releases feel-good chemicals into our body, thus propelling us to continue whatever behavior triggered that response.
In theory, the system works. However, according to Authority Nutrition, unhealthy food items often can register in the brain as a more powerful reward than natural foods; that’s how food addiction works.
Now, a study from researchers at Sweden's Uppsala University reports in Science that just like teenagers are inclined to become addicted to eating unhealthy fast foods, young fish become hooked on eating plastic in the seas, due to its high concentrations of polystyrene.
Researchers exposed perch larvae to different concentrations of polystyrene in water tanks; and according to Dr. Oona Lonnstedt, the fish hatched in highly contaminated water were “smaller, slower, and more stupid.”
The study showed that the junk-eating fish died at twice the rate of the others when they were exposed to predators; but perhaps what’s most surprising of all is that the fish demonstrated a preference for the plastic.
"They all had access to zooplankton and yet they decided to just eat plastic in that treatment. It seems to be a chemical or physical cue that the plastic has, that triggers a feeding response in fish," said Dr. Lonnstedt, according to BBC News.
“They are basically fooled into thinking it’s a high-energy resource that they need to eat a lot of. I think of it as unhealthy fast food for teenagers, and they are just stuffing themselves.”
In the study, the researchers have linked the declines of species like perch and pike to increased deaths at the juvenile stage. The argument is that plastics are impacting young fish across species, which has the potential to have “profound” negative effects on ecosystems.
"The observations we have so far are about the amount of plastic we find in the seas, and the amount we find within animals," Dr. Erik Van Sebille of Imperial College London said to BBC.
"Your intuition would say it is not good for a fish to eat plastic, but scientifically you want to prove it, you want to be able to show what the impacts plastic are having, and that has been very hard to determine until now, and that's why this is such a big paper.”
Huffington Post reports that President Barack Obama has signed a bill aimed at banning the potentially disastrous microplastics from rinse-off cosmetics by 2017; however, the majority of microplastics in the environment come from larger pieces of plastic breaking down, according to microplastic researcher Sherri Mason.
“I think the big movement is in finding plastics that can come from renewable resources,” Mason explained, saying that our goal should be to work toward materials that are “truly biodegradable.”