Certain pollutants, found in particular in tuna, would inhibit the capacities of the immune system in humans, according to an American study.
Persistent organic pollutants (POPs) could interfere with the functioning of the immune system. A study published in the scientific journal Science Advances, carried out by the University of San Diego (California) looked at industrial pollutants found in fish and seafood. Researchers have discovered that these molecules can block a specific protein, P-gp, which contributes to the efficiency of our immune system.
The P-gp protein is present in large quantities in animals, certain plants, and in humans. It helps to expel toxins present in cells, and is particularly known for its ability to prevent therapeutic molecules from entering cancer cells. It provides the body with effective defense mechanisms.
Flame retardants singled out
The researchers determined the effects of persistent organic pollutants on these P-gp proteins. They found that they impair the human immune system. They interfere with proteins which can no longer fulfill their mission. In particular, the study showed, for the first time, that flame retardants (PBDE-100) used for foam and plastic padding bind with proteins.
The pollutant attaches to the protein like a chemotherapeutic molecule or a drug. But, instead of being transported out of the cell, POP inhibits the protein’s ability to perform its defense function. “It is very astonishing to see how the persistent pollutants interfere with the cells supposed to protect the organism from the external aggressions”, according to Jacob James, director of the Waitt foundation, which carried out this study.
“We have found that these inhibitors of immune system efficiency are present in the fish we eat,” says Sascha Nicklisch, co-author of the study. The researchers point out that pesticides (DDT) and flame retardants have been detected in the muscle tissue of wild yellowfin tuna in particular. “When we eat contaminated fish, we may reduce the effectiveness of our immune system,” comments Amro Hamdoun, co-author of the study.
.
