Pollutants in fish may inhibit our natural defence system

Los Angeles: Environmental pollutants found in fish may obstruct the human body's natural defence system to expel harmful toxins, a new study has warned. This information should be used to better assess the human health risks from eating contaminated seafood, according to researchers at the University of California - San Diego.

A protein found in cells of nearly all plants and animals, called P-gp, acts as the cell's bouncer by expelling foreign chemicals from the body. P-gp is well known for its ability to transport therapeutic drugs out of cancer cells and, in some cases, rendering these cells resistant to multiple drugs at once.

To determine how effective P-gp is at ridding cells of industrial and agricultural pollutants found in seafood, collectively known as persistent organic pollutants (POPs), the research team conducted a biochemical analysis of P-gp proteins from humans and mice against POPs.

The scientists focused on POPs most commonly found in human blood and urine, and also detected in the muscle tissues of wild-caught yellow-fin tuna. The pollutants included older "legacy" compounds such as the pesticide DDT as well as newer industrial chemicals, such as flame retardants.