In addition to mercury and pesticides, fish may contain the chemicals that mirror how estrogen works in triggering breast cancer.

A group of scientists came to that conclusion after comparing samples from 27 samples of catfish and white bass donated by fishermen caught in five places along the Allegheny and Monongahela Rivers (from relatively unpolluted waters 36 miles upstream to industrial sites) in or near Pittsburgh with samples purchased at grocery stores.

No surprise, after mixing extracts taken from the skin, flesh and fat of fish with MCF-7 breast cancer cells full of estrogen receptors, the cell lines proliferated, particularly near sewage treatment plants, sewer outflows (where residues from antibacterial soaps and unused pills are dumped) and in the industrial sector of the Monongahela River.

What should really scare you: Extracts from white bass bought at a local grocery store, when exposed to MCF-7, caused breast cancer cells to grow too, one reason why one scientist called fish today's health sentinels. just like canaries in the coal mine 100 years ago.

All the more reason to enjoy the benefits of fish without the toxic chemical load by taking a high quality fish oil or krill oil daily.