Mercury mmm-mmm good

Marvin Gaye sang about "fish full of mercury" ages ago, but the debate about the safety of eating fish goes on.

The newest wrinkle: The type of mercury found in fish is less toxic than other types, according to a paper published in today’s issue of Science.

Researchers tested swordfish, orange roughy and sand sole and found methylmercury cysteine, not methylmercury chloride -- the type assumed when governments have warned pregnant women and children against eating too much fish.

But before you sigh with relief and head for the sushi bar, realize that the basis for thinking this type of mercury is safer is based, not on human studies, but on a study of zebra fish larvae.

Mercy, mercy me.