From David Martosko, Director of Research for the Center for Consumer Freedom:

Want propaganda with your tuna?

I consider myself an open-minded person. So just because a writer decides to take an unwarranted pot-shot at the nonprofit group I represent, just because she exemplifies the woeful state of what passes for science journalism, just because she relies on Internet gossip to try and discredit my work, just because she seems blissfully unaware of the public-health damage she’s doing, do I dismiss her too-clever-by-half attempt to put a skull and crossbones on fish, and anyone who dares to defend it?

Of course not.

So when Newsweek blogger Sharon Begley came out with her unprincipled attack on good science that dares to contradict conventional wisdom, I didn’t reflexively think, “This is the publication that famously retracted a flagrantly false story about U.S. servicemen supposedly flushing the Quran down a toilet at the military prison on Guantanamo Bay.” I didn’t think, “This is the writer who once attempted to diagnose mental illness in the President of the United States from a distance.” I didn’t think, “This is the journalist whose opinions about the global warming debate have been publicly disavowed by a Contributing Editor to her own magazine.” I didn’t think, “This is a Senior Science Editor whose science credentials consist of a bachelor’s degree in something called “combined sciences” with an emphasis in physics, not biology or toxicology.

No, I actually took a critical look at Begley’s objections on scientific grounds. What I found:

Begley disagrees with our assertion that the Food and Drug Administration’s “Action Level” for mercury in fish has a 10-fold safety margin built right in to it. Her view of the history behind the Action Level’s implementation is interesting but irrelevant.

Here’s what the FDA says: The “Action Level” for mercury in fish “was established to limit consumers' methyl mercury exposure to levels 10 times lower than the lowest levels associated with adverse effects.” That’s a ten-fold (1,000 percent) safety margin. So yes, if a piece of sushi registers 1.4 parts-per-million, that’s not actually a reason to panic. Do the math. It’s less than one-seventh the level that might (and I underline might) be a cause for concern.

Begley claims that “there is no ‘safe’ level of mercury in fish.”

That’s the same as saying that it’s always “unsafe” to eat fish, since every single fish on the planet contains a trace level of mercury. It’s been there since the first caveman sharpened a stick and went looking for brook trout.

Begley claims that the Environmental Protection Agency’s “Reference Dose” for mercury is “an amount of mercury consumed daily,”

This is flat-out wrong. Here’s how the EPA itself defines the idea of a “reference dose” (RfD): “In general, the RfD is an estimate (with uncertainty spanning perhaps an order of magnitude) of a daily exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime.” Underline “lifetime.”

Here’s the basic information you need to know. Unless you’re eating more fish than the average Japanese (who eat about eight times more fish than Americans), the entire idea of mercury as a contaminant shouldn’t be on your radar. (Japan’s government said as much today.)

Study after study has shown that the established, well-documented health benefits of eating fish (including tuna) far outweigh the hypothetical risks. Hypothetical? Absolutely. So far, the number of documented U.S. mercury-poisoning cases in the scientific literature from eating fish is zero.

And if you’re pregnant, fear not. The largest study of its kind, published last year in The Lancet (England’s most prestigious medical journal) showed that pregnant women who eat the most fish have children with the best IQ potential. The moms-to-be who swear off fish wind up generating children with stunted neurological growth. The U.S government fish-mercury advisory, the researchers concluded, “causes the harm that it was intended to prevent.”

All too often, people trying to balance the risks of mercury against the benefits of fish give up. Somehow we have let environmental activist groups get away with claiming that if you worry about omega-3 fatty acids you’ll subject yourself to harmful levels of mercury. More nonsense.

A comprehensive review from Harvard concluded recently that hypothetical down-sides related to mercury should take a back seat to cardiopulmonary up-sides. (Don’t take this issue up with me. Take it up with Harvard.) So this business about warning signs in grocery stores should be exposed as pure lunacy.

My mother used to prod me to eat fish on Fridays, saying it was “Brain food.” She was right.