In case you haven’t seen this a Canadian researcher has made a bit of news north of the border with a presentation on fish and mercury. Dr. Gideon Koren says his latest work, looking at more than 100 women’s hair samples, has lead him to the conclusion that 20% to 30% of Canadian women of reproductive age have mercury levels high enough to damage the brain of a developing fetus.

This type of messaging is something we’ve seen before. And something that’s been criticized for making the shaky jump from levels of mercury in blood or hair to absolute harm, while in reality “[shedding] little light on the question of whether the health of the authors’ patients was affected by their methyl mercury exposure.”

We haven’t read the full study because it is not yet published in a peer-reviewed medical journal, but the early news reports leave us scratching our heads on several points. For starters, the report notes in only the second paragraph that despite the blockbuster opening line about potential brain damage, “…developing babies won’t be hurt in many cases…”

“Many cases?” How about any cases? From what we can tell, the researchers did not study the outcome on babies, he simply tested women’s hair and not even women who were necessarily pregnant.

This, still unreviewed, research did not study the impact of actually eating fish during pregnancy and the outcome it has on children. But plenty of other research has. Dr. Joseph Hibbeln’s study of 12,000 mothers and babies published in The Lancet did and the FDA’s exhaustive review of the seafood science literature did.

Dr. Hibbeln found mothers who ate the most seafood during pregnancy had children with the highest developmental outcomes, while the FDA found a “99.9 percent modest benefit” associated with baby’s brain development in mothers who ate plenty of fish during pregnancy.

The article notes that Dr. Koren reports finding, “the highest concentrations, well above the level where harm might occur… in Japanese Canadians, a group that consumes much more fish than mainstream Canadians.” Nowhere is the question raised, what about the entire county of Japan that eats more fish than Western cultures? What about the fact that that entire culture has some of the best health outcomes in the world?

Here’s the thing, reports about studies like these tend to fuel misconceptions about fish consumption during pregnancy based on conjecture. Meanwhile, the latest peer-reviewed science shows us that real babies of real-life pregnant women who eat real fish have the best real test scores of brain and eye development.

Devotees of the precautionary principle wince at these facts, but they are what they are. Perhaps the less we report on hair samples and the more we report on the actual outcomes, the better service we do for public health.