NGOs using fear, not facts, in mercury in tuna debate


Sean Murphy, SeafoodSource online editor

Published on
March 3, 2015

Recent announcements by the U.S. government regarding seafood’s role in the American diet have brought out the expected criticisms by NGOs based on cherry-picked advice that, when examined closely, do not actually make up the “smoking gun” that the NGOs want the American public to believe.

I am once again compelled to examine the arguments that canned tuna in particular is some sort of toxic agent poisoning the bodies – and wombs – of unwitting Americans who trust the industry too much, in the hopes of injecting some sanity into the discussion. This may be a bit quixotic since I don’t expect the NGOs to change their tune anytime soon. As Jon Stewart has often said, you can’t fix crazy.

Mercury in seafood, and tuna in particular, returned to the spotlight last June, when the U.S. Food and Drug Administration (FDA) announced it was drafting new dietary guidelines for pregnant women. Among them, an encouragement to eat more fish, as studies show it can benefit child development.

That draft process is still going on, and no doubt the FDA will be using a report released on 19 February when making its final decisions. Commissioned by the Obama administration, the Scientific Report of the 2015 Dietary Guidelines Committee drew many conclusions about food safety, but on fish the report found, “Regarding contaminants, for the majority of wild caught and farmed species, neither the risks of mercury nor organic pollutants outweigh the health benefits of seafood consumption.”

In response to that, the Environmental Working Group (EWG), a nonprofit NGO that its website says is “dedicated to protecting human health and the environment,” issued a statement blasting the report.

“It is shocking that a committee advising our government on critical public health decisions got this issue so wrong,” Sonya Lunder, senior analyst at EWG, said. “Pregnant women and children should not eat albacore tuna and other fish high in mercury because this heavy metal is toxic to the nervous system and can undermine a child’s development.”

Michael Bender, director of the Mercury Policy Project, an NGO dedicated to eliminating the risk of mercury toxicity in the environment, also weighed in. In the same EWG statement, he wrote: “Tuna is responsible for nearly seven times more mercury exposure than the four high-mercury fish that the federal Food and Drug Administration advises pregnant women not to eat. So why would the proposed 2015 Dietary Guidelines recommend that pregnant women eat more of it?”

Finally, the EWG quoted Harvard School of Public Health’s Dr. Philippe Grandjean as saying the report’s authors “ignore a substantial body of evidence” that high amounts of mercury during pregnancy can cause problems with fetal brain development.

It’s not surprising that the EWG is piping up again, given their response to the FDA’s announcement last June, which came under the catchy title, “Five things FDA and (the U.S. Environmental Protection Agency) didn’t tell you about seafood safety.”

To be fair, the EWG and related groups cite plenty of sources they claim back their assertions, and offer links to more than a dozen studies conducted over the past several decades.

Two of the reports, one from Minamata, Japan, in the 1950s and another a decade later in Iraq, depict horrifying accounts of children being permanently harmed by excessively high concentrations of mercury in the food they ate. These are routinely cited by EWG and others, despite their being one-off situations that have not been duplicated since.

Of the rest, no reports actually condemn the eating of fish outright, and none of them singles out tuna. Two telling examples are studies where a team including Emily Oken from Harvard Medical School, one in 2005 and a follow-up in 2008, found that mercury may be dangerous at any level, yet many subjects whose mothers ate lots of fish during pregnancy actually had far better cognition that one would expect if we assume, as EWG wants us to think, that mercury is the only thing to consider here.

Oken wrote: “The benefit is conferred by consuming fish types with the combination of relatively little mercury and high amounts of beneficial nutrients. This explanation is supported by results … in which adjustment for mercury strengthened the observed positive association of fish intake and cognition.”

One more quote, this one from a 2012 report from the U.N.’s Food and Agriculture Organization and the World Health Organization, also cited by EWG: “When comparing the benefits of (fatty acids found in fish) with the risks of methylmercury among women of childbearing age, maternal fish consumption lowers the risk of suboptimal neurodevelopment in their offspring compared with the offspring of women not eating fish in most circumstances evaluated.”

Most of the reports the EWG cites as clear evidence supporting their claims make similar statements, that mercury is dangerous, but the benefits of eating fish far outweigh the risks of elevated mercury exposure, unless we’re talking about tilefish, king mackerel, swordfish, shark, or maybe pilot whale – in other words, fish few people eat anyway, at least compared to canned tuna.

Since we’re citing scientific reports, here’s one from Nick Ralston, a scientist at the University of North Dakota, talking about the role of selenium in even further mitigating the risks of mercury in seafood, especially common types such as tuna.

As to the allegation the FDA is not considering how high tuna can be in mercury, that’s not true either. The FDA recently did an exhaustive study of a number of toxic metals, including mercury found in canned tuna, and found pregnant women can eat way more tuna that most people would like to in a week before even beginning to worry about mercury’s risks overtaking the benefits.

These studies are just as available as the volume of work the EWG is citing, so why does the EWG consider advice to eat more fish “shocking?” Is it that they haven’t read the FDA study, or Ralston’s, or that they didn’t look closely enough at their own citations? I don’t know, but at the very least I invite the industry to use the works cited here as a reference for the next time the NGOs take aim. In a perfect, world, I would hope the NGOs might take a closer look at their own data too, and consider they may be wrong, out of date, or using hyperbole to substitute for facts.

But I don’t have high hopes of that. After all, you can’t fix crazy.

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