Seafood Science Since Madison
What's Really Happening in the Great Mercury DebateIn March 2007, barely seven months after the International Conference on Mercury as a Global Pollutant was held in Wisconsin’s capital, the event’s organizers publicized their breathless claim that mercury exposure from the fish we eat constitutes a global public health threat. But during those months, a series of landmark scientific publications made this “Madison Declaration” and its frightening language a moot point, at least for consumers whose only direct encounter with mercury comes through traces that have always been present in the fish they eat.
Evidence continues to mount that fish, on balance, deserves its reputation as a health food. Real-world neurological health risks associated with eating fish are near-impossible to identify in individual consumers, and the medical literature has failed to provide a single fish-related mercury poisoning case in the United States. But the health benefits of fish consumption are well documented and generally uncontested. (The chief dissenter remains the animal “rights” lobby, whose argument for a global diet devoid of all animal protein is motivated by political ideology, not human health concerns.)
Recent years have seen a squabble between competing fish-mercury studies carried out in the Seychelle Islands (which found no health risk to children from their mothers’ prenatal fish intake) and the Faroe Islands (which claimed to identify a developmental risk too small to be seen in individuals, yet perceptible in a large population). But now they have both been eclipsed by a study more robust than either. The last scientific word on the subject is that pregnant women who eat the most fish appear to have the smartest children.
The peripheral debate over whether retailers should scare pregnant women away from the fish counter with “warning” signs about trace levels of mercury took an unexpected turn, thanks to the law of unintended consequences. The federal government’s Institute of Medicine has warned that other Americans (post-menopausal women and men of all ages, for instance), for whom even the most creative mercury fabulist cannot construct a logical reason to fear fish, also read and obey such signs. And the public health threat posed by their loss of seafood’s health benefits dwarfs anything mercury traces could ever visit upon newborn babies.
The ongoing Faroe Islands research into mercury-related health risks also had a self-induced hiccup, as the study’s research team acknowledged publicly that their estimation of mercury’s public-health threat is based on a population whose dietary mercury comes from whale meat, not fish. Since Faroese natives eat copious amounts of pilot whale, ingesting mercury without the fish-related health benefits other populations enjoy, their diet now appears to be a glaringly inappropriate model for what happens when modern mainlanders eat seafood.
Researchers on the Faroe Islands team continue to cling to their self-anointed position as global arbiters of mercury health hazards. They insist that their study is all the more relevant to toxicology since mercury in whales is naturally separate from the omega-3 fatty acids, selenium, and other beneficial nutrients that typically accompany the toxin in fish. But while this is an interesting intellectual exercise, it tells average consumers nothing about the real-world risks and benefits of their seafood consumption.
That practical message has been delivered by a comprehensive review of seafood science, published by the Institute of Medicine. The news for consumers is unequivocally good. The justification for alarm is practically nonexistent. And the alarming Madison Declaration now seems to have been hopelessly obsolete before its ink was dry.
