Worrying About Mercury in Seafood? Don’t.
Dear Natural Health Solutions Reader,
Are you restricting your fish consumption because of the FDA’s warnings about mercury contamination?
Any stockbroker knows fear is stronger than greed. So it’s easy to persuade people to fear, and avoid, fish.
But perhaps we’d be smarter to be greedy for its benefits. Fish are packed with omega-3 fatty acids and other nutrients that support heart and brain health.
So what’s the bottom line?
Since 2004, the FDA has recommended that children and pregnant women avoid swordfish, tilefish, shark and king mackerel, and eat no more than two meals a week of all other ocean fish in order to keep their consumption of methylmercury below dangerous levels.
It appears that after that warning, other people stopped eating fish as well. After all, if it’s bad for fetuses and children, how healthy can it be for me?
Fish consumption in the U.S. dropped about 15 percent after its 2005 peak – probably as the FDA’s warning percolated into popular culture.
But that advice is increasingly criticized as having been based on cherry-picked data and a poor understanding of the mechanisms at play.
One study that government officials relied heavily upon involved the Faroe Islands, a territory of Denmark, where residents suffered from severe mercury poisoning due to seafood consumption.
Pilot whale meat was the culprit – a source that everyone admits is uniquely high in mercury. However, since it’s illegal to possess whale meat in the U.S. unless you are an aboriginal Alaskan, how relevant is that risk to the average American?
Yet caution with mercury is warranted. Some recent studies show adverse effects of mercury on brains, especially developing brains, at levels many times lower than the 2004 guidelines.
So here’s the good news. Evidence shows selenium, an essential mineral for human health, is likely the key to safely eating seafood.
One of the best dietary sources of selenium is fish. And researchers are uncovering a crucial relationship between selenium and mercury. It may help explain why eating pilot whale meat was such a disaster for the Faroe Islanders.
As it turns out, the higher the ratio of selenium to mercury in a fish, the safer it is to eat.
Why?
The reason mercury is a neurotoxin is not because mercury itself is dangerous, but because it keeps selenium from doing its job. Mercury naturally binds to selenium, preventing selenium from performing vital roles in the brain, including reducing oxidation from the brain’s robust use of oxygen.
That’s why selenium deficiency impairs thinking and memory. But as long as you are eating fish with substantially more selenium than mercury, you avoid a mercury-induced selenium deficit.
It should be noted that most adults have plentiful reserves of selenium from various dietary sources. Those most at risk from mercury from any source are children and developing fetuses.
Recent tests show that pilot whales have much higher levels of mercury than selenium, which could explain the (albeit subtle) neurological impact of mercury on Faroe Island children.
So skip the pilot-whale sashimi – probably not on your bucket list, anyway.
Instead, everyone—including pregnant women and children– should eat wild-caught salmon, sardines, herring and black cod at least twice a week, as these are excellent sources of omega-3 fats and relatively rich in selenium.
Indeed, research indicates that virtually all ocean fish sold in American stores contain enough selenium to neutralize the mercury they contain.
There are rumors that the FDA will readjust its guidelines in the near future to reflect this emerging data. Let’s hope it does.
Sincerely,
Brad Lemley
Natural Health Solutions
Citations
(NHANES III) 3rd National report on human exposure to environmental chemicals, Tech. Rep., Centers for Disease Control and Prevention, 2005.
(NHANES IV) 4th National Report on Human Exposure to Environmental Chemicals, Tech. Rep., Centers for Disease Control and Prevention, 2009.
Mercury Toxicity and Treatment: A Review of the Literature, Journal of Environmental and Public Health, Volume 2012 (2012), Article ID 460508, 10 pages.
