Mercury Poisoning from Tuna

Over the years, we’ve had to read a number of stories about non-B12-supplementing vegans coming down with neurological problems. And while it’s unfortunate that this man got mercury poisoning, it was a relief to see for once a story implicating animal products instead.

The January 24th issue of The Lancet has a case study of a 59-year old Singapore man who developed severe neurological problems due to eating tuna every day. He originally went to the hospital for lower back pain where the staff noticed that he was suffering from poor memory – he later couldn’t remember why he had gone to the hospital. His speech was slow, he stooped, and had problems walking.

Although his urine did not show mercury, his blood level was 28 μg/L; normal is less than 15 μg/L.

Sources other than the diet were ruled out (he did not have mercury fillings). He could not remember what he typically eats, but his cousin reported that he eats tuna every day and also bought Chinese herbal tea (which can contain mercury) from unlicensed traditional practitioners.

With treatment using the drug penicillamine, and eliminating tuna and the herbal tea, his mercury level got down to 19 μg/L. After five months, his symptoms had improved, but had not completely resolved.

I don’t suppose the Center for Consumer Freedom will be covering this story…

Source: Ho RCM et al. Amnesia, political ambition, and canned tuna. Lancet 2009; 373: 352.

6 Responses to “Mercury Poisoning from Tuna”

  1. Nick Says:

    Does FDA approved (i.e. US) tuna pose the same degree of risk, or is part of the blame due to different food standards in east-Asian countries (e.g. melamine in China)?

  2. Jack Norris RD Says:

    My understanding is that while the FDA tests fish occasionally to measure the amount of mercury in various species, there is no system for screening out individual fish that might be especially high in mercury. Here is a December 12, 2008 Washington Post article that discusses proposed FDA regulations and the controversy they caused:

    FDA Draft Report Urges Consumption of Fish, Despite Mercury Contamination

    Here is a link from the 2004 mercury in fish advisory released by the FDA and EPA:

    What You Need to Know About Mercury in Fish and Shellfish

  3. Jeannie Says:

    Excellent information Jack! There is also the issue of other contaminants in fish (wild caught or farmed, I imagine).

    The radio show Living on Earth did a nice piece on this some time back:

    Living on Earth

    Bad News from the Blubber
    Air date: February 15, 2008

    “The ocean is downhill of everything on earth, and the result is that everything flows into the ocean from higher ground, and that means it’s the ultimate cesspool basically of the world. Industry has always said, ‘The solution to pollution is dilution’ and it’s absolutely true—if you take some poison and drop it somehow into the ocean or it eventually gets there in streams, it gets diluted down to such low concentrations that in fact, it is harmless. But then a totally insidious thing happens and that is—it dissolves into the oil droplets that are part of the—well they are the base of the food chain and so anything we produce that animals can’t handle they then can’t get rid of and the result is they have to store it and they pass it up foodchains.

    “Many of the substances that we’re concerned with are fantastically insoluble in water. They are highly soluble in fat. So what happens is that they end up in the ocean water, anywhere in parts per trillion or parts per quadrillion, so hugely diluted. But as soon as they get into fats they end up in very, very high concentrations because the fats can hold lots of them. The trouble is the animals don’t have any way of dealing with them so they store them, and then they get passed on when that animal gets eaten by some other animal.

    “So here on your plate is a pound of swordfish. It took a million pounds of diatoms to create that one pound—not the whole fish—just that one pound. A million pounds is 500 tons, so it took 50, ten-ton truckloads of diatoms to make that one pound of swordfish. So you take all those trucks and you park them along a row, it’s about ten blocks long, and to the end of that row you attach your liver and with it you detoxify that entire line of trucks. And that’s what you do when you eat a pound of swordfish. And then maybe tomorrow you have another pound. I adore swordfish. I would do anything to have a piece of
    swordfish except eat it.”

  4. beforewisdom Says:

    I find it amazing that in the year 2009 health experts, credentialed, self-appointed and otherwise are STILL promoting fish as a health food.

    Aside from toxins the oceans are in danger of being dead within 40 years due to over fishing and pollution.

    Eat something else people!

  5. Vegan Bites: Valentine’s Edition Says:

    […] Signs of mercury poisoning: can’t remember eating tuna, can’t remember why you went to the hospital. (link) […]

  6. EC Garrison Says:

    No, the Center for Consumer Freedom will not be covering this story…..they are too busy focusing their efforts on dreaming up lies to confuse and irritate would be vegans. They spread lies and misinformation and it is so obvious just by reading through anything they publish. And they dare to call themselves “consumer FREEDOM”??? There is no freedom where there is deceit.

    Meanwhile, people will continue to eat animals from the oceans as if they are a health food.

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