Assuming the fish is prepared properly and is sushi grade, how many times per week can I eat sushi without having to worry about mercury poisoning and/or health concerns? I'm not sure if the kind of fish is important, but I generally eat salmon, white tuna, and yellowtail.

  • Different fish do tend to have different mercury content, as some fish (like the various tuna) eat other sealife and accumulate higher concentrations of mercury within their body. nrdc.org/health/effects/mercury/sushi.asp
    – wkl
    Nov 8, 2011 at 21:54
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    Mostly only high order fish have high mercury content, and considering overfishing, you probably shouldn't be buying them anyway
    – TFD
    Nov 9, 2011 at 1:39
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    This seems like more of a health / nutrition question than a "food safety" deal. As birryree notes, the answer will likely depend a lot on what exactly you're eating - asking for advice on storage, handling, or preparation of a specific type of fish would be more along the lines of what's usually asked here.
    – Shog9
    Nov 9, 2011 at 8:31

2 Answers 2


Provided you go to a reputable sushi restaurant with good hygiene standards, you should have no problem in terms of bacteria or parasite-related health problems. Most fish used in sushi restaurants is flash-frozen at -20 degrees C (-4F), which kills parasites outright.

As for mercury, you can check the FDA's page detailing the amount of mercury in the various species of edible fish, to help you make an informed decision. They recommend that higher risk groups, such as pregnant women, limit their intake of certain fish to 12oz/week.

Generally, sushi is extremely healthy as it is low in fat and high in vitamins and minerals - Japan has the highest life expectancy in the world, after all: diet plays a big part in that.

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    Given your reference to Japanese life expectancy, it's important to realize that sushi isn't a very big part of the average diet in Japan; it's generally only an occasional indulgence for most people. So it likely plays little role in life expectancy.
    – JasonTrue
    Nov 9, 2011 at 4:55
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    It's like most imported cuisines, we tend to import the "party food" not the staples
    – TFD
    Nov 9, 2011 at 5:45
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    Fish in general is a big part of the average diet however. Nov 9, 2011 at 9:19
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    My personal observations travelling in Japan run counter to @JasonTrue -- raw fish is a staple, and sushi/sashimi is not such an indulgence. There are ridiculously expensive high end sushi restaurants which are, indeed, an indulgence. But there are also cheap sushi joints, and a donburi dish of rice topped with sashimi is a typical salaryman lunch.
    – slim
    Nov 10, 2011 at 16:08

Salmon are generally riddled with parasites, so if you purchase raw salmon, only use it if you know it has been frozen in accordance with FDA guidelines, which means it was previously frozen at a low enough temperature (lower than you can get in your home appliances) for long enough to kill the worms. Fresh off the boat? Cook the salmon.

Tuna and yellowtail (Japanese amberjack) are generally not a parasite risk, but if you live on the east coast and they call their local species of amberjack "yellowtail," it is a different species that often has worms, though, to my knowledge, it is not harmful to humans (but why risk it?).

The thing about delicious large ocean fish is that they are almost all predators, which means mercury will concentrate in them. A lot of "how much" will depend on local human influence and how far a species of fish ranges. I would imagine east coast/Atlantic US fish, with a lot of the traditional coal-fired power generation, is going to have more mercury issues. It's best to check with your local state agencies, which will have advisories for which types of fish present mercury risks and at what amounts (larger fish size will have more) and how often the fish can be safely consumed, if at all.

  • "Sushi grade" has no uniform or regulated definition in most places. It doesn't indicate that the fish was frozen at an particular temperature or for any particular length of time. Nov 20, 2018 at 18:29
  • @NuclearWang - You are correct. Edited, and thank you. Nov 20, 2018 at 18:34

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