Tuna Safety

January 16, 2006 2:33 PM

How safe is albacore tuna?

I love tuna fish. I would eat it every day if I thought I could do so without slowly poisoning myself. I've tried to get some kind of reasonable answer to the question of what quantity albacore tuna is safe in, but I haven't found it. My tuna of choice is Trader Joe's olive-oil packed albacore.

posted by clockzero to food & drink (8 comments total)

Wow, two fish questions in one day. I'll recommend what I recommended to the previous asker, which is to check out this series that The Chicago Tribune did on levels of mercury in fish. I do know they talk about albacore tuna specifically (and about several other kinds of fish). It also tells you exactly what quantity of each fish is supposed to safe for you to consume in a week.
posted by lilybeane at 2:35 PM on January 16, 2006

See calculator on Tribune website.
posted by acoutu at 2:36 PM on January 16, 2006

The FDA recommends no more than two servings per week for women of childbearing age to avoid the chance of mercury-related birth defects. That should give you some idea. They also say "If you regularly eat types of fish that are high in methylmercury, it can accumulate in your blood stream over time. Methylmercury is removed from the body naturally, but it may take over a year for the levels to drop significantly. "
posted by cali at 3:27 PM on January 16, 2006

Wow. I had no idea that the "chunk light" tuna (skipjack) has 1/3 the mercury of albacore. That is certainly good to know. Great link.
posted by unknowncommand at 4:17 PM on January 16, 2006

Ah, but I didn't see this:

The government has recommended that children and pregnant women eat canned light tuna because it generally contains less mercury than canned albacore does. Yet industry officials acknowledged in interviews that tens of millions of cans of light tuna sold each year are made with a species that on average contains just as much mercury as albacore.

Darn.
posted by unknowncommand at 4:32 PM on January 16, 2006

how many cans of light tuna are made a year? say it's 1 per person and the populn of the usa is 300,000,000. if "tens of millions" means 30,000,000 then that's just 10% of cans. so what's the effect of that? every time you eat 9 cans of light, you get one that's not (on average). let's say a can of normal tuner has 1 unit of mercury. with 9+1 you end up eating 9*1/3 + 1 = 4 units. so an average dose is 4/10 = 40% instead of 33% (one third).

so those extra cans you are worrying about raise the level, on average, by 7% over 33%. 7/33 is about 1/5 so to compensate you need to eat 20% less tuna than you would have otherwise.

so if you thought it was ok to have 10 cans a month, drop that to 8 and you've compensated for the odd extra can with the higher levels.

of course, you want that "on average" to be true. so don't buy all your tune from the same maker on the same day (in case you hit a bad batch).

disclaimer - i just pulled those numbers out of a hat; i have no expert knowledge of tuna, mercury, etc etc, and i may have made a mistake.
posted by andrew cooke at 5:02 PM on January 16, 2006

As far as I've been able to find, Health Canada considers canned tuna to be relatively safe, as apparently the tuna used in canning factories are younger and much less likely to have dangerous levels of mercury in their tissues.
posted by sid at 6:23 PM on January 16, 2006

Seafoodwatch.org says it's ok to eat unless it was caught in the Pacific.
posted by pwb503 at 7:40 PM on January 16, 2006