This table provides guidelines on how much canned tuna it is safe to eat, according to the Environmental Protection Agency. While mercury poses the most serious health threat to children and women who are pregnant or planning to become pregnant, others may also wish to use this list as a guide.
If you weigh: Don't eat more than one can every- White Albacore - Chunk Light
20 lbs 10 weeks 3 weeks
30 lbs 6 weeks 2 weeks
40 lbs 5 weeks 11 days
50 lbs 4 weeks 9 days
60 lbs 3 weeks 7 days
70 lbs 3 weeks 6 days
80 lbs 2 weeks 6 days
90 lbs 2 weeks 5 days
100 lbs 2 weeks 5 days
110 lbs 12 days 4 days
120 lbs 11 days 4 days
130 lbs 10 days 4 days
140 lbs 10 days 3 days
150+ lbs 9 days 3 days
Source: Food and Drug Administration test results for mercury and fish, and the Environmental Protection Agency's determination of safe levels of mercury.
Enter your weight, pick the type of fish, how many oz you eat a week (a can of tuna is 6 oz I think) & it will calculate how much mercury you're getting. I was surprised at the results I got!
For reference, the University of Northwestern has a list of tuna and other fishies as well:
and the American Heart Association:
I'm going to throw this out there - you probably shouldn't be eating anything from the top of the food chain mercury or not; we need those big fish in the oceans. Don't forget to check your local Seafood Watch in order to see what fish is the most environmentally friendly to eat.
But yes, mercury accumulates in the food chain - vegetarian fish have the lowest amount, the fish that eat them have all the mercury from all the fish they eat, the fish that eat those fish have the combined mercury of all the fish lower than them, and so on and so forth. Add to that the fact that there are 5-7 layers to the food chain in the oceans (as opposed to on land where there are only 3), so by the time you get to tuna, that's a whole lot of mercury concentrated in one fish.
Edited to add: Long line fishing has put 19 of 21 albatross species on the critically endangered list, plus long line fishing has a high degree of associated bycatch (sharks/turtles etc); just another couple of reasons to avoid tuna.
Original Post by sonini:
Wow. That's a little scary considering I was eating a can a day there for a while!
And that mercury accumulates in your body and basically stays forever. So even if you're not planning to have kids for a looong time you need to watch your mercury consumption.