I love canned tuna food – love it far more than fresh. I stockpile cans of it knowing I am never more than a can-opener’s ride away from a perfect sandwich.
I was always a “solid white” (not “chunk light”) person, thinking the darker flesh the lesser of the two and sourced from the scraps – those parts of the fish not white enough or solid enough to make the grade. Then I learned the truth – the “white” and “light” are not even from the same fish and in fact it’s the darker ie “chunk light” tuna flesh that is superior (from a health angle) with 3x less mercury than the white. Here’s why:
Tuna only looks small in a tin. In the ocean it’s big. Very big – you can fit about 5,000 tins of tuna into a tuna. Because of its commanding place on the food chain, it eats a lot of big fish (which have mercury in them) which means that by the time it’s killed, enormous amounts of other fish’s mercury have accumulated in its own flesh.
Mercury is bad. It’s especially bad for pregnant women and children. All tuna has some mercury but some tuna has far less. The smaller the tuna, the lower the mercury.
Albacore tuna (labeled “solid white” ), is the biggest of the tuna family and hence the worst offender. Skipjack and Tongol (labeled “chunk light”) are the smallest. This smaller size makes such a difference in mercury levels that guidelines suggest that one can eat these tuna 3x as frequently as white Albacore. For example, if you’re a 150lb adult, you are advised to limit your consumption of a can of white tuna to once every 9 days, but you can safely indulge in a can of “light” tuna every 3 days!
So if you’re a “solid white” person try the “light”; by can #3 you’ll be over the white and never look back.
Bonus tip: choose canned tuna food rather than oil-packed. When you drain oil-packed tuna, some of its natural omega 3 fatty acids leech into the added oil and go down the drain. But since oil and water don’t mix, water-packed tuna won’t loose any of its precious omega 3s when you drain the water.