Skipjack tuna has much less mercury than albacore.

Yes, there’s a big difference — skipjack (canned light tuna) averages about one-third the mercury of albacore.

Skipjack is the fish most often sold as “light tuna.” It’s smaller, so it accumulates less mercury over its life. Albacore (white tuna) is a larger, older fish, and that means higher mercury levels. FDA data puts skipjack at around 0.12 ppm and albacore around 0.32 ppm on average.

That doesn’t mean you should panic about albacore. It just means you might think about frequency. The FDA’s advice for pregnant women and young kids is to skip albacore or keep it to one serving a week. Light tuna gets a thumbs-up for two to three servings.

If you’re the type who eats tuna every day, skipjack is the smarter bet. If it’s once a month, eat what you like. No point overthinking a sandwich.