Tuna
It’s not about tuna itself, but the fact that it could contain high levels of mercury. Certain types of seafood like shark, tilefish, tuna, swordfish, marlin, and king mackerel could be contaminated with high levels of mercury. Studies suggest that people who have high levels of heavy metals like mercury in their bloodstream can have a 5 percent decrease in cognitive function.
However, it doesn’t mean that you should remove seafood from your diet for good. Kirkpatrick suggests eating potentially mercury-contaminated fish like tuna no more than once a week. Ahh, and bear in mind that the older the fish, the greater the chances of having high levels of mercury.
If you really want to make sure that you consume the best of the best, get your brain-friendly omega-3 fatty sources from wild salmon or lake trout.
