Are you living in a non-fish culture like me?
I do like fish but they're not fresh where I live nor are they easy to come by. Sure some restaurants serve some nice sea-food but they're not reasonably priced.
Now, I'm complaining about this since fish, especially salmon and sardines are high in omega-3 fatty acids. These acids are believed to have properties that fight cancer.

The only fish-dish which is easy to come by is tuna, but you don't want to stick to the same type of fish all week. If you like tuna like me, you're on the right track, just try to add one or two more types of fish a week. Fish is also good for your memory too.
That'll do the trick.