Fish + Broccoli
The benefit: You can sock it to cancer with this one-two punch.
The science: Tuna and halibut contain selenium, a mineral that raises your levels of a cancer-fighting enzyme called thioredoxin reductase (TR-1). Likewise, broccoli provides sulforaphane, a plant chemical that also boosts TR-1. When British researchers combined these two nutrients, they noticed that the tag team was 13 times more effective at slowing the growth of cancer cells than each was individually. The scientists believe that as selenium concentrations in your cells rise, the ability of sulforaphane to elevate TR-1 increases.