Opt for purple Graffiti and green Romanesco cauliflower—they can contain twice the antioxidants as the white kind we commonly buy.
Say no to baby carrots. Since their outer layer is stripped away, they lose one-third of the antioxidants. Buy a bunch with the greens attached and cut them into sticks yourself.
Go for the ones that bring on the tears. In a lab study, extracts from strong-tasting onions were more effective at killing liver cancer cells than those from mild onions.
To test for freshness, rub two stalks together. If they squeak, buy 'em. Fresh asparagus still has a waxy coating that creates the sound.
Next: 5 foods that should never be in your grocery cart