When: May through October. In many areas, you can harvest them yourself; visit PickYourOwn.org to find a farm and see what's available when.
Why: These berries—one of the few foods that are naturally blue—have sky-high levels of antioxidants, which combat the damage done by inflammation. Anthocyanins, the natural plant compounds that give blueberries their deep color, may have antidiabetic effects as well.
How: Aside from go-tos like pancakes and smoothies, blueberries also add a sweet kick to grilled pork.