I do believe it, though calling them "superfood" is just hyberpole. Food has traditionally been used as a form of medicine for many thousands of years. We have just lost touch with our roots and our animal nature and now need reminding of it! If you observe animals closely, they will eat what they need at different times to suit different needs. This all that the hype about superfoods is really doing - re-educating us about how food can help and heal as well as feed us.
As for which ones do I eat, well.... depends what you consider to be a superfood I suppose! Quinoa, blueberries, salmon, kale, broccoli, grapefruit, amaranth, flaxseed.... all form part of my diet.