The black-eyed pea, black-eyed bean or goat pea, a legume, is a subspecies of the cowpea, grown around the world for its medium-sized, edible bean. Their 5 grams of protein represents 9 percent of the recommended daily intake for men and 11 percent for women. As with all legumes, black-eyed peas are especially good sources of soluble fiber, which helps prevent type 2 diabetes by keeping blood sugar balanced after you eat.