Navy beans are a very good source of manganese and a good source of copper, trace minerals that are essential cofactors of a key oxidative enzyme calledsuperoxide dismutase. Superoxide dismutase disarms free radicals produced within the mitochondria (the energy production factories within our cells). Copper is also necessary for the activity of lysyl oxidase, an enzyme involved in cross linking collagen and elastin, both of which provide the ground substance and flexibility in blood vessels, bones and joints.