They have far fewer nutrients than they did a few decades ago, but experts still urge people to keep eating what amounts to produce-shaped cardboard. You want people to have a healthy diet? Send them to a farmer's market for heirloom crops, preferably grown with organic or biodynamic methods that nourish the soil. If you grow your own, prefer heirloom varieties to modern hybrids. Another option is wildcrafting: anything growing on its own hasn't been bred stupid, although you may still have to contend with soil depletion.