Hi Peter,
It wouldn't surprise me regarding wheat, I'm wondering (coming from a novice bushcrafter) that we probably should adopt to some degree, a more 'cave man' foraging style diet. Sea-weed, shell-fish, game, wild greens (Burdock, Nettles, Cat-tails, etc.), nuts, seeds & berries. I think I'll be OK with all that, apart from mussels, limpets, cockles, etc. as I'm a bit wimpy when it comes to that stuff LOL.

Also, not ruling out the medicinal benefits of certain mushrooms (e.g. Birch Polypore), Plaintain, Dandelion (the roots, according to one study on a US .gov web site have cancer-killing properties).