Another example: oxalic acid.  Like phytic acid, oxalate binds to
iron and interferes with its absorption.  While phytate is found
mainly in grains, oxalate is found in tea, spinach, rhubarb, and
sardines -- all paleo foods.  I mention these foods because they
are rich enough in oxalate that doctors typically tell people to
avoid them if they have a problem with oxalate kidney stones.

Todd Moody

  Would these foods be plentiful enough, in nature, to wreck as much havoc
on a human, who eats a much broader food range, and has a stronger immune
system? I would think that phytates and an agrarian diet would be far more
detrimental to health. In small amounts, oxalate, is probably handled well
by a paleo eater, who occasionally comes upon types of food with oxalates.
The oil is not very likely to be paleo any how.  Whole foods are, and we
need to look at the amount of consumption of any one type of food, as it
would be found in nature, on average.