This is certainly a reason why I prepare all my grains properly remove all of the phytic acid. All that is required to removed phytic acid is soaking your grains overnight in a slightly acidic solution (you can add a bit of yogurt, lemon juice, or vinegar) and then cook the grains like normal after they have been soaking for ~12 hours. You can do this with rice, oats, or any grain.

Another way to remove phytic acid is by fermenting grains, and sourdough bread shouldn't have any phytic acid due to the bacterial fermentation.

Most traditional cultures did soak there grains overnight before they made porridges and ate sourdough bread, which made the minerals much more available to the body. Porridges also cook much much faster after soaking overnight.

Also, if you sprout or soak nuts in a brine it will remove the phytic acid.

If you do this you can still enjoy grains and they will have better ratios of copper to available zinc.