[Dr. Sivana]

Grains — all of them — are poison.

Man does not live on bread alone, but he does live on bread. Our Lord served grains at the Last Supper. Matza is an important part of Passover. In most parts of the world, grain was one of the few ways to store food long term to allow civilization itself to develop. No canning or refrigeration was available.

If you like, you can make a case against modern processing of grains (pesticides, hybridization, GMOs, etc.) but calling all grains poison is a stretch.

[Lazamataz]

If you eat any grain whatsoever, make vertical slits in your wrist and enter a hot-water bathtub.

The results will be the same, but the latter will be quicker.