Protection Enchant Prevents Any Damage from Suffocation + Cactus (Affects Mobs and Player)

I noticed firstly that Skeletons wearing certain armour were not dying from suffocation. Tested further and it was armour with Protection enchantment that they were wearing.

Steps To Reproduce

1. Set to survival at any difficulty
2. Equip any 1 piece of armour with Protection 1
3. Place 2 sand blocks above head so you start to suffocate
4. Notice your health doesn't go down

This can also be tested by standing on or near to a cactus. You will not take damage whilst wearing Protection armour (until it wears out).