Why do we eat plants if we can’t digest cellulose, ie, plant cell wall?

Question

Title says all. Plant cells are covered by cell wall made of cellulose. The human body doesn’t have the enzyme cellulase to digest it, so why do we eat them? Do they just pass through us? If so, why are they ‘healthy’?

In: 55

Answer 1

Humans have ability to cook food. That drastically alters bioavailability of nutrients and digestion is easier etc. Some might even go so far and say it’s one of the most important abilities that made us human.