what makes a leaf of lettuce more digestible than other leaves?

Question

It’s clear that our stomachs can’t break down most greenery around us, like ruminants with 4 stomachs can. But what makes one leaf digestible to us and another not?

In: 27

Answer 1

Cellulose. Humans lack the enzyme cellulase thus leaving us unable to digest plants that are high in cellulose. However, a plant like lettuce has a relatively low amount of cellulose compared to other natural greens and leaves, and contains a higher amount of digestible material and our body just filters the cellulose through the stomach undigested which it is able to do since the amount is low.