This is not a tongue-in-cheek question. Nor is it a nasty one. There really is something to be said about that corn in the toilet bowl. No matter how you chew it, corn always comes out in kernels.
Corn’s outer coating
The most acceptable explanation is that when we chew corn, the kernel’s outer layer merely comes off. The yellowish outer layer is made of cellulose. Cellulose cannot be digested, so it goes in and out of the digestive track intact. When you poop, corn bits form up in kernels, and the inside parts that are made completely of starch is the thing that gets digested.
Scientifically our digestive tract has not reached a point in evolution where we can easily digest corn. Thousands of years ago, when cooking wasn’t invented, humans were mainly vegetarians. Hence our daily fare consisted mainly of root crops and raw vegetables. That went on for thousands of years, so that our digestive system could not stand less digestible food such us animal meat.
It’s worth noting that at the time, our digestive tract was much longer, and our appendix bigger. If you take a closer look at the profile of primitive men in those days, they had bigger molar teeth and their incisors appeared smaller compared with ours. That’s the beauty of evolution: our food today has become far more digestible and easier to eat than food thousands of years ago. For one thing, we cook our food to make them palatable and tender to the mouth and teeth. Our jaws have become smaller, and it appears that our wisdom teeth have shrunk deeper. Because we don’t have much use for them, we can even make do without them. Some people don’t even have real teeth at all!
In the old days early man had to use force in eating food. Non-soluble fiber and plant cell cannot be digested, such as corn’s outer coating. As for the starchy filling, it can be easily digested and converted into cellulose by the enzymes in our mouth. It seems, however, that our ability to break down cellulose has been disabled over time. Aside from shrinking, our appendix has been observed to be incapable of breaking down carbohydrates as much as it used to.
Chewing as the first stage of digestion
With smaller jaw and teeth, we have to chew our food really slow and well to achieve full digestion. That’s where it gets tricky with corn. We take the corn bits for granted and gobble up the kernels, so our digestive track gets in trouble. Notwithstanding tough kernels, our digestive track has to slug it out with corn’s outer slippery coating. In our stomach the kernels remain intact against the onslaught of acid, so they go through all the way to the exit.
There’s a remedy to this: when eating corn and all food in general, we do our digestive track a favor by eating slow. Chew every single bit well. By doing so, tough and mouth enzymes act on the food. Digestion, then, starts in the mouth.
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