Q I was told that blending fruit is very wrong. According to this theory, being liquid blended fruit, unlike what happens when eating sliced fruit, would not combine with digestive enzymes and therefore would flow down (passing quickly through the stomach and the small intestine) directly into the large intestine. This would not contribute to the production of large, soft, bulky stool. Bottom line: blending fruit will prevent the “good fibers” to do their “cleaning sponge effect” and to promote regularity. Is that true?
A As far as I’m aware, whether a fruit arrives in our bodies blended or unblended has no significant bearing on the enzymatic action of digestion. If anything, I would surmise that the opposite is true: that blended fruit would get digested more thoroughly. This is because blended fruit presents with more surface area than sliced (and chewed) fruit, so the enzymes would come into contact with more of the food.
This logic follows the natural tendency for us to chew our food: it is the first step of digestion, because as the food starts to get broken down mechanically (chewing), it also begins to chemically break down because of the (carbohydrate) enzyme in our saliva. With regard to the theory that blended fruit would flow down directly into the large intestine: Pre-blended fruit would probably go through the body a bit faster than whole fruit, because a machine has already done the work that the body would have done (mechanically breaking down the food). But this does not mean that digestion is compromised; it does not speed like lightning through the belly and small intestine, only to get dumped directly into the large intestine.
Finally, whether a whole fruit arrives blended or whole shouldn’t have a substantial effect on the stool, at least not in healthy people. The same amount of fiber and liquids get digested, so by the time the blended or unblended fruit hits the bowel, it should be in almost the same state. There may be slightly larger pieces of undigested fiber in the non-blended fruit, but this should not significantly impact regularity. Please note that fruit juice is completely different than blended whole fruit: juice will not promote regularity as whole fruit (blended or not) would.