"It is a fallacy," says Dr. Oswald, "to suppose that hot spices aid the process of digestion; they irritate the stomach and cause it to discharge the ingesta as rapidly as possible, as it would hasten to rid itself of tartarized antimony or any other poison; but this very precipitation of the gastric functions prevents the formation of healthy chyle. There is an important difference between rapid and thorough digestion." It is evident he is here contrasting rapid (and premature) emptying of the stomach with thorough digestion.
All condiments act as irritants and, as a consequence, induce inflammation in the digestive tract. Their continued use results in hardening (toughening) of the mucous lining of the alvine canal. This hardening renders the delicate membranes less sensitive to their irritating qualities, but cripples the efficiency of the membranes. Cayenne or red pepper is about the most fiery of all condiments. It burns and "stimulates" these organs and is followed inevitably by a reaction with a corresponding lowering of the vital tone of these same organs.
The effect of condiments is the opposite of what it is popularly supposed to be. They depress and hinder rather than aid digestion. The taste of condiments is repulsive to infants and those unaccustomed to their use.
The irritation caused by mustard, pepper, pepper-sauce, horseradish, cayenne, capsicum, and other hot and exciting substances, due to highly poisonous essential oils, which, in the pure state, quickly produce blisters upon the skin, and which in condiments when taken internally, exert their irritating effect upon the more delicate membranes of the digestive tract, excite the stomach to increased action in certain respects, but lessen the secretion of gastric juice and, later, decrease activity of the stomach. Mint and thyme lessen the activity of the stomach and diminish secretion. These substances "act" upon the digestive organs as a lash but the spasms they induce do not accelerate digestion. Their irritation, though temporarily increasing the tone of the mouth and throat "burn" like a coal of fire. If pepper is taken by the non-user its burning may be felt in the stomach. It may even result in diarrhea. When it passes out with the stools on the same or the following day the non-user experiences the same irritation and burning in the rectum that he experienced in the mouth and throat when he ate the pepper. If it is habitually employed nature is compelled to thicken and harden the membranes of mouth, throat, stomach, intestine and colon to protect these against its influence.