Tobacco and Alcohol
Tobacco and alcohol are two substances which, in excess, materially retard digestion.
The effect tobacco on the stomach is shown by its action on the small boy with his first cigar. Habituated to its use, the nerves become blunted and the nicotin narcotizes them. The use of tobacco renders the sense of taste less delicate, due to the action of the nicotin on the nerves of the taste buds. Men who use tobacco in excess miss the pleasures of taste; all food tastes much alike to them.
Tobacco, due to its action on the vagus nerve, many times causes disorders both of circulation and digestion. The starches are usually not well digested by those who are habitual users of tobacco.
Smoking before meals or when the stomach is empty often occasions nausea.
Because of its narcotic action it often exerts a soothing influence particularly in men of highly nervous temperament who are unwilling to take the necessary exercise to equalize nerve activity.
It was formerly held by physiologists that alcohol was a food, because its oxidation liberates heat, and it was assumed that this liberation of heat was the same as that freed by the combustion of fats, starches, and sugars uniting with oxygen. More recent knowledge, however, has unquestionably determined that the body decomposes alcohol into carbon dioxid and water, thus liberating heat, yet the reaction produces cold and the body requires more heat to warm it.
The blood-vessels of the skin dilate from overstimulation, and heat is radiated faster than it is generated, so that the temperature of the body is really lowered though alcohol gives a sensation of heat. The body, therefore, loses the power to resist cold.
It was formerly used by physicians for its supposed stimulant action, but it has been determined that the apparent stimulant effect is due to irritation of the nerves, particularly of the nerves of the stomach; the temporary spur to activity is followed, however, by depression of the body forces.
The habitual use of alcohol, from overstimulation of the nervous system, affects this system, deranging it permanently, gradually lowering both mental and physical ability, and causing a catarrhal condition of the stomach and intestines.