The chewing of tobacco causes the loss of much saliva which is needed to help digest the food. Anyone who tires his jaw by chewing tobacco is not likely to chew his food well. Some of the poison in the tobacco is taken into the body through the blood vessels in the lining of the mouth. This is shown by the fact that a boy not used to tobacco becomes very sick after he has chewed a mouthful for only ten minutes.
Smoking and Digestion.—Some persons think that the smoking of a cigar after a meal helps digestion. It may do so in some cases. If a lawyer is much excited about a case he is trying, or a business man is in trouble about his losses, the thinking causes the blood to flow to the head when it is needed in the stomach to give out digestive juices.
The taste of the tobacco smoke may cause some gastric juice to run out into the stomach, but at the same time it is likely to hurt the nerves of taste so that food cannot give so much enjoyment as when the nerves are unharmed. Although smoking may at the time help digestion a little, the poison in the tobacco may afterward injure the body. This poison is especially harmful to growing bodies, and boys who are wise will refuse to smoke on all occasions.
Beer and Digestion.—Some people drink beer with their meals because they think it makes the food taste better. It really prevents them from getting the full taste of the food because they wash it down before it is well soaked with the saliva.
Fig. 29 —The stomach, showing the arrangement of the muscular fibers which alcohol may hinder from doing good work. At the right a piece is cut out of the top layer of muscle.
The flavor of beer may sometimes cause an extra flow of gastric juice into the stomach, but the alcohol in the beer is likely to make the movements of the stomach slower. This prevents the food from being well and quickly mixed with the juices. Several glasses of beer used at one meal will make the stomach do its work very slowly, and it will not do it well.
Wine and Digestion.—Wine is taken by some people to give more appetite for food. It is likely, however, to do more harm than good because the alcohol in it makes the muscles which mix the food in the stomach act more slowly. Some of the food may sour before it gets wet with the juice. Much wine used at a meal is always harmful.
Natural Appetite.—If one is in health, he should feel a desire for his food at every meal. This desire for a reasonable amount of food is a natural appetite. Fresh air and exercise will do much to give one the right kind of an appetite. The eating of much sweets and the breathing of bad air are likely to spoil the appetite.