Spasmodic bronchial asthma is believed to be occasioned by temporary spasm of the bronchial muscles which narrows the lumen of the tubules and obstructs the free entrance and exit of air. It is also attributed to hyperemia and swelling of the bronchial mucous membrane, and possibly, in some cases, to a reflex spasm of the diaphragm and other muscles of inspiration. Asthmatic patients soon find from experience that errors in diet are liable to precipitate an attack, and overloading the stomach or eating particular kinds of food, which are unwholesome or against which the individual possesses some idiosyncrasy, may excite dyspnoea. Aitkin showed a true appreciation of the importance of diet in this disease when he wrote: "More is to be done for asthmatic patients on the side of the stomach than in any other direction," and " the asthmatic can never with impunity eat and drink as other people".

Accumulation of large quantities of undigested and fermenting food results in the production of gas in both the stomach and intestines, which become distended and by pressure interfere with the movements of the diaphragm and abdominal muscles in free respiration. The chemical irritation of undigested food may be a cause of reflex spasm of various muscles, and may possibly affect those of respiration. It is therefore necessary for asthmatics to exercise care in the selection of their food and to keep the digestive organs in as normal a condition as possible. All food which is constipating or which is liable through fermentation to evolve large quantities of gas should be shunned. In general, fats and sweets should be given up, and starchy food, if eaten at all, must be very thoroughly cooked and slowly masticated, in order that the salivary digestion of it may be as complete as possible. Pork, veal, and cheese must never be eaten, and elaborate cooking and desserts are forbidden. No water should be allowed with meals or until at least three hours thereafter.

A cup of very hot water may be drunk an hour before each meal and again at night.

In most persons the asthmatic attacks are worse at night, and in many they only occur at that time. It is consequently better for them to take the principal meal of the day at noon and to eat a light supper, so that gastric digestion may be finished before going to bed.

The following diet may be offered as giving a general idea of the regimen for somewhat advanced cases:

Breakfast

Bread and milk or well-cooked oatmeal porridge or wheaten grits without sugar (lemon juice may be added instead). A chop or a little broiled fresh fish, coffee without sugar.

Dinner (Not Later Than 2 P. M.)

Beef or mutton, bread, one or two green or succulent vegetables, such as spinach, stewed celery, stewed or raw tomatoes. Blancmange or custard (not sweetened), or a little rice pudding. Fresh fruit in season, such as a peach or baked apple.

Supper (6 P. M)

A soft-cooked egg or a little cold fowl or game, stale bread, toast, or zwieback, milk, stewed fruit (without sugar).

Patients should eat very moderately, masticate thoroughly, and take their meals with punctuality.

Among beverages, coffee without sugar is better borne than tea. Loomis believed that "not infrequently a paroxysm of asthma can be warded off by taking two or three cups of strong coffee immediately upon the accession of the first asthmatic symptom".

During an attack non-alcoholic patients may take a hot strong lemonade with whisky or a hot brandy and soda. Malt liquors are forbidden.