Sources: Papers On Health
Digestion is the process whereby the food we eat is turned
into material fit to be assimilated by the blood. It begins in the
mouth by the mechanical grinding and crushing of the food, and the
chemical conversion of the starchy part into sugar, in which form alone
it can be assimilated. This conversion is carried out by the saliva.
Hence the necessity for thorough mastication, even of sloppy foods that
do not seem to require it, and for attention to the teeth in order that
they may thoroughly chew. Alcohol and tobacco, as they spoil the
saliva, are very unfavourable to digestion, and should always be
avoided. Twenty minutes longer to chew one's dinner is worth a whole
box of pills, and no one need expect good digestion who neglects
thorough chewing and salivation of the food. This may, with advantage,
be increased to an extent which most people would think quite absurd.
It has been proved that when all food is chewed until completely
reduced to a liquid, its nutritive qualities are so increased that
about half as much will suffice. This is of immense importance in all
cases of weak digestion, or indeed whenever an absence of vigorous
health renders the economy of vital energy important.
In the stomach the food meets with the gastric juice, which has the
property of turning proteid (see Diet for the various substances
contained in food) into material ready for assimilation. The walls of
the stomach are muscular, and their contraction churns the food with
the juice. The gastric juice is secreted by glands embedded in the
walls of the stomach, and is poured out when food is taken.
The whole food, now in the form of a paste, passes into a pipe about 12
inches long (the Duodenum), into which pours the secretion of the
pancreas and that of the liver (bile). The pancreatic juice acts upon
the starch which has escaped the action of the saliva, and also
continues the work of the stomach. It furthermore emulsifies the fat or
divides it into extremely fine drops.
The food passes now into a long coiled pipe--the small intestine. This
secretes the intestinal juice which further assists the pancreatic
juice. Absorption has been proceeding from the stomach onwards (see
Assimilation). The mass of undigested food is pushed along the small
intestine by means of muscles in its walls and passes into the large
intestine where a similar process to that of the small intestine goes
on, the remains of the food ultimately reaching the vent in a semi
solid form, consisting of the undigested part and the debris of
During this complex process much blood and energy is needed for the
abdominal region, therefore hard work or exercise should not
immediately follow a meal. It will be noticed that each stage of
digestion prepares the food for the next stage e.g., the mouth
prepares the food for the stomach. Now, as the food ceases to be under
our control when it leaves the mouth, every effort should, as we have
said, there be made to prepare the food for its reception by the
stomach. Chew food dry as far as possible, for that excites saliva. It
is best not to drink till after the meal. The digestive powers often
become weakened in advancing years, but may be greatly preserved, and
even restored to health after long debility, by careful attention to
the above hints.
Drinks made of lemon juice or orange juice and water are often very
good to help an invalid digestion, but nothing is better than sips of
hot water for some time before a meal. Distilled water is especially a
most valuable drink. Cooling applications to a fevered stomach and warm
fomentations to a cold one will often promote digestion marvellously.
The feet and legs may be fomented if cold while the cold cloth is
pressed over the stomach, especially if the process be long continued.
Where heat is necessary it should be gradually and cautiously applied,
so that sickening the patient may be avoided. (See also Assimilation,
Food in Health, Indigestion).