In the average size man, the digestive system is an amazing thirty-six feet long, beginning with the mouth and ending with the rectum. The purpose of digestion is to break down insoluble pieces of food into soluble molecules, thus enabling vital nutrients to be absorbed into the bloodstream. Even though the digestive system works as an integrated unit, for the sake of clarity, we shall take a brief look at the function of its various parts. This will give a clearer understanding of what is happening should things go wrong, and, most importantly, how to deal with such problems.
Digestion in the mouth
Digestion begins as soon as food enters the mouth, by the action of chewing and by the secretion of saliva.The food then begins its long journey, passing through the throat and into the oesophagus (food pipe). To prevent the food falling too quickly into the stomach and causing indigestion, the epiglottis, which is a valve-like muscle, sits perfectly over the trachea (windpipe). The epiglottis also prevents food from entering the airway and causing choking. However, choking may occur if pieces of food arc inadequately chewed and hurriedly swallowed. When we eat slowly, the valve opens and doses where the oesophagus enters the stomach, passing along a little food al a time by the action of peristalsis.
Digestion in the stomach
The stomach is tucked up in the abdomen at the lower rib line. While in the stomach, the food is churned by muscular contractions of the stomach wall, and converted into a semi-liquid state by being mixed with gastric juices – mainly hydrochloric acid – secreted by numerous glands in the stomach lining. The liquid ‘gruel’ is then released from the stomach at regular intervals by the opening of the pyloric sphincter, from where it enters the duodenum – the foot-long first part of the small intestine.
As the gruel passes through the duodenum, alkaline secretions from the gallbladder and pancreas are also poured into it. Pancreatic juice – about two pints a day – pours into the duodenum, acting to neutralise the acid gruel. The gall-bladder acts as a storage for bile, which is produced in the liver. Bile is a green, alkaline liquid which breaks large fat globules into minute globules, thus enabling the pancreatic enzymes to process them.
Food is moved through the digestive system by means of muscular wave-like contractions known as peristalsis. When the digestive system is working normally, there are 10 to 15 of these movements a minute. It is by this action that the gruel is pushed into the ileum. The lining of the ileum is covered by millions of villi – microscopic finger like projections. Their job is to convey nutrients from the liquid food into the bloodstream. The undigested material, chiefly cellulose from plant cell walls, dead bacteria, and dead cells, is passed out through a sphincter muscle into the colon or large intestine.
The large intestine (colon and rectum)
It takes three to eight hours for the gut to process a meal. Once in the colon, water is extracted from the gruel and passed back to the blood. A semi-solid waste remains. Finally, this is expelled through the anus.
The role of the liver
The liver is the largest organ in the body. lt is responsible for upwards of 500 vital functions. And in one way or another is involved with all the physiological processes. As well as governing the secretion of bile, the formation of blood, and the production of heat, it provides muscle fuel (glycogen), processes dietary fats, and manufactures vitamin A. The liver also deals with detoxification; so important is this process that if the caffeine and various drugs we might take were injected into exit vessels leading to the heart, we would be dead within minutes. Inject them into the entrance vessels of the liver, and the ‘sting’ is extracted within six to ten seconds – the time it takes for the blood to pass through the organ.
Patterns of digestive disorders
Apart from the importance of eating a healthy diet and living a balanced lifestyle, the functioning and health of the digestive system is closely related to our emotional state. For instance, everyone at some time in their life has
experienced a ‘gut reaction’ to powerful emotions such as anger, fear and anxiety. This may have simply resulted in a momentary tightening of the abdomen, or a fluttering sensation in the solar plexus area. However, prolonged stress can lead to disturbances, ranging from diminished appetite, constipation and heartburn, to diarrhoea and nausea. Or, more seriously, a gastric ulcer or irritable bowel syndrome.
Incidentally, just like the skin, the stomach flushes with anger and becomes pallid with fright! And when we get excited it reacts with vigorous contractions. One reason why some people lose their appetite and/or get constipated when they are depressed is because peristalsis all but stops, and so does secretion of gastric juice. If we ignore the signals and carry on eating, what we swallow just sits there, causing bloating and discomfort. Worry and anxiety cause the stomach to produce excess acid. Such emotions may also cause acid from the stomach to regurgitate into the oesophagus, resulting in heartburn. Therefore, whenever you feel under stress, it would be wise to change your eating habits, as well as taking steps to reduce the stress through aromatherapy massage and/or relaxation exercises. Eating a number of small, light meals is the best way to control excess acid which, if left unchecked, may cause ulceration in the lining of the stomach or duodenum. However, even if acid has already begun to eat into the mucous membrane causing twinges of pain, this can be reversed in the early stages. As soon as you begin to relax, the stomach will pour out mucus to heal the wound. So as with almost every other condition mentioned in this book, holistic treatment (which takes into account the emotional state of the sufferer) is essential. Bearing this in mind, the following charts suggest natural treatments for a number of common ailments affecting the digestive system.
The limitations of aromatherapy
There are numerous herbal remedies that have a beneficial effect on the digestive system. However, because essential oils lack certain constituents such as bitters and demulcents, their action on the digestive system is some¬what curtailed. Taken internally, bitters promote the flow of saliva and gastric juices in a complex way via the taste buds and a reflex action in the brain, whereas demulcents soothe and protect an irritated or inflamed digestive tract. However, external treatment with essential oils in conjunction with herbal remedies becomes an effective healing tool for digestive ailments, but more especially for long-term problems such as chronic constipation, nervous indigestion and the prevention of gastric ulcers in prone subjects.
It is interesting to note that inhalation of certain essen¬tial oils can be helpful for digestive disturbances triggered by nervous tension. In fact, the aromatic molecules reach the bloodstream faster by inhalation than by oral administration. The problem is knowing how much to inhale. My own approach is to rely on internal doses of herbal remedies for an acute condition, such as an attack of heartburn or colicky indigestion, and to use aromatherapy (especially aromatherapy massage) as a preventative measure.
Actions of essential oils
The principal actions of essences which have an affinity with the digestive system are as follows;
Antispasmodics: For spasm and pain, for example chamomile, fennel, peppermint.
Aperitifs: The aromas of most essential oils stimulate the appetite; good examples include bergamot, ginger, orange.
Carminatives and stomachics: For flatulence and nausea, for example cardamom, fennel, peppermint.
Cholagogues: For stimulating the gall-bladder. and thus the flow of bile, for example, lavender, peppermint.
Hepatics: For strengthening, toning and stimulating the secretive functions of the liver, for example, lemon, rosemary, peppermint.